These kind of potentiometer are use in a lot of mixer console.... but these pot are good for HI-FI audio ???

Somebody tried it ?

Saligny Power 1 piece

I built myself a BB3 phonostage, initially in a relatively small box, but suffered a bit of hum from time to time.
Recently, I decided to rehouse it into a bigger case, which is pretty much finished now - see below.

I am wondering if there would be any benefit from fitting a 5mm thick aluminium “shield” Between the BB3 PCB and the mains related side of the case. It will not be expensive to do, or take long, but will there be any benefit?

It was suggested to me to start a thread regarding the actual practical builds of horns and waveguides, mainly designed with the Ath. So here it is, for everyone to share their own way of converting their design into something real and listenable. Show off! 🙂

So far the tool can generate:
- STL file,
- coordinates files to be imported into Autodesk Fusion 360 as splines and/or smooth surfaces.

There may be other useful features implemented in to tool to enhance the practical possibilities - just let me know.

this is the anniversary of almost succumbing to hypothermia on the the side of HWY 11 in northern Ontario while on tour...

I have a Rockford Fosgate Prime R750-1D good blue led, no sound.
The only thing getting hot/warm is the Led, 494 and the 1GM transistor beside it. (picture)
None are over heating just around 96-98. Any help wound be appreciated.

Thanks

Hello everyone,

I am looking for a copy of the schematic of the Sugden A48B , early to mid 90's version with horizontal fins heatsink on each side.

Mine has just developped a heavy waterfall noise. I am alrready suspecting a PS problem but would like to refer to proper data before diving deeper.

Thanks to anyone able to help .

I bought an AD5933 eval board some time back to facilitate measuring capacitors and inductors. I just got around to actually fooling around with it (using an Arduino Uno) and initially had some problems. While the calibration procedure seemed to work OK (I used a 100K resistor for that), results for different-value resistors and capacitors were WAY off. I thought there was a problem with the driver code, which I downloaded from github. I thought perhaps there was a problem with the board, like a cold solder joint.

But it turns out that the code and board are OK. The main problem was that I was using the maximum-gain setting for the input amplifier so the AD5933's ADC was overloaded.

Once I figured that out I was able to get much-more believable resistor and capacitor measurements. In turn, I measured the capacitance of my headphone cable, to build a load tester for DIY headphone amplifiers. 200pF will do it!

I just recently checked ebay to see what the current prices are for an AD5933 eval board. I found some in the $30-$40 range. However, for about the same price you now can buy a "component tester" that can test R's, L's and C's, but you also get the ability to test some active devices, too. So while the AD5933 eval board is a nice thing to have, i probably would have bought a component tester had that class of tool been available at the time.

I have 3 Uni-q drivers for sale.
They are all working.
I used them in custom surrounds.
Looking to get 300
Buyer pays shipping and paypal fees

Hello,
I recently purchased this small NVArcher BP1048 DSP Board.
It worked fine for the first two days, but when I came back the next day and turned it on, the output was extremely quiet. So quiet that it took me a while to realize it was even running. I did not make any changes in the software.

After opening the ACP Workbench software to see if any volume sliders where turned down, everything seemed to be fine. All the volume slider where roughly at +-0dB. I had to increase one of the volume sliders (PGA0 - Line_in_4_5) to +40dB (!) to get any proper output volume, but obviously this distorts the sound like crazy and still was not very loud.

I turned all of the "Audio Effects" off, to make sure I did not mess anything up there.
The board itself is running and the problem is the same in both AUX and USB Input mode. Also the same on both outputs DAC0 and DAC1. I tried using different input devices, different cables and different amplifiers, but the problem is always the same. As soon as I plug the DSP inbetween, it is extremely quiet.
I played around with selecting and unselecting a few things and experimented with some sliders, but without success. I tried to reset it to factory settings, but I feel like this did not reset anything. Visually I can not see any damages on the PCB itself.

Am I missing something? It seems weird to me, that it worked fine at first and instead of completely dying, it still runs, just extremely quiet.

I am regretfully selling an incomplete project of a Lii Song Leonidas build. This follows Leon Huijgen's plans from the Audio Dandy Website.
It includes Lii Song Crossovers, a pair of Silver 10 + a pair of W-15 drivers
Too heavy and awkward to post.
Pick up from Australia 3134.
$1400 or nearest offer.

I've been looking for a service manual for the Marantz SA14S1 so I can figure out the output impedance(I've got a picky tube pre-amp which doesn't like anything over 200ohms single ended).

The above website is the only one I've found which has it available but the site seems kind of shady and they want a lot of personal information before letting you download the .PDF.

I found a manual for the SA15S1 but I can't confirm if it's the same design or not. I'm not sure if I'm reading it correctly but it looks like the output impedance is going to be 100ohm for the single ended outputs?

Thanks for your time!

Olá a todos.

Eu tenho um Zapco Z100c2, acho que era das primeiras versões, faltavam esses capacitores de cerâmica no pré, alguém sabe o valor original deles?

C20,21
C27,28
C30,31
C32.33

PRICE REDUCTION


Literally downsizing.

These originally drove my Tuba HT subs.

Pair of used Lambda TD-15x drivers available in Massachusetts, USA.

Currently mounted in TOA EV monitors (free if wanted at asking price)

$600 includes domestic shipping to contiguous 48 States.

Will ship to any verified PayPal address for actual freight costs.

I have a pair of metranome 3s by dick sequerra, km looking for the mid range speakers for the pyramid met 3s, it looks something like this.
Any opinions are welcome thank you!

Hi, Passionate about audio systems, still in learning, there is no better opportunity than being able to design and build the electroacoustic instrument that will play our favorite notes.

Audiospeak Dictionaries....suggestions requested

From stereophile, most used adjectives:

eponymous: name on the box is name on the gear
black: absence of white

Looking at some LT3042+transistor power supply on ebay, the transistor being used is D45VH10, and is specified that the max current output is 1A, is there a reason it can't do more?

Hello forum members,
I am new to this forum, but I already have quite some experience in building speaker boxes.
I now have three rooms to be equipped with 5.1 home cinema speakers, although the main "payload" is gonna be music.
Because of high cost associated with I decided to build the speakers myself. I need the speaker boxes to be universal enough to accommodate a few different drivers.
My choice for cabinets is: Troels Gravesen Ekta TL http://www.troelsgravesen.dk/Ekta-TL.htm for front speakers and
STUDIO-101-mkII http://www.troelsgravesen.dk/STUDIO-101-mkII.htm for rear speakers.
But I wanna make it clear that this is just a guidance for the construction/shape/size of the speaker boxes. It is not my intention to copy those designs.
So what do I want to make?
I like those designs of Troels, but the speaker drivers he uses are way out of my budget. So I am looking for cheap replacements.
But I like the concept of the boxes. His Ekta TL can be adopted as bass-reflex, TL can be shorten or extended easily.
So, I need a your suggestion of what cheaper drivers can be used in those cabinets. I can make some adjustments to the cabinets to accommodate other types of drivers. No problem. But I want the genera concept to remain the same. TL for the front speakers and BR for rear speakers, full bandwidth for both.
So for Ekta TL my initial choice is:
-SB20PFCR30-8, https://sbacoustics.com/product/8-sb20pfcr30-8-paper/ , the same fs as the speaker in original design, so no mods to the cabinet are necessary,
- mid range?
-DT-300 from Monacor, https://www.monacor.com/products/akcesoria--/glosniki--/glosniki-wysokotonowe-hifi-/dt-300/

For STUDIO-101-mkII:

• sub-mid range ?
• DT-300 from Monacor

I consider those two speakers as good enough quality for the money, and good enough for me. In Europe all those drivers are available for more or less 50 Euro. And I would set the budget for the speakers in that range, plus minus a few euros. I already build some speakers with SB20PFCR30-8 and I consider it a very good driver for the price. Very good. But I am open for suggestions here.

The requirements are (for both front and rear):

• absolute minimum driver sensitivity 90 dB (no compromise on that),
• bass as low as possible,
• the size and volume of Ekta TL are just about right for me, but I can adopt it a bit for the driver
• rear box volume can be up to about about 30 litres, 2-way, sensitivity min 90 dB, good bass.

Can you suggest some good budgetary drivers that have good sensitivity and can fit in the cabinets mentioned?
As I said, the Troels designs are given just to give you some idea of what I want to build.
I still need an idea for a central speaker. I want it also to be full bandwidth with 8" woofers.

Wiim Pro power supply (can be used for anything that has same requirements, just make sure you don't go above 3A), USB type C and aux pads for DC barrel. Also led pads for pilot light (marked with a dot for anode, not seen in pictures but its on gerber). Based on AmyAlice , but modified to be a separate psu on it's own. It uses Mean Well IRM-20-5 smps can be used with others of the same footprint, and two connectors with pitch of 5mm (or solder directly preferably). Rest is the same BOM as og. Already built and tested as seen below. As good as it gets regarding smps supplies.
Enjoy.

This preamp is dht output.german pentode in first stage .tube + mosfet in power supplay. pentode+triode in active riaa phono .

Excellent receiver
No issues. Comes with manual and learning remote
Weighs 30 lbs
Shipping from 95453
$200 plus shipping

We've been discussing copyright issues in other threads that all appear to be closed.
But I read an interesting report today that throws (at least for me) another light on the issue.
A court here in Amsterdam issued a verdict in a case where two parties claimed copyright to a specific design.
The judge ruled that for that specific design, no copyright could be claimed by either party. Why?
The design choices made were based on functional and technical factors. None of the design dicisions were based on any form of creativity.

If I translate that, it would mean that if you design say an opamp stage, you cannot claim copyright on the circuit unless that circuit has creative design decisions.
The values of resistors and capacitors, and their arrangement to get a stage with x gain and b bandwidth are functional and technical and do not warrant copyright protection in themselves.
You must have design decisions/arrangements where those knowledgable in the art are surprised and agree it is novel/creative.

For me it seems that some of the patent criteria seep through into copyright territory.
This was just one judge but it does establish a precedent.

Jan

Excellent condition as seen in pictures. No issues, just don’t use it anymore.
$100 plus shipping

SOLD

As seen in pictures,
Used as preamp in passive system.
Balance control has no effect, never did. The light on power switch does not work. It was never hooked up.
This doesn’t affect functionality
$100 plus shipping
I can send more pictures if needed

I love everything related to quality sound 😉

Hey there,

I’m repairing this beautiful rotary mixer for a friend, I’m not very experienced / oriented with these kind of repairs, but still see it as a fun way to learn and wanna do my best to succeed on my own.

So, the problem is that the inputs (Phono 1, phono 2 and tape) are weak/unbalanced to varying extent. I did my best to show in these pictures below. Upon cue:ing through headphones, Phono 2 has a right channel that’s weak/dropping out. Phono 1 struggles with both channels: thin, rather bad sound lacking bottom, and also here the right channel is the worst of the two.

Tape 1+2 worked for a second, then went silent.

I tried listening both through headphones and through Program (master) out, and same issues.

My question would be if anyone has a schematic over this mixer, and if anyone would be able to point me in a direction of what components to be looking at checking? Preferably explained on a beginner’s level (like I am).

Thanks!

Hi all! Been lurking here for some time. I'm very interested in horn loudspeakers, and recently finished building a custom "BC" style horn (many thanks to Tom Danley for all he's done in furthering loudspeaker design and his generous contributions to the DIY community). Detailed post on the way. I mainly post over in the speakerplans forum but figured I'd chime in here as well.

Hi just joined as one of the many things I want to do in my imminent early retirement is build own systems for around the house and garden. Intending to combine with interest in ESP32s with aim to try and create own wireless system.

I would like to learn more about fixing amps as a hobby, I'm hoping I can learn a lot from you guys!!!

Hi,

I bought this a long way back but I will never get to it. Tubelab TL SE 2.1 board populated. Also a pair of Valve Art 300bs, A JJ GZ34S rectifier, pair of Amperex 5842 and an Edcor XPwr131-120 power transformer. No idea of the condition of any of it, it's as I received it.
Asking $250 for all of it plus shipping. CONUS only.

Hi everyone,

I'm looking for suggestions for BJTs with the highest possible voltage rating that would be suitable for use as the VAS stage in an amplifier. Ideally, I need transistors with high voltage tolerance since I might use them in a PA amplifier build as well.

I’ve been a fan of the KSC3503/KSA1381, but unfortunately, they’ve gone EOL and are becoming increasingly hard to source. I’ve also looked at alternatives like the 2N6517/2N6520, but I’m not too impressed with their performance.

Does anyone know of any transistors that match or even come close to the excellent characteristics of the KSC3503/KSA1381? Any suggestions or insights would be greatly appreciated!

Thanks in advance for your help!

LM3875TF full diy kitt for sale 29€ ,Payment by PP
LM3875TF genuine amplifier IC with bare Enig PCB.
Mono amplifier 56 watts rms good for Hifi stereo system or amplified speaker.
Tracked shipment to European union
Skematics sended together with articles.
If you enjoy this kind of stuff check my stuff related:
https://www.ebay.de/usr/rocksandsound

The boards were designed over many years, following the discussion on this thread

https://www.diyaudio.com/community/threads/technics-sl-1200-dc-power-supply.238618/

The PSU is a full rectifier bridge, followed by a quasimodo snubber, and then a CRC filter. It functions as any usual PSU board and two of them can be bridged easily for dual voltages

The regulator pcb provides an 8mm entry hole for a DC socket (or even a plain RCA one), which falls over the existing entry hole on the chassis.
It uses a 1A PPTC fuse to protect everything, followed by the last RC stage, and then the LM317 regulator. The output can be wired with a screw terminal for easy testing. And it also provides leds and test points for easy checking of the voltages around the regulator.








I currently have 11 sets of PCBs

Price is 25 euros for a set of two boards (one regulator and one PSU), including tracked and signed-for shipping to EU or the US.
Sorry to everyone else, I will not ship outside those two.

I will order more if there is enough interest.

Below you can see the schematics and BOMs for the two boards.
Give me a ping if you need more info

Regulator Schematics:





Regulator BOM and Notes: https://www.howtic.com/wp-content/uploads/2024/09/ibom-sl1200_entry-v.1.0.2024.p.html

PSU Schematics:




PSU BOM and Notes: https://www.howtic.com/wp-content/uploads/2024/08/ibom-PSU-small-v.1.1.2024.p.html

Hi, I have an HP 334a with some malfuncitions:

In voltmeter mode there is a little bit of jitter meter and into 300uV setting the meter read 100uV without input.

In distortion mode the automatic nulling doesn't work anymore and the read distortion is high (1.5% from PC soundcard).

Thanks in advance for the advices.

Guido.

To my understanding, bi-amping is an old technique that was used in the old days and maybe became popular in the 70s and 80s. The reason is that a Watt in those days was quite expensive. Nowadays, a Watt is cheaper. I'm curious whether anyone still uses the bi-amp configuration these days. And why are you still using it?

According to the user manual of my speakers, the ADS L1590, each speaker has a bi-amp switch located on the crossover network. It will bypass the low-pass filter of the woofers. In other words, the woofers will directly meet the speaker terminals when the bi-amp switch is engaged.

To date, are there any commercial speakers that have a similar function to the ADS speakers? What's the benefit of this function?

I'm considering building a desktop monitor system with two wideband drivers and a sub - where the sub would likely be a Dayton Epique with a couple of PRs.
I'm interested in having one driver, and crossing over to each voice coil from left and right.

The Dayton factory data for both drivers shows them as 8ohm - how would I model the TS parameters for just one voice coil?

I have 3 of these supplies I bought a few years ago and never used.

The Micro-Audio SMPS600 Rev. 4.1.1 is a high-quality, unregulated 600W switching power supply designed for audio applications. It offers a single-rail output of 55V.

Dimensions are 5" length, 4 1/2" in width, and 2" in height, with a weight of approximately 19 oz.

$40 ea. plus shipping

Hello dear diyAudio members!

I would like to ask for help with a Parasound A23 amplifier. The phenomenon is that one, the left side when in use, is very hot, while the right side heatsink, channels cold.
I assume that working point could be set.
I have no schematic diagram, maybe someone can help with this, even just a detail of where to start?
Or a service manual where I could possibly start based on measurements?
Thanks in advanced.
Br,
Csaba

I'm giving my 4 way OB full range dipole design for free under the "do whatever you want with this" licence.

I wrote a bit more about the whole project for the orion pluto lx forum (Linkwitz support group) and done a lot of measurements, this is a copypaste here.

Hi all. My name is Ben. I was born on may 21st, so 521 name (it's date when SL designed the baffle) made me very happy 😀. I've built and enjoyed the lx521 for some years now, and have preached everywhere about how great that speaker is. However, after a long time, I've decided to undertake designing and building a second set of similar yet quite different speakers. There were a couple of goals to achieve:
1st - WAF. Lx521 is very beautiful, especially so if you understand what it represents. But most people think it looks at least weird, if not ugly. I also moved to a smaller space with my wife and needed something more practical and "normal" looking.
2nd - keep all the bass performance, no sacrifices in function to gain WAF and practicality.
3rd - audiophile pals at my place and some at audiophile shows comment how voices sound strange on lx521. I thought about it a bit and, they really don't... but I think I got the gist of the issue. LX521 is a dipole behavior all throughout, meaning it kills room interactions as much as possible, both by radiating 8 pattern (not illuminating sides) and by keeping spectrally very similar reflections to the front wave. But in doing so you disconnect voices from the room and put them in the phantom image alongside the rest of the music. They won't sound like they are actually in the room to some extent - and this can be observed. I didn't really want to admit it because I really like SL and 521, but there we go, it's how it is. In order to get the great soundstage and reflections, you sacrifice a bit of intimacy in vocals. I tried to design a speaker that keeps the dipole behavior through the whole spectrum but expands the vocal range of around 1-4 khz by a bit, by making it radiate somehting between a dipole and omni in that range in hope of adding back that "like in the room" vocals. If that makes any sense. I already have a true lx521 reference anyway.

So after a long time, here is the result of my work. The speaker is called waffle. For the waf. My wife finds them pleasing. It's also possible to add black audio transparent cloth to mask them into black blocks.





next to the lx521









The speakers are made with 16 SB acoustics drivers, from my research really only them and SEAS, mybe scanspeak (expensive) and some vifas made sense. You need very well designed and build drivers with specific traits, like vented spider and so on. The drivers are very nice indeed.













Me next to the speaker, I'm 180cm tall.





The speaker has full vibration cancelling and 8 bass drivers total. I should point out that I'm not objective, obviously, but the sheer power this speaker commands is ridiculous. Insane amount of highly controlled bass is possible, down to what, 10ish hz or so. It's funny feeling that big articulated power coming from such tiny things, and the inherent complete vibration cancelling is great, absolutelly no vibrations anywhere, together with that monstrously powerful bass. It's weird. The rest is a typical dipole goodness, vast articulated soundstage, but there is a bit more energy in vocals and they do sound like in the room instead of being more ethereal like. It would be relatively simple to undo this with an attachment to the baffle and some more eq, and make it more like the lx521, but where's the point, just get the lx521 then. The 1-4 khz range still behaves like a dipole, just a bit less so, as you can see in the directivity and spectral plots below.
Every single one of 16 drivers in this speaker has it's own amp, so levels of damping and control are really good.
The amp is a 16ch class d amp with 250w per channel. The psu for the amp is literally just 3 atx psu's unearthed and in series to produce 36 volts dirt cheap.





Some measurements:

2.88ms gated on axis FR




1/12 oct smoothed FR




bass enclosure response nearfield (front and 2 openings on rear)




Lower midrange response nearfield (front and rear)




Distortion above 300 Hz, white line is thd (for bass you need something else, which I can measure/plot, but just didn't have the time and it will be good anyway as there really are no issues)




RTA maximum around my room




Spectral energy - this 60 hz spike is a room mode. I can see no stored energy above Schroder f, but it is raw so it looks ribbed. For pleasure. There is a bit of "fattening" between 1 and 4 khz, as predicted/wanted, but the on axis FR remains neutral.




Raw waterfall plot. Again, ignore stuff below 300 Hz.




Nearfield waterfall for low midrange.




Nearfield waterfall for subs. There is some stored energy but it's way below anything that would be an enclosure resonance (it should appear at 120 Hz, and it does, you can see it on the far right), and I can hear no problems. I was originaly a bit worried, but now quite sure it's actually room modes because the same pattern apears on the low mid too which has nothing to do with the lower enclosure.




Directivity. You can see some really nice dipole behaviour up to 1 khz and above 4 khz. 1-4 khz still exhibits dipole like response but it's much less pronounced, as it radiates some energy to the sides, making vocals more "in room" like but the on axis FR remains flat. As I said, it could be modded to be like a dipole all the way, but you can just have lx521 for that, and it would introduce some other problems too actually.





I'm no Linkwitz, obviously, but at least I have a hobby.

$10 plus shipping

Namaste from India. I want to build a inexpensive and good sounding set of speakers and I mainly need help with crossover design and some niggles in the cabinet design.
Looking forward to work with a passionate and knowledgeable community.

The letters aP in Class aP stand for analog Pulse; which characterize operation of this type of amplification. The goals, and proposed merit/value of Class aP will follow as I explain its operation, and undoubtedly from your input.

The generator of analog pulses is the Precision Rectifier [PR] shown in the schematic of the attached image. Here is how it works:
1. The operational amplifier [OA; actual is 1/2 LF353N] inverts sinusoidal input signal Vi.
2. OA has two independent and identical feedback branches emanating from its output and terminating at its inverting input.
3. Each feedback branch has a rectifying diode [actual 1N914].
4. By example of operation, allow the voltage of the shaded part of input signal Vi to increase. It follows that OA creates an inverted version at its output.
5. This step reverse-biases diode D+ of the upper feedback branch, and thus prevents input current [from the sine-wave generator] to flow through it.
6. The instantaneous voltage of the shaded input signal, and the value of input resistor R determine the value of input current moving from the sine-wave generator in the direction of the inverting input of OA.
7. This instantaneous input current [substantial in value] cannot flow in the inverting input of OA because this physical input has a high input resistance. It also cannot flow in the upper feedback branch because D+ was immediately shut off as mentioned in step 5.
8. However, this input current readily flows in the lower feedback branch because OA facilitates it by forward biasing diode D-; by using its important purpose to force zero Vdc or a virtual ground at the inverting input so as to match the actual value of zero Vdc ground of the non-inverting input.
9. Virtual ground is the electrical center point of the shaded parts of the input signal and the shaded output pulse. Both must be out of phase, and have equal;but opposite values for their voltage. This is an informal mechanism used to generate a negative pulse at output B.
10. A similar informal mechanism can be used to generate a positive pulse at output A.
11. This Precision Rectifier cuts the sinusoidal input signal [Vi] into two electrically independent mono polar pulses. Each pulse from this point forward will be processed separately. But both pulses must be processed simultaneously and identically in real time so as to recreate later on the original analog sinusoidal signal as faithfully as possible.
12. The analog pulses at the output A and B begin and end as close to zero Vdc as allowed by OA. This precise dual half wave rectification means that it is repeatable; but one needs to mind its accuracy which has to do with the faithful replication of each pulse regarding its parent portion [shaded and not] in the parent sinusoidal input signal Vi.

The next post will show a concept Class aP amplifier.

Best regards.

I'm working on a novel amplifier design in LTspice. I'm experimenting with cascoding the VAS transistor, but very often (seems to be kinda random) no current flows thru the VAS transistor and its cascode, or just a few pA. If the current gets started (for example by briefly placing a large voltage on the cascode base) then everything works fine. I have a vague feeling I've read about this somewhere before but can't remember. Is it a real-life issue or just an artifact of SPICE? What's the solution?

AS338 49.152 MHz ja 45.1584MHz oscillators carefully removed from Gustard U18. Used for two years.

Price 80 eur or $84 + postage for both.
I’d like to send these as a simple unregistered letter, all other forms of shipping will cost much more. Shipping from Finland, so EU preferred.

I had a BA3 preamp built to drive an F4 power amp, the case is a huge HIFI2000 one, there already is a dual PSU and enough space to either add the Pearl3 phono stage or a second BA3 and make it balanced.

During a trip to the US I bought extra BA3 cards to eventually either add one to the existing preamp and make it balanced or, in the future, make a simple and smaller footprint one, I also got the Pearl3 kit to build the phono stage, again, either in the same case as the existing BA3 or in a case of its own and then add second board to the existing one and turn it balanced which also means I will have to have the F4 modified to be run balanced.

Only balanced source I use is the DAC, would it make sense to go the balanced route?


Grazie

Giovanni

edit: it's a Pearl 3 phono stage, can't edit the title

I grabbed one of these from someone on Facebook because it would be perfect for hooking a turntable up to some speakers. I got it home and noticed the right channel didn't work with headphones or speakers and you would get occasional static sound in the right when turning the volume knob. I took the cover off and could tell someone's been in here, likely replaced the driver transistors as the heatsink is inverted from its original position and the solder doesn't look OE, I see flux in some of those joints. Before I give this back to the guy, do you think it's worth trying to track down the cause? I am cool if I have to invest some time and money within reason but the fact that there was prior work gives me pause. What do you think?

I read this post first...

Hi All,

I'm designing a compact Bluetooth speaker (with emphasis on low-end oomph and power) which consists of a Tang Band W3-1876S (4-ohm) woofer and a Dayton Audio RS75-4 (full range) per channel. This would be accompanied by passive radiators and I have the transfer function looking pretty good in winISD with PRs within excursion limits.



I wanted to crossover to the woofers fairly low 500-800Hz region to focus on bass and also due to enclosure size constraints they are down firing so I don't want them dealing with frequencies higher than this - hence why they are accompanied by full range drivers (which I will section off from the rest of the enclosure) so I can crossover lower.

I am using an existing amplifier PCB I designed with 50W per L/R channel (which I can limit down as DA + TB are 30WRMS combined).
Since both drivers are 4-ohms I was worried using them in parallel the combined resistance would be too low (TB doesn't offer an 8-ohm version of this woofer) so I started looking into series crossovers. I'm getting a bit muddled around phase alignment and also if I can introduce resistors to reduce the sensitivity of the full range to bring it in line with the woofer which I imagine negates my original reason for series crossovers.

I'd be grateful for any advice or if I should just design a parallel crossover and use the 8-ohm variant of the Dayton Audio driver and accept a combined resistance of 2.67ohms. I have limited understanding of the phase graph other than I imagine I'm looking for them to align as best as possible around the crossover point?

Also I appreciate this is a bit of a bonkers set up but it's just a bit of fun to try and make a speaker that creates a feeling of punching way above its size, I want it to confuse people when they hear it - open to suggestions 😆 Thanks!

Dear forum! I am glad that my registration has been accepted.
I started to refurbish a Rhode&Schwarz UPL Audio analyzer and I registered because I found a lot of useful information.
Mainly class A amplifiers that I build and RIAA circuits(JFETs and ICs). Nelson PASS f5 turbo V2 is my favorite.
I hope to learn a lot from the professionals here.
With thanks,
Csaba

Hello.
Need service manual for CD player CAMBRIDGE AUDIO 350C.
Hi is stuck in standby mode.
If you press the ON button it turns on for a second and comes back again to standby mode

Thanks

REW (V5.40 beta) by @JohnPM can make loudspeaker measurements using the Fast Subband Adaptive Filtering process, developed by Michael Tsiroulnikov @mikets42
This FSAF implementation can use noise (white, pink, brown) or a segment of a user-supplied file e.g. MUSIC (!), to measure the frequency response, as well as total distortion (harmonic + intermodulation) + noise.

Reference:
https://www.roomeqwizard.com/betahelp/help_en-GB/html/fsafmeasurement.html

Shall we test this out? Here is a picture of the setup:

Here is the amplitude response of this driver in box (ie. without filters or crossover)







Frequency responses were measured by

A- logarithmic Sweep (aka chirp (devised ~2000 - link: AES)
see attached .ZIP file for "1 M Measure sweep 0Hz to 22050Hz"

B - white noise via FSAF, devised 2020- link: MATLAB Central File Exchange
see attached .ZIP file- " White noise -12dBFS"

C - "Put Your Hands" music clip via FSAF. This music clip is courtesy of Dr Stéphane Pigeon, a signal processing engineer. You can listen to the clip here - scroll down to near the bottom of the page to section and click on Play/Pause button:




EDIT 19/10/2024
Distortion residuals added

• Virtual audio cable (digital internal loopback)
• Focusrite Scarlett 2i2(3rd gen) (line out to line in)
• *Scarlett 2i2(3rd gen) line out -> Hypex UcD400MP -> Scarlett 2i2(3rd gen) line in

TBC - the graphs, and sounds of distortion from this speaker, and other speakers...

Is it down to room placement or treble loss? Just seems that in our current ipod dock/ playing music off laptop era, people are more likely to be moving around a room ie bedrooms or workplace; there are many advantages to the omni.

At the end of last year I was talking to Jim @6L6 about some project ideas, and the OPA1656 / BUF634A Headphone amp came up. I decided to make some prototype boards. I built up a board last night and the sound is nice!

Concepts considered for this prototype board included:

• Make it 100mm wide to slide into a Hammond chassis. PCB is 100mm x 50mm
• Keep it simple
  • Start with the datasheet schematic - the good engineers at TI know what they're doing.
  • I wanted to dabble with Crossfeed, too. I made some separate boards for trying those.
• Install some sockets to allow flexibility to play with swapping gain resistors and bandwidth resistors.

The schematic is attached.

Potential future concepts:

• build it with a regulated power supply on board including a transformer.
• include a crossfeed circuit with a bypass/enable switch
• make a tiny version to add to a preamp

I have kitted up a few of these with SMD's pre-installed. 2 are spoken for, and 2 kits are available.

Giveaway:
1 OPA1656 / BUF634A Headphone Amplifier PROTOTYPE Kit.

Rules and conditions:
One entry per person (obvious, but worth saying).
If you're in the USA I'll pay shipping. If you're outside the USA, you will need to pay shipping. As long as USPS will ship to your country/address, you meet the criteria.
If you'll use the kit, sign up. You must be willing to build it up and comment on the sound within a month of receiving it

How it'll work:
To enter, just copy the list of entrants, paste into a new comment, add your DIYA username to the bottom of that list and post. In 48 hours or so, I'll make a comment saying that entries are closed. I'll take the final list of entrants, paste them into an online randomizer, and the name that appears in the top 2 positions will be the winners.
From there, that person simply needs to PM me their mailing address and I'll get them posted.

All parts are included to build it up EXCEPT for the 3-position disconnect block. I have included 2 "pigtails" for 9V batteries, so you could easily start with 2 9V batteries.

Full reel of THAT4301, NOS DIP version

In total 18 pieces, never been used.
Came directly delivered from THAT, so 100% legit.
(These were used in PRO-audio equipment, which reached EOL)

15 EUR per piece ex shipping
Or 220 EUR for the full reel ex shipping.

Prefer to ship the whole reel at once, but maybe there are a couple of people interested.

Ships from EU

Hi, looking for some KSC3503 amd KSA1381, I am in the UK for shipping, anyone have any?

Thanks

I made a couple of cheap Bench PS myself from components from Aliexpress. Total price is around 60-70eur for both. I often need a single or dual PS for testing various DIY devices. The concept is an AC/DC fixed power supply 48V 4A, then a noise filter 50V 4A, then an adjustable DC/DC step down power supply (with a current limit) of 50V 5A and again a noise filter 50V 4A. The devices are not grounded to IEC, so I could make dual power supplies up to +-45V. Realistic possibilities are approximately 45V and 3A. Plastic box - 160x160x65mm.
Links:
https://www.aliexpress.com/item/4000287613667.html
https://www.aliexpress.com/item/1005005396072901.html
https://www.aliexpress.com/item/1005007948946980.html
https://www.aliexpress.com/item/4001224998003.html
https://www.aliexpress.com/item/1005003597145707.html

I am coming to the end of a long build that ended up being 90% in the presentation, mainly because I hamstrung myself by aiming for a small footprint.

Anyway, now I am looking for something where the tube electronics take the forefront, so I have dusted a pair of UNSET Power Head (UPH) boards I bought last year.

Below is a mapping of the parts numbers on the UPH board to the original Unset BOM in the first post of that thread.

Next I looked at sourcing the PFET, FQPF9P25 or FQAF9P25, which has become obsolete, as mentioned by George in 2023.

Is this one a suitable replacement? IRFI9634G
CRSS is 40pF instead of 27pF, and that is cited as being a key parameter on the UNSET thread, but looking at other posts on other threads, the suggestions there are normally worse than this. The gate-source threshold voltage is 4V instead of 5V, and the max current rating is 4.1A instead of 6A, but otherwise looks to be similar to FQPF9P25.

Hi I need a bit of advice I've tested my speakers that have been in storage for 15yrs at very low volume & sounded OK before ordering my 4 channel Hifiberry Beocreate 4 amp with dsp & UMIK-1 for measuring all new to me need some advice on capacitors to protect the tweeters so I can play around with the software I pick things up quicker practically once I get the hang of things even hopefully upgrade drivers in cabinets I've uploaded Data Sheets of drivers after checking the part numbers I've had them from New thanks for any help

I have a 6j1 vacuum tube preamplifier. I recently switched USB-PD chargers and usb-pd decoy instead of a 12v adapter. I love the fun of these modifications.

Hi team - I am a seasoned engineer and musician, who recently decided to pivot towards building, instead of just buying. I am in the process of building my own stereo system (emphasis on "stereo", no home theatre, no surround, no Atmos, just old fashioned two-channel music), with a mix of professional, home-built and consumer equipment. I'll be glad to partecipate, learn and contribute.

Hi,
I would like to ask you a question, also at the risk of it being a stupid question
After almost 30 years of doing nothing, now I've finished my two ACAs. And they are great. But - the diy-fever is here and I want more. One thing is certain: the next project must be another Pass power amp... but which one 😕 So here it comes, the stupid question: is there a "ranking" of the power amps? Is an F6 better than an F5 better than an Aleph J better than an M2x... and so on? They are all great, but are they only different at the same high level of the sound quality (what comes first for me)?
Thank you for your help in making a decision 🙂

Cheers

Without put them in circuit and measure result, of course!

I was wondering about how to check authenticity of the chip. I got a numbers of chip when it was scarce from various dealers. Just want to check them before putting them in my next project. Apart from buying from reputable dealers and obvious dodgy looking chips, I have seen very convincing laser-engraving counterfeit chips/parts that often work but might not up to spec of authentic chip.

As a result, I thought that maybe we can measure resistance or using diode function or other measurement from basic DMM or oscilloscope to measure them? For instance, TI publishes equivalent schematic and shown BJC power transistors between output (pin 3) and V+ (pin 1, 5) and V- (pin 4), so I should expect measuring between base, emitter and .45 ohm resistors between pin 3, 1 and 3, 4? Additionally, input transistors could be measure at pin 9, 10 and V+ (base and collector)? They should have similar result?

Additionally, measuring resistance between power supply pins and ground (pin 7) should yield reasonable results, but what are ranges of reasonable result should I expecting?

Thanks for your comment.
AP

Hi! When I use dc heater supplies (say in phono stages) I usually elevate the heaters above cathode potential. As I understand it there can't be a flow of electrons from the heaters at a potential positive to the cathode and no potential hum couples from the heaters into the signal. But what happens now is that the signal on the cathode couples into the heaters, right? Or does the cathode resistor bypass C provide a lower impedance path to ground and this wouldn't happen?
And if it happened could it be an issue of some kind? Say e.g. in a stereo amplifier with parallel wired heaters would it have a negative influence on channel separation?
Thank you for your thoughts and maybe even experiences.

Have a lot of old catalogs, manuals, tube reference material, etc. Been collecting for over 35 plus years and this is what is left. There is a few items on Mac stuff, tube amps and preamps, etc. Also Hi Fi Spotters guide 1&2...Wish to sell the entire lot. Would like to get $20.00 for the lot. Comes out to about 10 pounds of stuff. Shipping should be about $15 bucks... Hope someone still collects this stuff. I accept PP as F&F or postal MO... U.S sales only.

Of all things, I am looking for the little cap that covers the top bearing screws on a Technics EPA-100 tonearm. Let me know if you have a big NOS stash of those hanging around and you'd be willing to part with one.

I’m trying to get the design of a JBL go 3 voice coil, the width and length of the wire. I want to try to make one

Long time Tube guy who stepped it up a notch when I got involved
with Don Garber's gear. (421a, EVO pre and Super X).
Not a DIYer, but have recently come into possession of an EleKit 8550,
built by (Paul?) at Tubes4HiFi, (mine is pictured on P. 4 of VKmusic's
8550 thread) that led to the purchase of a SUNVALLEY s1645D from
Victor, nothing but good things to say about Victor's service!

Hi everyone, been poking around diyAudio for a while, reading lots of stuff regarding LM3886 mostly, I'm in love with these things!
Always had a great interest in wiring stuff and music, so I have had a great time reading all these posts.
I've also built my tower speakers and put a few boomboxes and amps together...

Hey let's be honest, we all make mistakes. Some are pretty dumb. And when you get into the audio world, dumb mistakes can be costly.
Just yesterday I was playing my Kenwood KA-7100 and moved my speakers while it was playing and shorted something out. So dumb 🙄. (Taking donations on that repair. 😉)
So anyway, maybe you all could share some mistake you've made, especially in the audio world. The more costly the repair, the more interesting it will be. Thought it might be interesting for us all.

Hello guys,
I just wanted to share roughly made SPICE model of 2SK880-GR n-channel JFET I just made.
Enjoy!
O.

.MODEL 2SK880-GR NJF(
+Beta=30m
+Betatce=-.5
+Rd=19
+Rs=19
+Lambda=32m
+Vto=-500m
+Vtotc=-2.5m
+Is=10f
+Isr=1p
+N=1
+Nr=2
+Xti=3
+Alpha=10u
+Vk=10
+Cgd=7.3p
+M=.3622
+Pb=3.2
+Fc=50m
+Cgs=11.5p
+Kf=.001f
+Af=500m
+mfg=Toshiba)

I'm having trouble with crossing this ribbon (GRS RT1.R) with this planar mid (GRS PT6825-8). I can cross them anywhere from 2k-8k and there ends up being a dip in response immediately once you go off axis even a few degrees. How can this be? I've modified my XO to be nearly all 4th order filters to try to keep them in phase. If I go any less, even a 3rd order, they will be in phase at the XO and then a few thousand hz later they will be out of phase and cancelling out. The same thing seems to happen to the mid and woofer crossover. The woofer is just a cone woofer. It is far less pronounced with the mid to woofer than with the mid to ribbon XO. I am not understanding how this can be.

Is this just the nature of ribbons and planar?

I managed to get the woofer and planar XO halfway decent.

This is designed to be listened to at a desk so it isn't that horrible of an issue but I would like to understand it.

The drivers are not vertically aligned. Here is what the unit looks like. I have entered the offset data into the XO. Even if I removed the X axis offset from the data. Essentially making them vertically aligned, it makes little difference.


Here is the current XO. You can see how big of dip there is at even just the 15 degree mark

Then here are the responses of the tweeter, mid, and woofer respectively. Notice how crazy these responses on. I had to hammer these things into shape to get anything like an accurate response.

Woofer


Mid

Tweeter

I took these measurements with a jig so that the microphone was positioned exactly at the front of each driver when taking the measurement. It was aligned with the face of the unit so that the Z offset would be taken with the data.


I'm sure there is just something I do not understand here. If anyone knows, please let me know. Possibly its just hard using these types of drivers. That I can accept as I didn't think this would be easy. Odd parts cause odd issues.

Lastly, someone mentioned to me to hit ctrl+alt+E to fix phase issues in REW. Does anyone know exactly what this does? It seems to affect the delay. Wouldn't this throw off my Z offset data that would be inherent to the measurement?


As always, thanks for reading. Any and all responses will be read and appreciated.

Mine are labeled "050/1 1201 Norway". You can see them in a photo of a disassembled XDS at Audioholics:

https://www.audioholics.com/soundba...nht-xd-loudspeaker-system-review/Graphic5.jpg
https://www.audioholics.com/soundba...nht-xd-loudspeaker-system-review/Graphic6.jpg

Full review:

https://www.audioholics.com/soundbar-and-satellite-speaker-reviews/nht-xd-loudspeaker-system-review

I don't need exactly what the XDA processor expects as I'm doing the digital crossovers in software.

I have old seas P14RCY can it make a 2-way speakers? Or anything benefit.

Thank you

Ps i ever use it with P25Rex and it is shout. Then I remove

I'm busy working on a layout (just one tube) for a 6N3P-E based hybrid preamp with feedback (horrors!), run by a little Antek toroid with a 150V HV regulator of my own design using a 500V p-channel mosfet I nabbed from Electronic Goldmine. I'll be using the ZVP2120GTA p-channel mosfet (SOT-223 SM package) from Diodes, Inc., as it has lower gate capacitance than the IRF9610 mosfets originally used in the design (zippier performance). Details will follow as I get the design worked out.

I originally posted this as an aside in the Salas 6V6 preamp thread, but the project has since acquired a life of its own, hence the separate thread.

Can anyone figure out what's going on in the Danley CS-30? I can't figure out how they're getting a bandpass-ish response curve along with an impedance curve that almost looks like a sealed box.

Based on some comments from Ivan Beaver, it looks like the CS-30 complements the TH-Mini well, so I thought I'd pit them head-to-head.

(According to Beaver, the CS-30 digs deeper at the cost of low frequency efficiency, but the Mini has higher efficiency *and* higher power handling than the TH-Mini in the octave from 40 to 80hz.)

Comments here:

zmarchive.com psw-srf: 35103 Mini Subs

Hey, have Yamaha MX-600 stuck in protection mode. All outputs are out of circuit and still in protect mode.. What to check next or just rebuild protection circuit. Relay has been replaced and + and - voltages coming off of bridge to main caps..
Input greatly appreciated

Hi all,

I built a fun speaker a while back based on the Mark Audio CHP90 in a bass reflex design using some big oak slab baffles. Very rustic chic. I've been using active DSP on them to handle any issues from the overall baffle changing the response. I recently took them outside to do some measurements to get a better pseudo-anechoic response so that I could export it as an in-baffle FRD and used my DATS to generate a ZMA from in-baffle as well. The goal being to take these measurements of the driver in the cabinet and work on them in VituixCAD to alter the frequency response a bit in a passive crossover, even though its not really crossing over.

I'm attaching my VituixCAD file for anyone that wants to play with it to help out (renamed to *.txt, just remove the .txt and it will be good to go)

Overall I'm just trying to flatten it a bit. Doesn't have to be a heavy natural house curve, but just flattening it would be a nice thing for me. I don't particularly want to make $100 crossovers for this, but I'm just seeing what I can do and what I can tolerate with some basic passive components. Any advice or criticism is appreciated!









I did farfield impulse response gated measurement of the driver, and then did near field of the driver and port and scaled the port's output via area and then summed the near field response. Then I corrected it for the baffle to full space. Final measurement:

As you can see there are a few big spikes I'm trying to potentially tame down, and then maybe lower the upper end in general to flatten it out. Those spikes are around 4200hz, 6400hz and 11800hz.

I used this measurement to generate an in-baffle FRD.



I used this DATS measurement in-baffle for producing the ZMA.




I'm currently working in VituixCAD. A few options, the response on its own and some of my efforts so far.

RAW response in VituixCAD with no components:




Here's one approach I'm looking at:






And then I went overboard with notch filters to hit those 3 spikes. Overall this seems silly and wasteful. Maybe there's a better way? Looking for advice on that.





Any suggestions appreciated!

Very best,

Any suggestions where I can get a replacement for a Peerless K040MRF medium frequency driver or what drivers I could use in place of a damaged unit. It looks like this.
-
I can't find one on Ebay in the UK. It is in a Pro9TL Mk2 cabinet and has failed completely. This thing has a sort of a can on the back of it so doesn't depend on an enclosure which makes replacement difficult.

Hi DIYers,

After a few difficult years with the further realization of how short life is, and that it can be forever changed in a day, I've been led to a place where I feel if I'm going to achieve life's little goals, now is the time. One goal is a dream speaker, a 3-way of the highest resolution and sound quality, along with good aesthetics, to rival $100,000 high-end speakers. This is not a "no-compromise" speaker, as every decision is a compromise in some manner. Speakers will be used for everything from orchestral, classical, acoustic, pop, movies, and video games in a residential system.

I implore people to recommend 15" woofers, and interesting 12” woofers are also considered, as there is no possibility of hearing these locally. I have mostly been looking at big radiating area, because I like the way they present recorded elements as room-filling and life sized. I also consider myself among a smaller number of listeners that prefer an over-damped, fully stuffed cabinet. My current speakers are Yamaha NS-1000M and Quad ESL-989 electrostatics, and I would like the future speaker to share the high-resolution traits these provide, but with more extension and sensitivity similar to the NS-1000M.

Some drivers I have modeled include a small number from from TAD, Acoustic Elegance, B&C, BMS, LaVoce, Eighteen Sound, Audio Technology.


The bass parameters can be changed as the physics require, but mostly center around the following:

• Low-pass crossover point of 450Hz, depending on mid might be 250Hz.
• 8-Ohms nominal impedance.
• About 94dB sensitivity at 1W. System goal is +88dB after baffle step compensation.
• Aperiodic or Sealed enclosure, 100 liters target. 150L max, as it the bracing and curved wall thickness makes the speaker large.
• Enough extension to not need a subwoofer. This one is sometimes at odds with sensitivity and enclosure volume.
• Rolled or accordion suspension are welcome for longevity. Ribbed paper cones are great.
• 100W power input handling.
• Will be used with solid-state amplification.

Hello.
I register here, because i have a problem with an Audio Card.

Is there a Linux distro in which the APS (Audio Production Studio audio card, by EMU) is working "out of the box" ?
I have test it in AVLinux MX 19.4 (for 32 bit) and it is not working.
Or if there is not, then does somebody know a patch or a setting or something.., that will make it give sound ?
I have tested, in the same distro, two other cards with the same processor (EMU10K1) and they work "out of the box".
Thanks