Hello!

Everything started with this work here:
https://www.diyaudio.com/forums/multi-way/328970-klangfilm-spherical-wave-horn-calculator-round-elliptical.html

Now, after a long time of research and programming I would like to introduce my new website:
Sphericalhorns – This is an exclusively private blog about spherical horns without any commercial interest.

The first two theoretical "papers" have been published and the next is in the making for the Kugelwellenhorn. This would be also the time when I will provide my spread sheet calculator to the community.

Have fun!
docali

Greetings Friends. I did a little amp swapping the other day and was surprised at the lack of bass coming from a Dynaco P-P amp I built a few years ago as compared to my daily amp, a 6B4G SET and was wondering why. Here's the schematic as built:



The amp in question was built using 2x PCBs with a circuit called "Dynaco 6V6 P-P" that features a 12AX7 in Floating Paraphase driving a pair of EL84 to about 10 watts. I used Edcor CXPP10-8k outputs with 4 and 8 ohm taps and wired the feedback to the 8 ohm tap. It was mentioned in a thread I started upon completion of the amp that the original Dynaco product used a different, higher-quality OT and adjustments to the Fb loop might be required. Using a simple scope and a 10kHz sq wave I minimized ringing by increasing the value of the cap in the Fb loop.

First listing to the amp gave a disappointing lack of bass when my Polk Monitor 60 speakers were connected to the 8 ohm taps, and better bass when wired to the 4 ohm taps - the Speakers show about 5 ohms of DC resistance from a DMM. But I get much more bass from my 6B4G SET amp hooked to those speakers - and that amp makes "only" 3 watts. So I'm wondering what I can do to improve the bass from this P-P amp. The original amp had the Fb loop connected to the 16 ohm tap, I only have 4 & 8 ohm - is this a problem? would changing the value of the Fb resistor compensate? Or do I just need new iron?

thanks for taking a look!

I am guitar player and HI-FI enthusiast. Looking forward to exchange ideas with like minded people.

To begin with: It is well known that the step response of an ESL63 is not perfect.



It's only near perfect. Unfortunately, there are some and also publised anomalities of the decay after some 0.4ms or so. Would there be a way to smooth these very early jaggies?

And then, there are these ugly four vertical parallel aluminium profile bars, each one with it's own resonance. You may eventually try to damp this by applying a felt interlayer, touching both the individual bar and the outer, protective metal grid. I already have made such a mod on my ESL63, but that seemed not very efficient after all. As the grid itself is not acoustically clean and may rattle, only slightly damped by the sock.

So I experimented to reduce these two annoyances at the same time. Using bits of PET 24mm thick sound isolating panel material (e.g. Echoboard by echojazz.com), I squeezed and glued small bits between these bars. This material is like a very, very stiff felt and is mechanically stable. The size and the location of these bits have been determinded by a rather long iterative procedure.

Don't be upset while looking at the pictures because of the white colour of the dust protections you see. It's because I fitted my ESL63 with a Vliesseline Stickvlies (https://www.vlieseline.com/Produkte/Kreativsortiment/Stickvlies) as a dust protection instead of the usual BOPET. This thin and dense textile material showed a bit less reflections than BOPET in the wavelet analysis and also has some absorbtive/damping properties. The tradeoff is that this Vliesseline is not sealing, so that microdust is still potentially penetrating to the diaphragm. Therefore, this mod is only good for non-smokers.




On the frontside, from top to bottom, 20mm - 45mm - 55mm - 45mm - 20mm bits of Echoboard. The 3 central bits fit centrally over the panel's boarders.




On the backside, from top to bottom, 20mm - 70mm - 70mm - 20mm bits. The 2 central bits fit the center part of the two segmented panels.




The two native ESL63 showed a step of the SPL towards higher frequencies (the green curve labeled 0-0). The central and frontal 55mm Echopanel does nicely tame this step. A 70mm wide one did damp too much (the brown curve labeled 1_large-0), 45mm a wee bit not enough. Then came all the other pads, on the frontside, and on the backside, more or less positively influencing on the speaker response. And with all the pads squeezed between them, these metal rods were no more singing theirs own tune.


The final fittings and results were quite pleasing.



First of all, the nasty >>>ZOJINNNNGGG<<< metal rods now got absolutely mute. And the frequency response of the naked speakers got nicely smoothed, and finally approx. fitted into a +-2.5dB tolerance band above 1.5kHz (curves xy_AA). Refitting then the metal grid and the sock, things got worse again (curves xy_GS). The two naked (AA like Air&Air) and grid/socked (GS for Grid&Sock) AB-sibling's curves are artificially grouped together. In reality, the SPL curves of both speakers differ by approx. 1dB. By the way: a wavelet analyses shows that the grids are the meanest spoilers in terms of reflections. Then comes the dust cover(s), then the sock. And as the frequency domain correlates with the time domain, also the step response got a bit smoother, more uniform. It still presents the 0.4ms anomaly, however. I did not manage to get it smoother than that. But anyway, a bit of a progress is still a bit of a progess ...

A further, tour-de-force-option to improve on the step response might be to selectively obturate some parts of the different concentric stator aeras. I will not do that.

Dear friends!
I'm looking for affordable DAC chip for diy headphones amp with:
1) built-in USB
2) simple 2 channel analog output
3) dip or soic case (hand soldering)
4) low THD+N
5) under 50$ price

At this moment I found only PCM2704C, that has all these features. Are there better options in terms of sound quality?

Thanks a lot!

I salvaged a pair of mini piezos and was thinking of adding them as super-tweeters.
Do they need a cap? They were originally installed behind 2.2uF?
Do they need a resistor? What does the resistor do?

As promised here is a PCB and construction thread for the preamplifier as designed by Doug Self and published by Jan Didden in Linear Audio issue #5. Both gentlemen have graciously agreed to offer their support to guarantee success of this thread.

This preamplifier is especially interesting in that it includes what Doug describes as a 'comprehensive tone control', that means that both the gain and frequency hinge points for the HIs and LOs are continuously user adjustable.

For the last month I've been using this preamplifier listening to a variety of music and sources. Now that I have gotten used to having comprehensive tone controls at my fingertips I would miss them immensely if they were to disappear!

Another quality of Doug's creation is that it's quiet, so quiet that I have given up attempting to measure it's noise level with my aging AP Portable One test set. Noise level at the outputs is at or near the noise threshold of my test set.

Assuming there is sufficient interest I will offer up a kit of parts for builders amounting to the required IO and main PCBs, 6 potentiometers, 4 PCB mount RCA phono connectors, BOM and a PDF reprint of the Linear Audio article.

The cost for a 2 channel kit will be $65 plus actual cost to ship. Private message me for details if you are interested.

** PLEASE NOTE THAT ...

The latest project DOCs are attached below ...

The latest Front Panel Express files are attached below ...

I have a Knight KN 3050 amplifier that I am currently working on.
It has a nifty output level meter that seems to need a new rectifier.
It currently has one of the miniature two lead selenium rectifier diodes with a red dot by one lead ( never saw one like this before). Schematic says 4ma. What silicon would be appropriate for this replacement?
And would a dropping resistor be appropriate for the different voltage drop?

$595 shipped CONUS. Perfect condition. I bought on Apos. I used it as a dac only, but it has options for fixed and variable output, so can be used as a preamp if desired. Selling because I'm cheapening my system globally. Going to be listing my Hypex preamp and Nilai monoblocks soon too

After months of research on Multiple Entry Horns, I’ve decided to build my own. While there are some excellent designs available, I’ve decided to design my own due to size constraints and budget limitations. My goal is to build a complete system for under €2000, including drivers, amplifiers, DSP, materials etc.

I’ll be documenting the journey and sharing the lessons I learn along the way. Since I’m new to this, I’d greatly appreciate any feedback or suggestions for improvement.

For those unfamiliar with Multiple Entry Horns (also known as Synergy or Unity Horns), I’ll include some resources below. In this post, I’ll refer to them as MEHs.

Why Synergy horns?
Synergy Calc V5
Synergy Patent
SynTripP: 2-way 2-part Virtual Single Point Source Horn | diyAudio
Scott Hinson’s MEH

The Design
Designing this project involved plenty of trial and error with drivers, designs, and Hornresp parameters. First I was going to build a 3-way MEH using four 4” drivers and two 10” drivers per horn + big subs using 15” drivers. However, when I discussed this with my better half, she wasn’t happy with the big size. So I changed it to a more compact design: 30x30cm 2-way MEHs paired with subwoofers.

For the 3-way MEH I got ideas and insights from Syn 9/Syn 10 and Cosynes, Scott Hinson’s MEH and SynTripPs. After deciding to go with a smaller horn, I began exploring more compact designs, such as: Two way synergy Horn, Portable Battery Powered MEH Build and others.

Size
Using Synergy Calc , I calculated the size and parameters for Hornresp. According to Bill Waslo: “with horns, bigger is better!”. While I would have preferred larger dimensions, I had to consider WAF, so I settled on a 30x30cm horn with an 80° coverage angle and horizontal pattern control to 850 Hz. After reading this discussion I changed the S1 value to 5.06 to match the CDs opening area to get a more precise Hornresp Simulation..



Drivers
Hornresp is a fantastic tool for modeling speakers, big thanks to David McBean for his contributions! After countless evenings testing various drivers and parameters, I settled on the following components:

Compression Driver - FaitalPRO HF108 (8Ω) I chose it because it works well in short horns and wide dispersion waveguides and people seem to like it a lot. The recommended crossover is 1300 Hz, which is what I’ll go with in my design.
Midrange - 2x FaitalPRO 4FE35 (8Ω) in parallel - they simulated well in Hornresp and have been used in some MEH builds before.

Hornresp parameters



3d printed horn
The inner section of the horn (shown in light grey in the 3D rendering) will be 3D-printed, while the outer flare will be constructed from 2 sheets of 19mm MDF with a dispersion angle of 130 degrees

The HF108 compression driver has a 31-degree exit angle, so the horn starts with a matching 31-degree angle and gradually transitions to an 80-degree angle at the midrange entry point.

To minimize unexpected cancellation notches, the inner corners of the horn are smoothed with 2mm rounded edges.





Mid driver Port location:
From Why Synergy horns?:

In a synergy horn we put the tweeter at the horn apex, easy enough, but how do we know where to tap in the midrange and bass drivers. We use the rule of 1/4 wavelength. So if we want to cross over from the midrange to the tweeter at 1200 Hz, we would have to tap in at 340/1200/4= 7 cm (2,8"). At the same time the cross sectional area (CSA) at the tap in point with in the horn. should be no bigger than in circumference, than the highest frequency being used in the bandpass. So at 1200 Hz the wavelength is 28,3 cm, so CSA can be no bigger than 28,3 cm, otherwise the hornwalls will no support the frequency. Same thing applies for the bass drivers. If we want to x-over from bass to midrange at 400 Hz, then the axial distance from the apex to tap in is 340/400/4= 21,2 cm (8,3"). This 1/4 wave rule makes sure that the drivers bandpass, is cut off and basically acoustically self terminate. What happens is that the frequency at play, for instance at 1200 Hz, travel toward the apex of the horn and then back again, but this time, 180 degrees out of phase, so a cancellation notch occur. In this way we can acoustically short circuit the bandpass, smart. What this cancellation notch will also do, is to acoustically lower the harmonic distortion above the cancellation notch. This effect can NOT be done electrically ONLY acoustically. This cancellation notch can be as big as -30 dB, so harmonic distortion is also lowered -30 dB. The result is a much cleaner sound, compared to other speaker designs.

Click to expand...

I’m crossing between the mid and the compression driver (CD) at 1300 Hz, which means the port holes for the mid drivers should be within 6.596 cm (calculated as 343/1300/4) of the CD’s exit.

I’ve been wondering if the critical distance is measured from the mid ports to the CD’s acoustic diaphragm or its exit. The CD’s exit seems to work well in previous designs posted here, so I decided to go with that. This approach also simplifies placement by allowing the ports to be positioned farther out.

To ensure I stayed within the critical distance, I decided to shorten L12 slightly (the distance between the CD’s exit and the plane of the mid-entry ports). L12 is 4.28 cm, meaning the centre of the mid-entry port is 5.84 cm from the centre of the CD’s exit, so it’s well within the required 6.596 cm for the crossover.

The circumference of the cross-sectional area at the tap-in point is calculated as 6.531*4=26.124, which is close to the wavelength of 1300 Hz.

However, when I model it in Hornresp, the cancellation notch appears well above 1300 Hz, and the mids start to roll off around 2000 Hz. I can increase the distances well above 6.6 cm before I get the cancelation notch near 1300 Hz. I’m not sure if I’ve missed something in my calculations and the measurements may differ when I measure the build speakers.

Mid driver Vrc:
I made the Vrc (closed rear chamber volume) fairly small 2 L in total (1L per driver). I still haven’t figured out how I will limit the chamber volume. Using tubes like those in the Cosynes would be challenging due to the distance between the mids and the compression driver.

Mid driver Vtc:
I didn’t feel like I needed to minimize the Vtc (throat chamber volume) as the mids can play high enough frequency already. Making it smaller using cone plugs seems more beneficial with bigger woofers (like on the SynTripPs) and also the B&C 4NDF34 which have been used in some designs. For now I’ve estimated 50cc per driver, but will measure the volume when I receive them. I might adjust the sizing after doing the final calculations with the correct volume.

Mid driver port size:
There are 2 entry ports per driver, 4 in total. The entry points are frustrumised, 2.76 cm in diameter closest to the driver and 1.95 on the inside of the horn, which translate to Ap1 of 24 cm² and Ap2 of 12 cm².

The ports are relatively small, with port velocity exceeding 17 m/s when played above 105 dB below 200 Hz. These are meant for home hi-fi use, so I don’t plan to play them too loud. I also don’t want to make them too big, so they affect the CD’s output. The ports are placed next to the corners to minimise the effect they have on the CD.

Vertical drivers:
This is something I haven’t seen mentioned often, and it seems to be overlooked in many MEH designs. I will place all the drivers vertically, on the side walls of the horn, to avoid driver sag.

2. All drivers needed to be nearly vertical. The suspensions of a lot of home drivers will take a set over time if stored horizontal...I've seen it way too often. Since I'm using relatively inexpensive drivers I wanted to avoid this since I don't plan on building myself new speakers every 5 years or so. Source

Click to expand...

Ported or sealed box:
While I was designing the 3-way MEH with 2x 10” woofers I tried modeling the low drivers in both ported and sealed box. I ended up choosing sealed after reading Arts comment from the SynTripP thread.

In retrospect, the 3dB gain the ports provide around Fb are probably not worth the -3dB 350 to 475 Hz and-10dB cancellation at 700 Hz. That upper cancellation requires more output from the HF driver to “fill the hole” in response they cause. Most 3" diaphragm drivers are already excursion challenged in the acoustical crossover range.

To sum up, don’t bother with cutting the port holes, leave the cabinet sealed 😉

Click to expand...

Subwoofers:
I haven’t decided on the subwoofers yet.
I’m considering adding two subs within the same enclosure as side-firing woofers in a push-push alignment. For example, two GRS 8SW-4HE drivers in a sealed configuration with a ca 42L volume. Here is a promising recommendation for these woofers.

If I go with this approach, I might decrease the vertical coverage angle of the MEH horn to 60 degrees to make space for the woofers below the horn. I guess it would be good idea to have the woofers close to the horn, within ¼ wavelength of the crossover frequency, but have also read that it doesn’t matter very much for frequencies below 100 Hz.

Adding the subs in the same enclosure would significantly increase the height of the enclosure, which may not pass the WAF. Alternatively, I could build a separate subwoofer placed approximately 1.5 meters away

Is it better to integrate side-firing subwoofers within the same enclosure or should I make a separate enclosure, which would need to be ca 1.5m away? I’d appreciate any feedback or suggestions on driver selection!



Amplifier and DSP:
As I don’t own any of the parts needed I have the opportunity to build the whole system from scratch.

The TPA3255/51 amps seem to offer great value for the money.
I’m looking into: Fosi ZA3, AIYIMA A70, Topping PA5 II and the upcoming 3e audio amps. I haven’t decided yet and would appreciate any recommendations.

Finding a DSP solution that fits the budget has been tricky. High-quality DSPs can be expensive, while the cheaper options often come with limitations.

I’ve decided to go with a Raspberry Pi 5 running CamillaDSP. For the DAC, I’ll start with the cheapest option: the AliExpress cards mentioned in this guide. RPi 5 Quad Stereo Sound with PCM5102A – Simple DIY Electronic Music Projects. User dptucunduva has had good results with it.

The reasons I chose it are:

It’s cheap and has good potential for upgrades. I can switch out the DAC module for a proper sound card like the Motu Ultralite mk5.
It’s a very flexible system, the Raspberry Pi can act as a streamer and allows for lots of add-ons like a remote controller, Those who use CamillaDSP seem very happy with it.
HiFiBerry DAC, which uses the same DAC chip seems to be decent according to the measurements here. I’m not expecting any fantastic results but see it as a cheap solution that has all the active crossover functions needed.

Next steps:
The CD and mid-drivers are on their way, and I plan to begin 3D printing the horn in early January. In the meantime I’ll focus on refining the horn design, adding mounting holes, figure out how to do the right vrc size. I also need to decide which amplifiers to use and start building the Raspberry Pi DSP. Additionally, I’ll work on designing the subwoofers and determining whether side-firing woofers are the best option.

Any suggestions or input would be greatly appreciated!

As the thread title. Not too fond of the previous models as these did not have USB ports but this one has. So I am curious how it looks and how it performs especially via USB. The reviews are raving but maybe we should take those with a grain of salt 🙂

Hello everyone may I introduce myself....I'm Fabio 60 years old and I like jazz and heavy metal...I'm interested in diy loudspeakers

🙂🙂

no signal, bridge.


5hz.


100hz.


2khz.

10khz.



20klhz.


50khz.


100khz.

300khz.

senoidal 20khz.


the preamplifier.

1.177 / 5.000


Hello, first of all I want to make it clear that, as almost everyone knows, Chinese advertisements and clones often do not even look like what they advertise. In this case, I want to make known what I consider a bargain. Leaving aside the title we have a preamplifier that I consider excellent, at a ridiculous price of 10$ with shipping (at least to Spain), small size (easy to connect if you want an integrated amplifier), you only need a 15-0-15 v. transformer, or a switched source for example of equal value for another 7$, it has its regulators, with its capacitors that really work very well, at the input it has an OP JRC-5532D, then BC550 and BC560, everything quite normal, I ordered 2 units, assembled it and passed it through the oscilloscope, the result is excellent (in my opinion and the price) I put captures of up to 400khz in square wave, the sine wave logically better, it responds from 5hz without problems, I have tried other clones and other originals that I have, and this one on paper gives better measurements, something that measures well can't sound bad. The sound, the little I have tried so far, is quite good, better than the Denon 1500pra that I have.
and other clones except the PASS 1.7, for me it is better for more detail, dynamics and width, but for the price it is gold, now here come the more technical forum members (I am not) who could suggest improvements, for the already excellent preamp, I attach captures from the oscilloscope, greetings.

Awesome little device. As good as you'll ever need, I just don't have a use for it at the moment. Has variable and fixed output. Upgraded metal remote and power supply from Ifi. $175 shipped CONUS price is firm thanks!

U2 - Zooropa
Pink Floyd - Delicate Sound of thunder (next one up)

Is it feasible to make a voltage divider at the input of a tube amp by using the grid leak resistor and another resistor forming a voltage divider to reduce input signal voltage ?
A bandage I suppose for a preamp with a bit too much gain.

As the title says, Hoping to leverage the expertise of this forum to help troubleshoot the Whammy my dad recently built. He's super bummed with a major channel imbalance and has not been successful in correcting it.

Hi all.
I hope this finds everyone well and able to help a desperate non-techie. I've had my Yamaha Stagepas 600bt for 4 years. I'm a solo singer who downloads backing tracks and uses his Samsung phone to play them via a USB C to 2RCA that goes straight to the mixer.
During the last 3 gigs in different venues, the sound (backing music only) has been cutting out. No pops or cracks, just stops playing sound through the speakers.
The mixer limiter (and master volume) is nowhere near max, the mixer itself or power doesn't switch off, the phone doesn't switch off or go to sleep (and the playlist display shows the track as still playing!) The mic is still active too but no sound from the phone coming out of the speakers? Had the same phone/set up for a while and never had the problem before.
The attempt sticking plaster was to turn it off, unplug, replace and go again. It then worked but happened again after about 45 mins. I then wondered if it was overheating so I took it from it's casing in the back of the speaker before the gig, but after 20 minutes, it did it again.

The challenge is that it's happening completely arbitrarily. Sometimes on the very first track, then it might be ok for 30 minutes then cut out in the middle of another track. Last night I played a whole 90 min set without issue and it stopped 30 seconds into my very last song. Because it's so randown, it makes it hard to pinpoint a simple issue. I've set up at home and wiggled and checked cables in the hope i can 'trip' the issue and eliminate a dodgy cable, maybe, but after 2 hrs, still no issue!
I checked the points for dirt or fluff, ordered a new USBC to 2RCA last week in case it was this, (just deducing that the issue looked like it was from the phone to the mixer) but last night the issue came back (with a vengeance). At the start, midway through and right at the end.
As well as being annoying, it's sooo embarrassing. Can anyone help with what might be causing this and how I might be able to fix/prevent without 'contacting Yamaha' or buying new kit? Both of which is could do without.
If you could, I'd be forever indebted.
Many thanks,
Salty.

Hi,

I recently obtained an Apo Diva incl. spare Ribbons.
I should exchange the midrange ribbons. They are severe overstretched and are in bad shape.
In my Diva the midrange is supported with two foam triangles lengthwise.

I rember that I saw a Diva without the foam support on the midrange.

What would be the correct way; with or without foam support? What is factory default?

In my imagination, without support is to be prefered. But I don't know.

I am looking for a couple of these drivers. I just built a pair of speakers that have them and wouldn't mind having some extras. Let me know if you have them and how much you would like.

Thanks!

Mike

From time to time I stumbled across really nice OB / Dipole designs. Usually I just put them in my favorites, but it may be really nice if we have an exhaustive list of OB systems out there.

Post your systems too! Pics and short description.

===

Let me start with this really nice implementation by Perfect8. No spouse frowning here 😀






http://www.perfect8.com

I recently rebuilt a pair of ESL-63s, and printed some 5 degree tilt back feet, but I don't like having the sound beamed up at my ears from close to the floor, so I designed and built some stands using 1"x1" and 1"x2" t-slot. The stands lift the speaker about 350 mm off the floor, and they are sturdy and center the weight so they aren't easy to knock over.



Details and link to CAD file here. Extra bonus: they are high enough that my cat will probably stop using them as a scratching post.

Just got them delivered from the UK. Doing up a Lowther Acousta Enclosure for them pretty soon

Premium Drivers information sheet​

Standard specifications: Many misleading terms have been used to describe the paper preparation of the Lowther diaphragms, doping, age-conditioning, curing, varnishing, etc., leading to discussions & myths around old preparations, similar to the legend of Stradivari’s varnish. There is no magic formula. The standard process, used for many years, is to apply freshly prepared 'special pale' French polish to the made-up cone/voice coil sub-assembly prior to fitting to the motor. This soaks through the paper leaving pure shellac distributed through the paper fibres as the spirits dry. Sugar-like crystals can be seen on the surface of a freshly treated cone. A few months sees a uniform yellowing of the diaphragm due to the reaction of light & air with the shellac. The paper fibres are locked with the shellac to be stiff yet flexible; It is generally accepted that the driver performs optimally after this point, though the foam suspensions co-incidentally loosen up over this period, and this has more of an influence at the early 'break-in' period. Older drivers (pre-Thornton) mostly exhibit a dirty, patchy yellow appearance due to poorly prepared lower grade shellac, which does not cure well over time. Controlling the quality & preparation of the shellac is an all-round long-term improvement, but due to the cleaner appearance, some still think we do not shellac the cones. Standard spec. drivers will continue to be available as usual.

Premium Specifications: The main difference over the standard range is the treatment of the paper. In this process the paper is impregnated with our own in-house formular before cutting, forming & assembling. The 'curing' process is mostly complete by the time the unit is tested & packed, though improvements will still be noticed over the 'break-in' period. The new treatment reacts with the paper fibres differently to the shellac process, resulting in a more stable, consistent & dimensionally accurate cone. The impregnation formular, however, can only be made in small batches in our own workshop and will not scale up to industrial preparation. This limits production to the ‘premium-hand-made' scale,
with the inevitable expense involved. The premium diaphragms are also fitted with the new back centre, replacing the foam standard. The entire set of components is laser-cut, enabling greater control of consistency & accuracy over the die-cut standards. Laser cutting also allows us to make small detail modifications like rounding the points of the 'pips' that hold the voice coil to the inner cone, cut elliptical 'pressure-relief' holes to control the dual cone phase errors, adapt the turned edge of the inner cone to a more suitable paper weight & composition and re-design the assembly relationship of the inner / outer cone / back centre / voice coil - most of which
would have been adopted before, but not possible because of the limitations of the old die cutting. The result of all these adaptations is a diaphragm which excels in all areas, including appearance, with the Lowther logos, radial embossing, and consistency of paper surface & colour. The legendary hand-crafted double-wound speech coil and overall <>10.5g moving mass of the assembly are retained. Foam surround suspension is the same as standard.

Sound: Initially developed for use in the Edilia, testing in all driver models & cabinets showed a marked improvement in all areas. Diaphragms prepared straight-out-of-the box for our most critical 'test bed' - the Lowther-Hegeman with field coils - were received by everyone with amazement; described by various judges as 'game-changer', 'most significant positive step for Lowther in years', 'improvement in all areas of presentation of natural sound'. We are confident that the premium 'upgrade' easily justifies the enhanced price, and all customers are encouraged to hear the difference at our studio showroom. All of our top range handmade cabinets (TP2, Almira/Edilia, LHSR, Audiovector) will be fitted premium regardless of driver type. The premium diaphragms can be fitted to almost all existing Lowthers as an enhanced Re-cone, or LFL trade in.

Premium diaphragms: Key points - Changes / Improvements

Paper gsm weight & fibre type
Laser cutting & CAD design.
Lowther's own paper treatment impregnation process
Inner Cone improved, so:
Enhanced choice of phase plug /centre pole treatment
Aluminum or Silver voice coil
Radial embossing
Logos printed onto cones.
New back centre & assembly
Improvements in quality consistency, appearance, longevity.
Significant improvement in all aspects of sound presentation.​

Click to expand...

I sell this excellent MM preamplifier, with adjustable switching of input capacity. The Actidamp board is 99% fitted with selected premium quality components. On the input are paired j-fet 2SK170BL by TOSHIBA. DC servos are equipped with OPA134PA and OP07CP. Behind the discrete input amplifier are fitted nowadays unmountable originals from SIGNETICS - NE5534. As a bonus I will add the power supply board unmounted, also in red, possibility to mount TALEMA 15VA or 25VA toroid. The product is only for true audiophiles who prefer analog sound. Reason for sale: (I go above - all j-fet discrete MM/MC preamp). Payment in advance on wire transfer or paypal.

Price 150€ incl shipping and tracking

I’ve just watched an interview with the designer at Soulution. He mentioned that they buy-in the “industrial” SMPSs that they use in their latest amp. Does anyone know who the manufacturer is of these SMPS ?

Xmas amp-TDA7293 Chip Amp



I have a working dual mono Xmas amp that I have removed from a hack test chassis. This setup produced very nice audio through my test speakers.

What you will purchase is 1 x IEC/EMI power module, 2 x Antek 3225 toroidal transformers, 1 x SFP soft start module, 2 x All C’s psu modules (27.2K uf per psu), 2 x amp boards w/TDA7293 chips, 2 x RTR SSR speaker protection modules c/w, 2 x low cap psu modules (no charge for low cap psu since hand made).

All the wiring, the 2 inputs, speaker outputs, and all the wiring I disconnected to make a good pic will be included with tape tags to where they should be reconnected.

Asking $350 USD with the transformers, and $250 USD without the transformers, plus shipping. Please see pic below,

Thanks,

Myles

I want to run my design's past the forum as this will be my first tube related build.

First the power supply.
The high voltage section:


Low voltage section:


The full power supply PCB:


____________________________________

Now the preamp design:



First the input is buffed to maintain a constant high input impedance and remain unaffected by the feedback divider that can be changed via potentiometer RV2A.
Simulated THD is nice and low and no sign of obvious problems.

However, I am also considering another design that also looks quite good:


Distortion is slightly higher, but now is almost entirely 2nd harmonic. High impedance can also be had (scale R9) and feedback amount can be changed via R14.

What do you think about this circuit? It seems like it might be worth a try. Do I need and additional protection for J1?
Maybe the first amp circuit if better?

Also what is the best way to switch the bootstrap capacitor in and out as this drastically changes distortion and would be nice to compare while listening.
Any feedback is much appreciated.
I can attach ASC files if anyone is interested.

Hi,
I want to build a bluetooth audio system with an ESP32 + DAC + Class D amplifier. This is the first draft of the project and I would like to discuss it with you before starting real tests, in order to optimize the schematics.

What I would like to discuss in particular is the power supply. The entire assembly will be powered from a 12V voltage source, obviously an SMPS. This voltage goes directly into the power amplifier. Then, the ESP32 module and the DAC must also be powered from the main 12V. And here's the interesting part. I started the power supply chain through a bidirectional LC filter, which must filter in particular the ripple generated by the 5V DC converter on the input, so that it doesn't go into the amplifier. On the converter side, I added dumping with an RC snubber for stability, and on the amplifier side, the dumping is introduced by the amplifier's filter capacitors that have an ESR of 2 x 260mR. The converter drops the voltage from 12V to 4.5V. Then comes another LC filter cell similar to the one on the input, with dumping included. This attenuates by 48 dB at 400kHz (the coverter frequency). From here, it goes into an LDO that powers the ESP32 with 3.3V... And it also goes to the DAC, through an RC filter (since we have low consumption), which increases the attenuation to 83dB, and through a 3.3V LDO that further increases the attenuation to 123 dB ! This is my first attempt at designing LC filters and DC converters, so I need to check it with someone who really knows about this...

What do yoy think ? Is this enough to have a quiet amplifier, without switching interference in the audio band ?

Guys,
Last Friday gig one of my tops just go dull, so I noticed and when in front of the cabinet, I immediately knew what happened, I lost the HF driver.

The tops are :
Yammy DSR112, the plate amp have all the DSP and limiting , so why the driver fail?

Metal fatigue, too low XO point (too much LF power), or just too much power.

Factory DSP suppose to prevent any harm to the drivers!

I saw pics on the net where the diaphragm shattered like this or more.

See the pic

Like 8 months ago the original driver died, at that time it you can see the glue of the coil bubbled and more dark suggesting power failure.

But why? I have seen people who play them with the limiter light stuck on ,
And nothing blow.

Do I have a bad plate amp that is outputting DC or not limiting right?

I'm puzzled.

The acoustics in my new home are horrendous and I have to figure out a way to deal with that, or else find a new hobby.



This is my old place, in San Diego. The main room is really wide and deep and the ceiling is a standard height.



Four years ago, I lived in a tiny condo, and one of my top requirements when I bought a house was a big living room. I had to sell my Gedlee Summas in 2016 because my old condo was way too small for such a big speaker.





The living room in my new place is about as large as the old place, but the ceiling is nearly 30' high. When I bought the place, I had daydreams of a space where there would basically be no 'ceiling bounce' and I thought this room would image like a dream.

Instead: it's an acoustical nightmare.

So many issues with his space:

1) Due to the fact that there's absolute nothing between the speakers and upstairs, you can play music in the living room and it's about as loud upstairs as it is downstairs.

2) Due to the fact that there's nothing between the kitchen and the living room, anything that's going on in the kitchen interferes with the living room. Last night we had guests over and I had to put my chair a meter away from the TV, just so I could watch a show.

3) Every surface in the house is flat and reflective. It's like putting speakers in a warehouse.

So I gotta come up with some way to tame this space, acoustically.

My initial idea was a CBT of Unity horns. The idea that I had, was that you could array a vertical series of Unity horns and get a beamwith that's 30 degrees or less. The idea was that I could listen to music or watch a movie without bugging everyone else in the house. After discussing this on the Facebook group, I came to the conclusion that an array probably isn't ideal. The problem with an array, is that it doesn't control directivity to a low frequency. For instance, an array that is one meter tall will control directivity to about 340hz. But nearly all of the issues that I'm having in this space are at low frequency and ultra low frequency.

For instance, on Monday I was trying to watch "Heat." In the movie, the action sequences are about 20dB louder than the dialog. This creates a catch-22:

* if I lower the volume to accomodate the action sequences, the dialog is completely unintelligible

* if I play the movie at a decent volume level, the action sequences irritate everyone in the house, particularly if people are sleeping. My wife's complained about this, and I've even had guests complain about it. (My guest room is on the opposite side of the house, about as far from the speakers as you can get.)

The obvious solution would be a dedicated home theater in the basement. Which would be great if I lived where homes have a basement. In Nevada, there's exactly one house with a basement, and it's built to withstand a nuclear bomb:

Las Vegas House With Doomsday Bunker for Sale

Although I'll admit that buying a fallout shelter and installing Unity horns in it would be a very Patrick Bateman thing to do, I don't particularly like their decorating choices.

So I have to come up with a plan for this space...

ACA Clone Amp

This ACA clone design by JPS64 is only suited for a maximum 24V psu. The design of the amp board inhibits the Resistor mod that is prevalent in the Pass ACA pcb’s. I have implemented all the capacitor mod’s and whatever resistor mod’s I could according to member Tungsten Audio’s recommendations for the Premium build. I was planning a 24V smps for each amp board.

Included are a set of FQA70N10 MFets for Q1 and IRFP140N Mfets for Q2 for each board.

I also would like to include an H2V1 2019 preamp kit that I received from NP free of charge. This is the complete kit with the J112 fets.


I am asking $60 USD, plus shipping for the 2 ACA clone boards. H2V1 will be included.

Please see pic below,

Thanks,

Myles

I'm working on a Lab Gruppen amp that has multiple damaged components due to shorted outputs. On the list are two ST BYW81P-200 fast recovery rectifier diodes in series. Unfortunately, these are obsolete and I'm looking for a sub. It appears that the MUR1520 would work, even though the specs aren't identical. Could use another set of eyes for confirmation.

https://www.digikey.com/en/products/detail/stmicroelectronics/BYW81P-200/1037819

https://www.digikey.com/en/products/detail/onsemi/MUR1520G/919900

Sold




One set of complete and tested Miro PCM63 DAC.
In my opinion, this is the most direct and best combo implementation of the Miro PCM63 DAC.
Sounds wonderful. It is a full, completed DAC, with a pair of Signetics NE5534 op amp for the IV.

You need +5/-5V and +5/-5V (For DAC VA and VD rails) and +/- 10 ~15V for the IV op amp.

All high quality parts are eg. Nichicon gold caps, Wima film caps etc etc... See the pics.
All parts are BRAND NEW including the PCM63P chips. They are installed for the completion and testing to commission the DAC.
Only the op amp ICs are used parts.

Two types of USB-I2S interface can be stacked via the pin headers on the board.
1. JLSounds i2SoverUSB III FIO or older version
2. York + Reclocker

DAC board alone (what you see in the picture in this first post, without USB-I2S interface) + shipping tracked & registered = Singapore dollars 260
I am only ready to accept Paypal Family and Friends as payment.


More information of this DAC here :
https://electrodac.blogspot.com/p/dac-ad1862-almost-tht-i2s-input-nos-r.html
https://www.diyaudio.com/community/...s-input-nos-r-2r.354078/page-209#post-7049224

Feel free to use this thread to post your DIY efforts.

I'm building some silbury's for A10P's, and I'm getting close to doing the final panels. Because of the way I happened to fit up the front panel and side panel, there's not really a practical way to mock up the speaker with clamps. So I kind of just have to wing it with any dampening material inside the horn. Since I haven't nailed down what amplifier (and thus source impedance) I'm going to be using anyway, I'll need to adjust things. My assumption is I'll leave the interior unreachable channels totally empty.

1) Am I going to be OK with just whatever dampening material I can place in the rear openings? I can reach arm length up to the first bend, and that's about it. Obviously I could reach a little bit behind the driver, but I'm pretty sure those openings are supposed to be kept clear anyway. Anybody have a preference for sheet dampening material I could cut to friction fit if I'm stuffing the open end of the horn at all?

2) Any advice on the overall strategy for tuning the dampening, or a source for further reading? I would need a microphone with flat low frequency response, or do my own calibration with REW outdoors or something, I suppose? But I'm not sure where to start with 'Ok a bump at X frequency means add/remove/shift material.'

Hello everyone.

The PeeCeeBee Preamplifier is here! PCBs will be available via group buys arranged in this thread.

_________________________________

UPDATE October 8 2021: All boards from last batch gone. Entry open for 3rd group buy. Shipping has resumed to most countries.

_________________________________

BOM with parts placement indication uploaded >Here<.

Setup Guide uploaded >Here<

Drill Template uploaded >Here<
_________________________________

Introduction:

It is a fully bipolar transistor based symmetrical "Class-A" push-pull preamplifier with real-time adjustable pure Single Ended harmonic distortion level - from less than 0.001% to over 1% - with second harmonic being predominant in all levels! It also includes its own low noise regulated power supply section on-board, that uses the same transistors used in the active section. It can be used as a very good headphone amplifier for voice coil impedance of 32ohm and above. By using a higher gain than the default +6dB, it can be made to put out 10VPP into 600ohm headphones or upto 25VPP to power-follower type amplifiers.

Description:

The preamplifier consists of two gain segments per channel, one push-pull (PP) and one single ended (SE), preamp output is taken from the PP segment. The PP segment uses low gain with very high global negative feedback and generates a clear replica of the input signal with minuscule THD. The SE segment uses high gain with zero global negative feedback and produces the same signal with massive amounts of low-order THD. The PP segment is directly fed the input signal from the volume control. The SE segment's output is coupled to the feedback node of the PP segment, and the SIG ("Signature") potentiometer controls the input signal to the SE segment. With SIG control set to lowest, the SE segment will contribute almost nothing in the main output due to its high output impedance compared to the feedback node of the PP segment. As we gradually increase the input to the SE segment, its output will present gradually more harmonic content to the feedback node of the PP segment where it will be compared with the feedback signal from the output of PP segment, and the difference between the two signals is presented to preamp's output. Since high amount of harmonic content at high frequencies is often unwelcome, the input to the SE segment can be lowpass filtered with user chosen maximum frequency of interest, so that the high frequency signals can be chosen to contain the least amount of harmonics, and treble definition remains intact.

How it sounds:

It sounds neutral, and it sounds warm, and everything in between! How much neutral or warm depends on how much you want to turn the SIG pot! In my system I have been listening to it from morning to midnight, day after day, with the SIG pot turned towards a low setting during daytime and to a slightly higher setting in the evening.

As expected, in its minimum SIG setting, the sound is extremely clean, with a large soundstage, and in its maximum setting, it is extremely sweet (masked), with a narrow soundstage. In my main system I found the sweet spot to be around 5-10% of the turn when playing music tracks where a lot is going on, and around 45-50% when I am listening to chants or other music types where the music is minimal, calm and relaxed. At near 20% I feel the sound is very balanced, with the right amount of depth and detail I like, along with a touch of that "SE" niceness.

I feel that at the highest and lowest settings the system will have a tendency to become "special case", i.e. in both these extremes it may choose to sound very good with some types of music and not so good with other types, subjectively speaking! You feel the sound is not coming good for the music? Turn it slowly and find a sweet spot. But it is Extremely important that you wait a few minutes after reaching the new setting! Read on to know why.

The design was finished in March! Although the pandemic and subsequent suspension of shipping services delayed everything, I kept listening to the veroboard prototype everyday. And something very interesting and important regarding the SIG control has become clear to me in the last couple months.

The position of the SIG control that suits your taste must be found by spending some time listening in a set position. The potentiometer can be turned without any problem during music playback. But instantly finding out a sweet-spot this way is almost impossible - at that new setting it will sound pretty much the same as the last setting and make you feel like the control is not working, although distortion may have changed by an order of magnitude or more!

This is because our aural perception needs time to notice changes in the level of harmonic content, and significantly more time to make a memory out of it. So it is suggested that the user sets the SIG level to a position and then gives it some time of listening, then changes the setting to another level and repeat the listening. Expect at least a day of listening to find all the sweet spots for your system. I say sweet spot's' because if you listen to multiple types of music, you will almost certainly find one sweet spot for each type. Each listener will have his/her own sweet spots and the speed of finding them will vary, as some listeners have a more acute perception than others. That said, as I mentioned previously, around 20% setting the preamp can sound good for almost all types of music. Links to a collection of the harmonic levels at different output voltage into different load impedances are shared below in the "THD Spectrums" section. Note that there is about 1dB of output signal attenuation when the SIG potentiometer is at its maximum, this doesn't cause any problem during listening.

Side Note: I noticed that the phase of the second harmonic relative to the input signal was easy to manipulate by choosing the polarity of Q7/Q8 transistors (output of SE segment). Since March I have been using an NPN here which was adding negative phase second harmonic to the output. Recently I changed it to PNP and got the positive phase second harmonic. At first it sounded quite different, and felt like the overall definition has increased. It got me excited and I posted a page worth of it >here<, thinking this is the way to move forward with the preamp. But after a couple days of listening it became apparent that the sonic appeal of the system has been lost with the positive phase second harmonic! I could not keep playing it for more than 15 minutes in a go! There is no high-order harmonics present beyond the 4th, but the sound started to feel thin and kind of bitter. Off to the workbench and reverted back to NPN, and the lushness of the output came back! Hence, back to old way (the better sounding way). The NPN actually outputs normal phase second harmonic, but as the SE segment's output is coupled to the feedback node (which is the inverting input of the PP segment), the harmonics get inverted at the output.


_____________________________________



All active devices are commonly available discrete bipolars. The PCB is a bit large, I decided to make it a little more spacious (I received many complaints about how congested my amplifier PCBs are. They're still congested! 🙂 ).

The onboard power supply is comprised of simple dual rail CRC filters followed by regulated capacitance multipliers in Sziklai follower config, powered from a 15V-0-15V/30VA center tapped transformer. There are two pots in the power supply section (VR5,VR6). Using these two pots the rails can be closely matched between +/-12V to +/-14.5V, and each rail can be trimmed individually. Instead of two large reservoir capacitors it uses 32 smaller capacitors, having much better filtering performance and keeping the profile low. Even with 40mA bias per channel I can hear absolutely no hum from the speakers or headphones. The preamp has no audible residual wideband noise, there is virtually zero hiss with headphones or speakers over ear.

Drill template and setup guide are being prepared and will be shared in a few days.

______________________________________

Input Impedance: 67Kohm
Output Impedance: 32ohm

Layout snapshot:


Schematic:

The prototype:


Input-Output delay:

Slew rate:


Harmonic waveform (at 1% THD):


Video Snapshots:

Power Supply Rail Behavior -> Power Supply Rail Behavior
Power On/Off Transient Output -> Power On/Off Transient Output
Clipping Waveform -> Clipping Waveform

THD Spectrums (Peak-to-Peak output, Gain +6dB, 1KHz):

10Kohm load:

500mV - Low SIG, High SIG
1V - Low SIG, High SIG
2V - Low SIG, High SIG
4V - Low SIG, High SIG
8V - Low SIG, High SIG

680ohm load:

1V - Low SIG, High SIG
2V - Low SIG, High SIG
4V - Low SIG, High SIG
8V - Low SIG, High SIG

100ohm load:

500mV - Low SIG, High SIG
1V - Low SIG, High SIG
2V - Low SIG, High SIG
4V - Low SIG, High SIG

-------------------------------------

All the above shared documents and pictures can be availed in a single zip file >Here<.

-------------------------------------




-------------------------------------

The PCBs are 1.6mm FR4 material with 60micron copper, black solder mask, white silkscreen and HASL finish. Dimensions: 170.18mm x 119.38mm.

-------------------------------------


Important information regarding group buy:

>> The PCBs cost USD20 for one unit.
>> International payments are accepted through PayPal only and payments from within India are accepted through bank account transfer/deposit, NEFT, IMPS and UPI.
>> Delay between placing the batch order to PCB plant and delivery of the boards to me will be 20-25 days.
>> Shipping is done for 3-4 packets a day to avoid stagnation at the clearing hubs due to the slow movement of international shipments.

Thanks.
shaan

Hello,

I have bought a used pair of the McCauley 6174 quite some time ago, and did my best to use them in an open baffle configuration (with limited success...).

But now it's time to finally put them where they belong, into a vented box. I use Unibox by Kristian Ougaard for the calculations, the ideal size would be a bit over 500 Liters... but that's a bit more than I can fit! I played around a bit with the values and ended up with a 300 Liter box with 261 Liter internal volume (deducting driver and bracing), tuned to 20 Hz, F3 should be at roughly 30 Hz (if I did this all correctly):



And here is a rendering of what it should end up looking like:



Here the baffle and bracing only:


And I hear some readers screaming "what, OSB?".

Well, to be honest, I have my doubts about that idea now. I just happen to have a bunch of it left-over at the moment. The baffle is cut from an old but nice and strong oak-veneered 3/4" plywood, it's already being glued up to the bracing:



No OSB has been used yet, so still time to re-think. When I read about gluing OSB, I found a few people saying it doesn't glue well with wood glue. One point against using OSB. Further I just think that going through all this effort building the speaker (two, actually), why not spend another 150 Euros and use some Plywood for the rest instead?

I'd love to hear your thoughts on that, and any other thoughts of course as well!

P.S.: The vented port is still missing in the drawings.

I created a shell script, that makes it very easy to install CamillaDSP with GUI and automatic samplerate switching on a piCorePlayer.
Should work on Raspi 2/3/4.
Feel free to try it out at https://github.com/JWahle/piCoreCDSP

Has anyone ever shipped compression drivers to Germany from the USA? When filling out the customs documents, its saying that speakers are a restricted item. I dont understand why, aside from perhaps the solder in them adhering to ROHS standards. Its actually the US customs being picky here, not the EU or Germany.

Anyone else been in this situation?

Hello All!
I bought a copy of Dartzeel. The power supply is strange. It seems to be separate for both channels, but in fact the two bridge rectifiers are connected in parallel and all the capacitors are on both arms for plus and minus.
I want to split the power supply between the two channels like the diagram below. (without the fuses)
Won't the two rectifiers "interfere" with each other?

I have these toroids available. Prices listed are prior to shipping. Shipping within USA and Canada to be discussed via PM. The two AN-3225 in the picture are already sold.

Hi People,

I have been away from audio for over 10 years and its time to jump back in. My last Amplifier was an Audio Note Neiro SE 2A3 .I really liked the sound but Im over desiging high efficeincy speakers. I also have a pair of Old Channel Island Hypex amps and althought they have several sound quality issues, there is something about class D that reminds me of a good tube amp, I know this sounds weird, not sure if others feel this way. I always felt that with improvements, clas D could be world class, are we there yet?

With that said, there are many to chose from, some recommend the Jeff rowland ICE amp, some say that the GAN based amps are amazing, I would love to have some recommendations. I dont really want to go over $5K (3k would be better) but I do want something good. I have been following the adventures of opamp rolling and im also up for that if needed. Would love to hear anyones thoughts.

Thanks

Geoffrey

Warmth Of The Sound - “WOTS LeGrand”.

Very few words to introduce this thrilling preamp: in the listening room of RS Multimedia in Rottofreno (Italy) it gave us goosebumps for the warm softness and ethereal transparency of its sound.

Someone has judged it to be a piano preamp for the accuracy of the reproduction of this noble instrument; others marveled that for the first time they experienced almost the same feeling of attending a live event.

I was standing with a shiver that kept running down my spine.

In another session there were four hidden preamplifiers in comparison on a not really expensive chain but pretentious just enough. The “WOTS LeGrand” was the undisputed winner for expressed musicality, indeed very characteristic but completely devoid of color.

Different thing is to say `Linearity, “Aikido” is on the podium here. But is linearity more important than musicality?

Someone to answer.

I stop here, the schematic speaks for itself. A handful of components ... not so much a "handful", not the components runnning in your drawer, but high quality goods. There would be a lot to say about a simple topology with unconventional configuration, but I will do only is somebody is interested and asks for it.

It was the year 2003. The pictures are related to mine, 2007 build.

You will excuse me if I don't dwell on it, if I don't tell you the philosophy of the project, the various phases of analysis ... The truth is that “WOTS LeGrand” was born as a joke! Just a couple of concepts put together.

The success of this joke was great among my audiophile friends and friends of friends. One of them, dear Franco, who now listens from up there, forced me to design a solid-state version because he didn't like working with tubes. But he asked me that its sound must have been the same. Thus was born the “WOTS Tre”, which we developed together during one whole day to find the polarization with the best sound, the same imprinting of “LeGrand”.

The delay you see in the schematic is mandatory, it shorts the output for a pre-configured time to let the eqipment settle stably.

Simple schematic, impressive sound. You have to try. Oh boy, you have to!

Ted from southeast US. New member going down a rabbit hole when I decided to pull out my old gear from the 80’s. Also picked up some pieces I was never able to get back in the day to complete the set. Shocker…it’s not all working like it used to. I’ve already received a lot of education and help reading threads here and got some things working. I’m stuck on a few so need to turn it up a notch and jump in the DIY Audio pool. Thank you everyone in advance!

(For Mechano24 design with Scan Speak drivers click here LINK)
(For Mechano323 3-way design with AMT driver click here LINK)
(For Mechano23 design with Scan Speak and SB Acoustics drivers click here LINK)
(For Mechano325 7l 3-way design with Dayton drivers in "horizontal" arrangement click here LINK)


Mechano22
Not so long ago, I made a small 2-way speaker design with the following goals: f6 around 40Hz with 8 liters BR enclosure, generally balanced on-axis response and close to linear frequency power response.

Experience gathered with that design led me to a conclusion that maybe it could be done better and cheaper. And here is the new version, codemame "Mechano22".

It is based on relatively inexpensive set from Dayton: ND25FW-4 tweeter with waveguide and DS135-8 midwoofer.

Box dimensions: HxWxD: 290x174x260mm, made of 18mm birch plywood. The Box is filled with polyester fiber.

Both drivers are placed in the middle of the front panel, with centers 75mm (tweeter ) and 195mm (woofer ) from the top edge.

The woofer has a flat basket edge, which, according to the manufacturer's note, allows application without flush so it wasn't implemented. On the other hand, woofer mounting hole was chamfered on the inside.

Pic1. System on-axis and power response characteristics in comparison with target lines. For power response calculation +-180deg measurements were taken in H and V planes (10deg step):




Pic2. frequency response for DS135-8 (orange) and ND25FW-4 (gray):



Pic3. Crossover schematic:


Pic4. VituixCad, schematic and 6-pack for double check:



Pic5. Filters assembled on a scrap of plywood (for 1 unit):


Pic6. Units assembled (need sanding and waxing ):


Pic7. Measured on-axis dBspl (both units, 5dB/div). f6=40Hz if I did not messed up the measurements.


Pic8. Measured system impedance (both units).Nominal impedance is 6R (considering 5R minimum at 200Hz):


List of components used (for one unit):

Dayton Audio DMPC4.3 / 4.3 uF / 5% / 250 V / Polypropylene capacitor MKP
Capacitor Jantzen Audio CrossCap 0.47uF / 400VDC / 5% / MKP /
Dayton Audio DMPC8.2 / 8.2 uF / 5% / 250 V / MKP 2 pcs.
Capacitor Jantzen Audio Cross-Cap 9.1uF / 400VDC / 5% / MKP
Dayton Audio DMPC-2.7 / 2.7 uF / 5% / 250 V / MKP polypropylene capacitor /
Ty-Ohm ceramic resistor 22ohm / 22R0 / 20W 5% SQP
Ty-Ohm ceramic resistor 4.7ohm / 4R7 / 5W 5% SQP
Ty-Ohm ceramic resistor 100ohm / 100R0 / 5W 5% SQP
Ty-Ohm 12ohm / 12R0 / 5W 5% SQP
Jantzen Audio core coil 0.68mH / cylindrical / 0.162ohm / dr.1mm Fe 0.021kg / dia.20, length 40mm /
Jantzen Audio core coil 0.82mH / reel / 0.22ohm / dr 0.8mm Fe 0.056kg / dia.24 length 33mm /
Jantzen Audio Air coil 3.7mH / 3.25ohm / dr 0.5mm / dia.33, length 15mm
Jantzen Audio Air coil 2mH / 3.21ohm / dr 0.4mm / dia.31, length 8mm
Jantzen Audio air coil 0.12mH / 0.26ohm / dr 0.7mm / dia.27 length 8mm

Attached files: VituixCAD *.vxp and XMachina *.xmp with spinorama.

I began a previous thread about what adhesive to use when replacing woofer surrounds to these same speakers which are Technics SBX500. Their woofers are a flat disc instead of a cone.



The surrounds attach to the disc's underside and the original surrounds had an inward roll. I could not find replacement woofer foams actually described as inward roll and I read forum posts stating that to achieve inward roll, one simply inverted a surround.

That seemed simple enough and I thought it made sense.

It took some time to find a vendor with a seemingly compatible surround and they arrived today. Instead of one pair I ordered two in case I botch a first attempt. I had my fingers crossed that they would be a perfect fit when inverted. And they are very, very close to a perfect fit but not quite. There is a slight distortion to the inner circumferance when attempting to fit this way. The only way I can make these foams work is if I install them with the roll facing outward. Based on the dimensions I was able to gleen from the woofers in their present state,, the surrounds I ordered were by far the closest match.

This photo shows the new surround loose layed onto the woofer attempting to show the profile I'd have when installing it as an outie instead of an innie.

This thread is for discussions about any of the chassis. For more information on this product, please see the product page below.

• Chassis Product Pages
• Original Announcement and Request for Feedback

Threads on diyAudio or elsewhere on the internet that show off what can be done with these chassis or give creative ideas:

• List of dimensions for all chassis in one PDF

Hi All,

I’m looking for b1 schematics, can anyone help? Resistor r69 is burnt and possibly one of the output transistors as well, but can’t see the colors. Thanks.

AI, for or against?
I'm one of those who thinks AI should be reserved for important things, like research, basic research, medicine, etc.
Any other use, often futile and out of laziness, drives me crazy!
And what about "images" generated by AI? It's unbearable. For me, who loves photography in general (as someone who looks at things, not takes them), everything in an AI photo is disgusting and disgusting.

I see more and more people using AI to try to troubleshoot or modify one of their devices. I think it's even worse than anything. It's literally separating the head and the hands, and generally, when you separate these two, it doesn't go very well (referring to the headless chicken running around).

This is a DIY forum, I mean, the answer is in the title... and also a place for mutual support and LEARNING, and I'd rather not see this AI thing here. Even for fun, it's an insult to human intelligence and its hundreds of thousands of years of evolution.

I also think that human beings are lazy by nature and will always take the easy way out rather than the hard work, even if the latter allows us to grow and learn.
As proof, relatively speaking, I have people who no longer know how to park their car without assistance, and worse, those who don't know how to park it with assistance.

The "Method" and the "gesture" are things that have been lost for years. AI is accelerating this phenomenon, and I would like it to be banned from this place.
I would like to know what you think.

I was looking for a schematic or service manual of P-300L (problem solved).

Data of the mains transformer alone would be nice also,
because it is burnt.

This is not for the first time a defective transformer is
encountered on Accuphase amps or japanese gear in
general.

The german importer will not provide schematics any
more "because of sole property of Accuphase". This
has been different in the past though.

Thank you for response.

Edit: I can help with diagrams for C240 , C280 , E202 , E204 ,
E303 , E305 , P11 , P266 , P500 as paper copies, maybe
PDF later.

Edit for search engine: C-240 , C-280 , E-202 , E-204 ,
E-303 , E-305 , P-11 , P-266 , P-500

Edit: P-266L schematics in post 25,
C-280 in post 36 , high resolution in post 104
P-500 in 37,
E-303X in 38.
P-300 L see post 67 - 68 69.

Edit: Accuphase P-11 power amp schematic in post 42

C-240 preamp schematic is in post 43.
C - 280V schematic in post 80

M-60 mono power amp service manual see post 44.

E-303 power amp schematic here https://www.diyaudio.com/forums/solid-state/360711-accuphase-303-dc-offset-issue.html#post6362484

Somebody offered Service manual for E-550 Integrated Amp in post 45, see also post 55.

Many Accuphase and other schematics listed here : Schematics – Audio-Circuit [.dk]

More Accuphase manuals, even for service : Accuphase manuals | Hifi Manuals Free: Service Manuals, Owners Manuals, Schematics online for free download .. is this https://www.vintageshifi.com/ now defunct ?

Accuphase P-600 schematic photo is here :
https://www.diyaudio.com/community/threads/accuphase-p600.410952/#post-7644118

A-45 and others see post 92 and 92

Thank you to Kimmo Saunisto for this wonderfull software😛, very very gratefull.
it is very complete and powerfull, but you need to know well loudspeaker design.
Software

thank you again.

I'm the new 'owner' of this amp and it has been in use for several months now. The pre-amp being my Kondo M7, vinyl source and single large Audio Nirvana 15" speaker.?

I am hoping that I can rekindle some interest in this design. The sounds is good and the design is an interesting one because it exploits what is normally a weakness - the charge storage in the base region of the power output devices - to provide a smoother cross-over at h.f.


Anybody else out there still playing with this amp too ?

Hello all
I have fallen in love with the Pearl Acoustic Sibelius but can't afford it.
Is it possible to clone it or build something similar? Please advice

Just throwing this out there in case anybody has an extra pair to spare, I’d love to purchase it. I know it’s a longshot, but I’ve got a project that would be a dream with a pair of these in it. I have a shipping address in Austria, also in Virginia USA

Thank you in advance for your help!

-mac

Anyone ever consider doing a Orangutan clone?
What drivers would you use?
Looks like the SEAS 10", but that only states as 89db.
The Orangutans are 93 & 96 db
Any thoughts?
Thanks
Mike

Curious if anyone has experience with or measurements of the Audax TW025A28 or TW025A20? The gold one sounds like it simply a gold plated titanium version of the regular titanium, but the response plots are quite different. And they look different measurement systems at different times, so I'm wondering if that is why they are so different?

good morning everyone I have these sprague they are very big 65 mm diameter 105 mm height they could be good for the aleph 5 power supply I have 24 pieces thanks

Hi guys, as tittle said "Building BA-3 as analog output stage of noDac", well the noDac outputs 0,19Vrms so I was looking for something with a gain x10 to get near the standard 2Vrms, helping me to take the BA-3 option because I own original SK170BL, SJ74BL, K2013 & J313 from when I used Erno Borbely stuff, also it's not complicated to do it and adjust (very similar to Borbely), don't take to much room inside noDac box and is a lot of more easy and a lot of less money than make a DHT 4P1L with the same gain of course I don't expect the same SQ.

I read with attention NP BA-3 article, it seems with standard resistors values BA-3 fits nicely the x10 gain I'm looking for.

Attached NP BA-3 article to know if it's the latest or there is other new and also B.O.M. for a balanced unit that I will not do because all my system is SE.

I read Jfets have to be "matched if possible" at 10mA Idss, I have on hand:

SK170BL
9.48mA x 2

SJ74BL
9.02mA x 1
9.03mA x 1
or
10.11mA x 1
10.24mA x 1
What's best pair to use with the SK170BL?

I guess with these values P1 & P2 will remain 500R, right?

With the input voltage of +-25V can reach the x10 gain?

I will post pics of my work in progress.

TIA
Felipe

N.B. Big thanks to Jim aka 6L6 to give me a couple of PCB.

As the beloved SSLV1.1 BiB shunt reg was getting long in the tooth, especially for NOS JFETS, I had in mind for some time now to design its successor. The goals were: 1. In production parts 2. Much simpler to set up. 3. Better technical and subjective performance.

After many breadboard experiments and two prototype PCB iterations I feel that my goals were finally met. So here comes the UltraBiB V1.3 😀

-Uses no NOS parts.
-Can do 5V to 40V output without changing a thing in its parts configuration.
-Nothing to choose and match. No tolerances in predicting its CCS limit setting.
-Has 45dB more open loop gain and many times less output impedance than 1.1
-Sounds easily better.
-Its an electrically and mechanically drop in replacement for an upgrade from 1.1

I have already given spare earlier proto boards with now deleted experimental features to few local beta testers. They are all happy by now as far as I know. The pictured board in green is the final layout in just cheapo proto that's a pain to rework and its pads vaporize in the end. It will come in proper grade black solder mask and immersion gold three sections board just like the original.

Attached: Zout plot for 150ma spare current and noise plots for 100,150,220,330,470,1000uF C2 (red 220uF). Also the rails probed on the scope for positive and negative sections. Here are typical values schematics also. I will write a PDF with instructions. Not that there is something truly special to consider when building it with the suggested parts but to describe it better as an item and to clarify details and precautions.

Updates:
31/5/18 R9's value update
1/6/18 OL sim at 100mA spare
2/6/18 Build Guide PDF added (0V0b)
24/5/19 Triplet board dimensions picture
21/6/19 The PF5102 JFET became EOL. But GB long term supply is secure. For substituting with J113 see info in post #1559
15/5/20 BC560C became EOL. But Group Buy long term supply is secure. BC559 can be used up to 30V output. BC556 for 31V-45V output.
2/7/23 LNA instrumentation measured a very low 2nVrtHz spectral noise density from the UltraBiB under real working conditions. post#3,688

Hello everyone,
It’s been a long time since I last returned to the forum. Over the years, I’ve been quietly experimenting — trying, failing, and trying again — and have completed several DIY audio projects, from DACs and amplifiers to power filters.
Now, I’d like to share some of these results with fellow DIY enthusiasts, so we can learn, exchange, and connect through our shared passion.


Today, I’m introducing the DAC-End 24, one of my most cherished projects. This is a No Oversampling (NOS) DAC using the AD1865N-K chip — the same chip used throughout Audio Note’s product line, known for its natural, detailed, and uncolored sound.

---

🔧 Key features:
– No oversampling, no digital filter → natural, honest sound
– Passive I/V stage for clean and detailed audio
– Individual LT3042 power regulation for each section → ultra-low noise
– Integrated Amanero USB interface, supports PCM 24bit / 192kHz
– 4 selectable inputs: USB I2S, SPDIF RCA, AES/EBU, Toslink
– Compatible with SRPP or single-ended tube output stages to reach 2Vrms
– Compact, well-isolated layout, easy to DIY and upgrade


👉 Feel free to leave a comment or message me directly if you're interested.


– Quanghao

Help me with Schematik service radio cassete
japan Crown CD-300 pls!

For sale various transformers,

2 x O core 230 V 100 VA 2X 15V James transformer (one potted) 35 Euros each.

1 X R Core 230 V 30VA 1X12V 2,5 A 25 Euros

1 X R Core 230 V 30VA 1X7,5V 4 A 25 Euros

Проект RM-6.
Начало

{
Update:
please jump directly to the end!
}


The day before yesterday I stumbled across an article by L. Stellema (University of Sydney, Department of Aeronautical Engineering & Electrical Engineering).
Published in September 1980, it's a pretty well-designed hi-fi amplifier with impressive specifications.

in advance
the final stage of the small, clever amplifier - All transistors are mounted on a common heat sink!

Hello,

I'm working on a device that needs to switch between two AES3 audio channels. For this purpose, I’m considering using the TS5A22362 analog multiplexer.

According to the datasheet, the TS5A22362 supports up to 5.5 Vpp signals, while AES3 signals are typically defined as 2–7 Vpp. Given this, is it still a good idea to use this part, or would you recommend a different solution? If it is fine, should i supply 5V to VDD for the best performance? Will this design be reliable for all types of audio equipment?

I’ve also heard that using relays with gold-plated contacts might offer better performance in terms of jitter. Could you please advise on this?

- We many times wonder what if that SMPS brick that feeds the Raspberry Pi or the mini PC or the MiniDSP or the Squeezebox or the DAC or the desktop Class-D amp etc. was a linear PSU? How such wonder boxes would perform without switching noise polluting their rail and most crucially their many times interconnected ground?

- What if we had a simple and strong linear PSU instead of fixed SMPS brick adapters that it could cover the voltage range for such applications by only setting it up with a jumper?

- Enter the L-Adapter. A versatile Sziklai pair stabilizer / capacitance multiplier based on LED voltage reference.

- Its output voltage is how many LED + trimmer minus one Vbe. Roughly 1.5V to 20V range. Move the jumper, trim Vout, ready. Connect the load.

- Is it any good? Yes its good. Not noisy at all and stable. For 1.5V input ripple it produces 1.5mV thick DC line. For 3 Ampere load it measures 0.02Ω output impedance. Which is flat and extended in frequency. When you pulse it the recovery is clean of ringing. Because there is no feedback between the output and the voltage reference. We want a general purpose PSU staying insensitive to random gear loading peculiarities.

- The recipe isn't anything new but the details are well researched. Low noise unity gain reference, but adjustable too. Which LED bar with which CCS experimentally chosen between many styles for very good Vref stability, what pair of transistors, the layout. Various ways to sink it, accepts quality TO-220 bridge diodes, two reservoir capacitors, fused like a Π filter. The board is 136mm x 63mm.

- What about its output current ability? Well, it uses a 15A audio amp grade TO-3P pass transistor. But that alone says nothing much. Its also the transformer the diodes the reservoirs the sinking the load's average consumption. Say up to 7.5A average can be catered for.

- For any light or heavy current application it takes that the chosen Tx the bridge diodes and the reservoir caps won't lose the plot for a target Vout. That's about rectification and filtering basics. It does not like less than 2.5V input-output voltage difference. That's the DC difference between C4 and the output. Can probe that between the fuse and V+ out. Or across D11. Although it keeps working on smaller differences it gets progressively goofy. If you see the LEDs dimming a bit its tell tale you crossed the raw DC section's losses good limit.

- Here is a schematic with typical reservoir caps values and some pictures. That soldering iron pulled 55W peak from the mains through the PSU to boot and idled at 12W. The scope pic displays Vin ripple on C4 vs Vout status captured at a point when the iron was still pulling hard to heat up started from room temperature cold state.

The Fluke reads C4's raw DC level in another picture. Started at 27V idle with worst loss of 4V during the soldering iron's boot cycle (trafo, diodes, rippleV). At 23V raw DC for 18V output to the iron, that trafo and reservoir caps passed the 2.5V Vin-Vout criterion by double margin. Other type & quality trafo or diodes could lose more or less steam of course. Higher value reservoir caps would achieve less ripple voltage but would also make the diodes work harder. Since the worst raw DC level sufficed, better not increase the caps value in this case.

The example has 4xMUR860 & 2x4700uF/35V B41231 EPCOS/TDK. Also a 38mm tall Q2's sink. Which sufficed due to the irregular current pull of the micro controlled soldering iron. Can it do an RPi3? Yes I tested it with Wi-Fi and streaming vids on the Raspbian OS. Can it do a 12V Windows 10 Cherry Trail mini PC? Yes I tested it. Watched a whole movie stored in a mechanical 2.5 inch USB Hard Disk attached to it. The PC was at the same time charging an OnePlus X phone from a spare USB output so I pushed it further. I now used lower voltage and smaller size transformers than that R-Core. EI or toroidal of average quality. They and the sinks sufficed again because of the irregular current pull of computers with idling gap periods. 45C on the 38mm 35C on the 25mm ones for the diodes. Minimal RPi use shouldn't need diode sinks at all.

- In the final black & gold boards there are correct Q1 Q2 designations. On the green prototype first photo you may spot Q3 Q4 relic prints, please ignore. PCB size is 136mmX63mmX2mm. Its mounting holes diameter is 3.6mm. Their horizontal center to center distance is 127mm. Their vertical center to center distance is 54mm.

- I will be editing & enhancing post #1 in later installments.

- 25/6/2019 Build guide added (includes circuit description & BOM) - attachments rearranged

Hi there all,
Call me old & rusty [true] but I've only just become aware of Sziklai pair transistor arrangements.
I am hoping that with this Thread I can read and learn more about them.
Any/all info. would be great.

A few years ago Destroyer X (with Hugh's permission) published the conceptual schematic of one of Hugh's commercial AKSA 55 kitset products.

Here is the thread for reference:
http://www.diyaudio.com/forums/ever...ugh-thinking-let-us-see-schematics-forum.html

I was learning EAGLE at the time so I drew the schematic and designed a PCB as an exercise. At the time the AKSA 55 was still a commercial product, so I didn't think it was appropriate to publish the PCB. But now, the AKSA 55 is no longer for sale, so I sent the PCB files off to a PCB manufacturer and have now built a few of these amplifiers.

My schematic is a little different from the one that was shown in the reference thread in a couple of ways. I changed a couple of values that were obviously wrong, I used BD139 / BD140 as drivers and I used a BD139 for the VAS. When testing the PCBs I used the recommended transistors mentioned in the quote below.

Here is a quote from Destroyer X's original thread:

• Differential transistors (Q1, Q2) are matched 2N5401
• Voltage bias multiplier (Q4) can use BD139
• Voltage amplifier (Q3) can not inform, a lot of them works there (I used a KSA3505)
• Drivers (Q5, Q6) are 2SC4793 and 2SA1837
• Output (Q7, Q8) are 2SC5200 and 2SA1943
• VBE multiplier transistor (Q4) can be mounted over 2SC5200 (Q7)
• Bias is 50 mA, and re-adjust again some minutes after first adjustment
• 100 Ohms resistor connected to Voltage Amplifier transistor is a trimpot, small variable potentiometer
• If you do not reach the bias current, change R12 value
• Voltage is plus and minus 36 Volts and power will be 55 Watts RMS over 8 ohms with 0.65 Volts RMS input.
  

Click to expand...

I have actually built one amplifier using BD139 / BD140 transistors and will report on that at a latter date.

I searched the diyAudio site for any reference to the 1 inch screw on JBL PTB99HF-1 Waveguide. 6 inches square. 90 x 90 degrees.

I came up empty.

Anyone use it in a project. Listen to it or have anything to say.

I am thinking of possibly applying it as the top end in a bookshelf.

I have a pair plus a pair of JBL 2408H-2 compression drivers to test drive.

I will post some measurements if there is an interest.

Thanks DT

Hello guys, I wanted to share my last build, maybe get some feedback.

I was very happy with my nupole (nude dipole on a pole).
Took the dipole path few years ago, for a very evolutive and iterative process with 20+ versions.
The last one was very very satisfying, but I couldn't stop thinking that it might all be based on biases that evolved in parallel.
Friends and even more Hifi enlighten friends enjoyed it too but could not invalidate my choices.
Also the room evolved with the build, and I know this could hurt the end result, or know that I might have to change few things to better work with a box system, but this is for later.

So I decided to try one last time a boxed system.
I initially started with a simple 3 way sealed, classic look that I like, reasonable size as I thought I wouldn't need much SPL.
First prototype was not very pleasant.
Build a second one a little bigger, not much better.
It felt weak, not enough presence in the room, no filling/no feeling.
I'm sure it could have been better with a lot of tune work but it was just not a good enough starting point.

So, for the time and money involved why not go nuts with the biggest I could fit in the room?
Always love the jbl 4350 serie, so this was the first inspiration.
And really love the Pitt & Giblin stuff, this was the kick in the back I needed to decide for a 3 way sealed with horns.

In the same time Nicolas opened his online shop on Audio Horn so after discussion I went with the X-28 with roundover option.
2x15" woofer sealed for the bottom to try sub-less first, and allow a future port if needed.
Studied a bit what kind of woofers could play nice in a sealed box of 100L, at reasonable prices, and went for the SB 15OB350 (very cheap and the simulated response was not much better with the 15SW800).
Then what kind of midrange could play nice between 200-1500Hz with this horn? The PHL3040 seemed a good fit, among others.
I could have gone with a more low midrange oriented one but wanted to try.


Construction was fun, I'm very impatient and usually start with minimal plans, my way to deal with surprises during the process.
Very useful informations were found online around the jbl : plans, clones, video build etc so I had a good idea how to do it.
I also have a limited wood work knowledge, practice and tools, so I again went the ikea route, for a good enough finish with minimal work.
So I took some door panels, full particle boards with a fake but nice walnut finish, for the outer box, and Eket boxes resized for the horns.
22mm plywood for front and back, with mdf as second layer where needed + bracing.
100x70x40cm, 280L outside and around 220-230L inside, with a 15L. box for the midrange, bracing very similar to the the jbl, all panels in their longer length + support around the woofers. Kind of light bracing as a start, that could evolve if needed.

Bought few tools to get a nicer result, a little router that was very easy to manage and surprisingly strong enough for the big holes, and a plunge saw with rails for better cuts as my regular circular one didn't cut straight on longer runs.

I've built one at a time and was ready for 3 thinking I will mess the 1st too much, but fortunately it was ok and I was able to do 2 very similar in a row. The second one is a little cleaner on edge cuts and details but is 95% the same I'd say.
To do better I would have to study real wood working, or ask for help.
It sure could be built better but it is solid, where I thought it seemed a little weak I would just add some wood.
If I redo one I would go even bigger as finally their size is fine.

Few pics of the boxes:








And some of last rew stuff:

- Nearfield response per driver, no eq needed on the midrange, big +12db boost on the woofers.
Did a bunch of off-axis measurement to get a feeling of the response, not shared here I just don't always save them and almost never "tag" them anyway.
Planned for a 1200ish Hz crossover for the horn, but surprisingly the 10" midrange off axis response was too good high up, or not enough directive if I can say to get a good match with the horn, so went with 1400Hz.




- Sum and timing made at listening point with mic and ears, before and after eq with averages:




I first heavily stuffed them but at the end removed everything. Clearly lost 4-5db with stuff above 50hz for just a little more low end.
And without, compensated by eq, it just sounds better.
I didin't notice much resonance, nor saw any in the impedance sweeps, just something to check for later.
Still working on the tuning of course, the first result was disappointing on the low end, I clearly missed the clarity of the dipole stuff.
It really felt like I missed some notes! Or the room just ate them.
I tried to integrate the H-frame subs, but this was nearly impossible, placement and room interaction just didn't work to mix both types.

I don't listen super loud so I have headroom with the woofers, that's why I pushed them a lot.
And after few more tunes it got better, I was able to get back some of the presence the first octave can give you.
But sure the room is not forgiving, work in progress…

The horn is really good, of course it gave me more precision in the soundstage, more than the dipole.
So a little more accurate, easier on listening window too, but also less ambiance. It's just too early to judge.
Nothing to say on the midrange, it does its job perfectly, and very efficient too.
They might not be as good as the kartesian, but here it's also too early to judge.
It's the very beginning and there's a lot more to do and test. different crossover points, different slopes etc.
The target is hard to adjust, I need more time as it's a very different result.
Also one day I might measure them outside and try Virtuix, but they're damn heavy…


I re-used the flex 8 and some of previous amps at first.
A Schiit rekkr for the horns, perfect, absolutely silent!
A fosi v3 stereo with 36v for the midrange, lowered the volume but it's still a little hissy.
And Crown xls 1502 for the woofers since the boost needs some power.

I initially though about getting some plate amps, fusion maybe for an integrated look, and to get power for the woofers.
But I also had not so good experience with hypex and HE drivers, so I first took some voltage measurements on the cones to see what kind of power they used.

• dual parallel woofers, 3.6 ohms at 30hz where EQ boost is severe: at -20db on flex, 2.8 watts and at -10db, where I just almost never go: 28 watts. So far off the Xmax limit around 500w even at max volume.
• midrange at 1Khz, peak of the response: -20db 0.025 watts, -10db 0.25 watts

Very efficient, so finally and since I don't think I'll ever go over -6db I ordered a second rekkr to put on the midranges, I'm confident they will be then totally silent.
For the woofers the xls is too noisy, tried the little fosi v3 with 48v and it's better, but I think their new v3 mono will be a better match, waiting for them now. Glad I didn't ordered the fusions!


So now I enjoy the new sound, it's different, but the more I tune the closer it gets.
I don't think I will get he clarity of the dipole, but I will just have to decide it I can accept the new compromise.
If ok I will then finish them a little better, paint the baffle, adjust few things, and then start to adapt the room, relocating the diffusors for example.
If convinced I could even rebuild them better, bigger.
One thing for sure, they will be easier to live with as I don't have big powerplants in the middle of the room anymore, better when receiving a bunch of people during summer.
Cats enjoyed them too, they don't care about the cones and I'm glad, just two more big things to climb on and chill 😉

The Keele CBT uses a curved cabinet.


The JBL CBT does not.

I have another thread on a car audio forum where I'm doing a build on my car. And a member raised the idea of doing the delay passively, like JBL does. (his post is here : Car Audio | DiyMobileAudio.com | Car Stereo Forum - View Single Post - 28 Weeks Later )

So I wanted to explore ways to do this but wanted to do it in a separate thread, since the CBT has been discussed more here than there

Hey Folks.

I'm a person behind hardware projects under the Sonocotta name. I'm a big fan of DIY audio, most interested in digital hardware projects, based on ESP32 and Raspberry Pi. I did a few projects with other SBCs and microcontrollers, but currently focusing mostly on those two.

I have had a passion for audio projects as long as I can remember, and now I think it is the best time for it, with so many possibilities opening with new, ever-so-affordable silicon, information available under an open source badge, and all the community built around it.

I am keen to communicate, participate, learn myself and teach others. Reach out if you believe I can be of help.

There is a recently applied patent that takes another very different look at making an electrostatic loudspeaker. Particularly the way the stators are made.
I contacted the patent holder and asked if it was OK to give a DIY approach on his design a go. As long as I was not promoting it commercially he was OK with it.

So here is a short video of the very open design as a proof of concept. Yes it works and it works fine.
Sensitivity is very acceptable, distortion is low, but what is most remarkable and I don't know of any way of measuring that, is how OPEN is sounds. That was also most likely the intention of the design in the first place.
The designer claims a complete break on the relation between open area and capacitance, but that is, sorry to say, not true. There is a fixed relation between the two, but obstructions area is much smaller than with wire or PCB stators.

Took several days of 3D printing the 500+ parts that are in there and several weeks of manual labour to apply and assemble the whole contraption.

Per panel the square space is like a Quad ESL-63 panel. Eventually we want to try and build a complete speaker with 4 of these panels each. The ultimate goal would be to apply the delay rings as well.

Panel size Mylar surface 58x17 cm. That is 98.600 mm2 of surface area.
Obstruction surface is only 18.300 mm2, only 18,5%.
Open surface remaining is a whopping .... well you can see it in the short video.
Stator to stator capacitance is 90 pF.
Diaphragm movement space twice 2,5 mm (also like the Quad-63 panel)

Please note that this is a patented design and done here just for the fun of proving that it can be made with simple means and to have a listen at the characteristics without having to travel half the world to hear the original concept. There are still a lot of thoughts on how to change/improve upon what is demonstrated here.

In the full range and multiway forums there are threads dedicated to pictures and stickied to the top but not this one. With the variety of different subwoofer design options it seems like a pictures thread could be interesting. I for one would love to see everyone's subs in one place

Maybe the mods could chime in on this one


(Mod note: Thread now in place as requested)

Is there a source for cores so we can wind our own woofer crossover coils?
What might be the performance difference between the laminated steel cores versus powdered iron drum cores (pictured below)?

It does not have the "Philips" logo on it, is this real?

Please help

hello,

it's Andrea here, long time lurker and appreciating a lot this community. this is my first post, just registered to signal a China board i've not seen described here.

of course, i've not any economic interest in the vendor. i've just ordered one sample to check the quality because it looks like a compelling price! 🙂 i don't' know what to expect..

i tried to find schematic info and demo project but nothing to be seen.. have you ever heard about this stuff?

bests

andrea

I need some help to identify the inductor value in my Dali spektor 1 crossover circuit.
Also I like to know order/type of the crossover would also be appreciated?I will attach some pics of the crossover.Any help is appreciated 👍

Hello All,
Due to lifestyle changes and some elderly age conditions, I have come to the realization that I will not be able to complete building my inventory of amps, dacs, preamps, etc. So to start things off I have the following items for sale.

I have built the boards to be a dual mono VH4 with completed Rev1 & Rev2 mods. The module pics are attached below. I am only charging for the big ticket items, so, the price per module is 90 usd. These pcbs have not been powered.

Thanks,
MM

Hello all,

As impressed as I was from the subjective performance of my recent low voltage shunts for my NJFET RIAA (link), I developed high voltage ones for my tube gear too. The first test has been done powering the Steve Bench cascode 12AY7 parallel & 6DJ8 RIAA. A phono circuit is the most sensitive one so to fully test a reg PSU IMHO. The previous reg was a Mosfet Maida. In brief: 1. Lower noise than with the Maida, in CDP background silence territory now. 2. Bass definition and slam, image focus, image size, mid and high smoothness, one class higher with the Mosfet shunt. Maybe a 25% overall subjective performance lift above the Mosfet Maida.

Read the high voltage safety sticky thread if not familiar with tubes and tube supplies practices. A useful reminder for experts even:
Safety practices for high voltage

Updates not to search in a long thread:
SSHV1 Standard
SSHV2
Troubleshooting example