Hi All
I am very new to AKABAK 3, although I have used AKABAK 2.1 for a while. My question is, after I have calculated and displayed the sound fields generated from the AKABAK 3 model, closed the model and saved it. How do I get AKABAK 3 to redisplay the sound field data without recalculating (takes hours)? I see there is an *.AKBPE file that I have tried to reload, but no responses show up.
I have the Student Version.

Thanks for your help.
-bw-

Recently, doing evaluation on componenets and systems, I started listening to somewhat more "advanced" and audiophile recordings😉

I'd like to share here what seems to be sounding good, is well recorded and presents quality, interesting audiophile material. I'm always on a lookout for that type of recordings, so I hope this thread will continue and will be updated on regular basis, providing a source of inspiration on what to look for next time you visit your local records store.

So here's the first run. Most of you are probably familiar with Jacinta's album. Patricia Barber's, Companion, is also very good live recording. Burmester CD III sampler is my all time favourite and it contains all kind of different material, from classical, jazz to more contemporary stlyles and even Chinese percussion track. My recent buy, Holly Cole's Temptation is great adaptation of Tom Waits songs.

I just bought a pair of JM Lab Focal Megane Carat. They sounded amazing when I bought them, but of course immediately one woofer started rattling. I very gently pushed the cone to check for voicecoil rubbing and the dust cap just peeled away. That stopped the rattling but now there's no dust cap. I guess the dust cap was just flapping against the cone causing the rattle. Hopefully that's all it was.

Anyway. I don't know what adhesive I should use to re-attach it, or if I should just replace the woofer.

It's been a while since I've done any DIY or made any audio purchases, so I'm "under moderation" and I can't contact or reply to this older listing: https://www.diyaudio.com/community/...ge-pair-dual-voice-coil-7-inch-nh-usa.390049/

Any advice is welcome; Happy New Year.

I've been thinkng of setting up a rig to do some basic headphone measurements. It occured to me that I have a TEF-10 analyzer sitting in the basement, that I bought new in 1983 and mothballed in 1989 (after upgrading to it's big brother TEF12+). After locating the box of 5.25" floppies it uses , I decided to boot it up and give it a spin. To my great surprise, everything works fine! All of the 33- to 38-yo floppies are also good. This defies everything I've read about floppy data retention.

Thought I'd post some eye candy for those that are unfamiliar with this amazing machine in its day.

The plots are measurements made in 1988. One of them is the anechoic mag and phase response of a polycone tweeter on a test baffle. At 3dB/div, not bad for a cheap driver. The time offset isn't quite dialed in for accurate phase representation - a couple uS off still - but it was close enuf to see that it was minimum phase. The other plot is a 3D "waterfall" display of an unidentified speaker system.

The only thing that makes me think twice about using this system today is the floppy drives.

The first time I did I was pretty surprised at how low the numbers turned out to be.

I typically listen at around 70 dB, and rarely - if ever - see peaks much higher than 90 dB. I don't have a setup to let me measure the acoustic levels, so I just use a scope and assume the phone specs are close enough to get me in the right ballpark. No claim of precision here.

With my 32 Ohm, 100 dB/mW phones the raw measurements show only a handful of mV RMS with peaks below 100 mV (and usually below 50 mV).

Do you ever measure your listening level? If so, what do you find?

Just curious

jason

My Marantz SR5008 receiver was shutting down due to a thermal protection error. It took me a long time to properly diagnose this failure, because it was sometimes shutting down after only a few seconds, sometimes after a couple of minutes, and sometimes it was functioning properly for a few days.

You can manually bypass the protection circuitry by pressing power+display+status+sound mode. 'Protection pass' is displayed, and everything was working fine. However, this is not a solution, so I tried to figure what the problem was by disassembling the amplifier-radiator module (7ch amplifier).

I measured the PTC resistors, and there was some variation, but I was not sure if replacing them would solve the errors. After reading another post on this forum about a similar amplifier (denon x1200w), I decided to disable the thermal protection for ever.

See attachment where to break the lines on the PCB of the amplifier module. Caution: you have to break/stop lines on both sides, so you have to desolder the power transistors. Of course, your amplifier is not protected against overheating, so only perform this operation if all other options failed!

After this has been done, no thermal protection errors, and my amplifier has been fixed!! 🙂

If you have any questions please send me a PM.

What if the horn woud be constant directivity extending way beyound the speaker basked and its back side was sealed towards the basked?
In having 4 elliptical holes in the horn could we approximately achieve what the K402 MEH does?

Is there anything there for us to use? If yes, what kinds of things have you been able to get it to do?

Or is the answer 'it doesn't really do that yet'?

Working on my multicell horn and reading of some other K threads lead me back to the idea of trying out a K-Tube on my JBL2445. There are 4 models attached - single and dual slot, each in two lengths. The shorter one is around 1/4 of 500 Hz wavelength and the larger one is maximum size for my QQ-S printer. I will start printing today so that they are ready for the big polar measurement race between multicell, 2380 clone and K-Tubes (scheduled for mid October due to work travel🙁 ).

I have recovered 2 chokes from an old UPS system, with my LCR meter, they measure:

• choke 1: 2.8 mH, 0.19 Ω DCR, Q=4.87, wire Ø 1.6 mm
• choke 2: 130 mH, 0.88 Ω DCR, Q=3.37, wire Ø 0.9 mm

I'm into tube amps, where I usually see higher L values in DC filtering. Is there any usage you can see for them, or should I avoid adding them to my cellar stack of heavy metal ?

Hi, I want to build my first DAC , I don't care about performance, just for fun.
I was looking at AK4117 for spdif receiver, and I don't know how to config it, can I by PINS ( switches to select different modes ) or I need a micro controller, processor for that? .
Can it run by itself?. no MCU,
For DAC , CS4360, CS4340, PCM1680,
- Old ic's here. I know. Just wanted to build something for fun if possible.
- Cheers, Bruno.

Need space for new project therefore would like to sell this rarely used speakers with powersupply of course.
Asking 700 Euro + shipping from Germany

thx

I'm here just to pick a mid its currently between 3 drivers.
first of all this build is using 2x 12in woofers in the bass (Vifa M30wo-15) and a vifa D27 tweeter.

for cost i was just going to get a Peerless SDS-P830657 6½" but i saw some Dayton 8in's that look better on paper then the peerless they are the DS215-8 (paper cone) and DSA215-8 (Aluminium cone)

theses look to have a better off axis responses than the peerless (and i think they look much better and much easier to counter sink)
i would get the paper cone but there out of stock for quite a while so the peerless or dayton 8in

Xover will be about 500hz for the bass and mid to tweeter would be about 2.5 to 3khz

SIDE NOTE
The Vifa M30wo-15 don't have a specs sheet and i cant find on the on web but i did find a close one below VV
(http://www.sea.vg/vifa/M30WO-49-08.pdf)

that spec sheet states that they have a 93dB sensitivity at 1 watt (mine are 4 ohm and the spec sheet is for an 8ohm coil i know) but i am getting a dayton DAT and miniDSP UMIK-1
and i would like to get the mids at the same time as the only place that sells it is over seas and would prefer less shipping hassle.

i also already have these the Vifa M30wo-15 drivers all 4 of them. 1 was damaged and had to dissemble the driver to fix the bad glued coil
they also date to 2001


Any help would be largely appreciated XD.

My English made Audiolab8000M mono amplifiers are at least 25 years old and I am thinking about replacing the 10,000uF smoothing capacitors. I just want to find out what the physical dimensions of the factory fitted capacitors are without trying to measure them in situ. I have a few possible contenders for the replacements and Mundorf mlytic ones seem to be suitable provided they are suitable size wise. If you have done a replacement recently could you help me by measuring the old capacitors ?

I'm looking for an RC-based RIAA preemphasis circuit to apply RIAA equalization before vinyl cutting. This circuit is crucial for validating the theoretical accuracy of my phono amp design in simulations. Ideally, the output post-phono preamp should exhibit a flat response. While practical RC values aren't essential for simulation purposes, the circuit should accurately generate a Preemphasis RIAA curve.

At a recent close-down sale (Wilko's for the UK-based members) I picked up four Acacia wood salad bowls for a very low price with the intention of using them for a pair of speakers, using a pair of Jordan drive units I've had for a while.. The bowls aren't really hemispherical and two joined together make more of a barrel shape. The speakers will be reflex ported and calculations suggest they should get down to close to 60Hz, which is fine for the office type use-case I have in mind. Anyway, I've now started work on them.

Click to expand...

Hi All,
My first post so please be kind.

Have wanted a pair of Mission 770 for a long time I picked up a pair of 770S's for the sum on £33. I was aware that the woodwork will need some TLC but I'm a liitle concerned regarding wiring and speakers fitted. It does seem that the orginal drivers were replaced long ago. Each speaker is fitted with Vifa M21WJ-09-08 and I beleive that the tweeters are SEAS(?) 25in H377. I cant certain but I have a feeling that the crossover circuitry (can anyone help here as i dont have a circuit diagram for this) has been rewired(?).

I've attached some pictures. Are these rubbish or repairable?? I intend to drive these with an old A&R A60 Cambridge (an early one) which I am going to recap very soon.

Thanks

Rob

https://www.flickr.com/photos/65588479@N08/shares/U916Y3

It's kind of a W.C. Fields movie -- I know where every cable is. The most frequently used are immediately at hand, like the 12 inch bananas which go from power supply to DVM's, or the banana to mini-grabber, bnc to mini-grabber etc:

I wonder what is your opinion about a Levinson 23.5 for lowend duties o a Infinity QLS Watkins woofer? In the past I had a Levinson ML-3 which I used on Acoustat full range speakers. I liked it and it was easy to service. Now I can't accomodate that size anymore hence my question about its successor.

I have just bought a Fosi BT20A Pro T-amp that is much hyped at the moment. It is based on the TI TPA3255 chip, the big brother to the TI TPA3116 chip
that I have in 3 other amps. Those 3 are Breeze Audio amps, and I actually like them a lot. They are quite cheap but perform very well.

All four amps are upgraded with LM4562 op-amps in the input stage, which are my preferred chip op-amps. I like Sparkos SS3602 discrete op-amps better,
but that is not the subject here.

And the subject is also not if 5532 is the world’s best op-amp. It was 50 years ago, but it is not now. It does not sound good, and it does not measure good,
so let us totally forget about that.

The Fosi BT20A Pro is well rounded, a little mellow almost like an old tube amp, and it does not have the slight boost in the higher midrange that the TPA3116
amps have, but compared to them it does sound a little less immediate. It has 2 replaceable 5532 op-amps, and 2 SMD mounted 5532 op-amps. I am afraid
the SMD chips is a design flaw.

The Fosi has a bass and a treble control and a separate pre out, that the others don´t have. I am not sure what the SMD chips are used for, but I am afraid that
they are for the tone controls, and therefore ruin some of the immediate sound of the amp, because you cannot dial out a tone control, even if the controls are
in the middle. They are still in series with the signal.

Does anyone know what the 2 SMD op-amps are used for, and did anyone make a mod, to get rid of them?

I am sure that there is more quality hidden in this amp, and I don´t care if I lose the tone controls.



Thanks in advance
Arthur.

Hey, I'm just wondering what I should do with the oscilloscope ground clip when measuring audio from my PC, DSP and amplifier. Is it safe to just connect it to 3.5mm/RCA ground on all devices without shorting anything? I guess a local ground would give me less noise for measurements.

Also, I've seen a lot of posts telling you to not "float the scope (remove earth)" but in this case I can't really see any dangers if I'm just connecting it to aux "-" outside my PC, it's not like I'm opening up a PSU here. Is that a good idea?

I have a SDS-1104x-e, so not battery or USB powered.

I have a pair of Snell Type EIIs that I'm restoring. Have all the correct replacement bits supplied by Steve Flynn at Atomic TV and Hifi. They're the official Snell repository of parts, service, and technical information. They are the place for Snell stuff!

I'm not making any modifications to the speakers, just restoring them to original specification. Except, perhaps, that I'm considering adding some kind of cabinet stuffing, filling the inside and/or walls of the cabinet. Snell didn't originally do any of that. There's no polyfill in boxes originally. It's a ported design. My sense is that it's mostly desirable to have the inside of the box as quiet/damped as possible, though with a ported design you have to be careful about affecting air movement through the port.

Of course, if I do nothing I'll get a speaker that should perform the same as it did when it left the factory, which could be okay.

Are there any benefits or issues of adding some polyfill or resonance reducing wall material to the cabinet?

Thanks.

Hello all,

Another project I will never get to - a pair of new ICEPower 500A modules (rev G) with a SMPS power supply. Also has the input and power cables for the amp modules.

Hows $220 shipped Conus?

I recently had a problem with our large cat (6 kilos+) knocking over one of my PMC GB1i speakers. So, motivated by that rather than sonic improvement, I made granite/cork sandwich "feet" for them.

The project was fairly inexpensive: £22 for two packs of granite table mats, £10 for 1mm cork sheet, and another £10 for diamond drills. I've gone into a bit more detail here: https://thetucks.com/post/pmc-gb1i-granite/

I bought a IT21 tube tester on craigslist and am having problems and hope someone can help.

The unit powers up and the set line switch works, the meter gets to the middle of the dial and everything seems fine to that point.

When I insert a tube, set the switches and then use the test switch the meter always pegs all the way (good or bad) never a reading in the dial mid range.

I opened the unit and found an additional resistor wired in parallel to the 75k ohm resistor. The additional resistor was around 500k ohms. It isn't in any documentation I can find.
I removed the extra resistor but the meter still pegs when testing a tube. I checked all resistors in the unit and they all test OK but
when I teak a reading across the 75k resistor I get a reading of around 1000 ohms. I take a lead out of the circuit and the resistor is 75k ohms.

If someone has an IT21 and can do a check of the 75k ohm resistor and let me know what it reads in circuit on their unit I would really appreciate it.

I looked and do not see any parallel circuit in the tester that would bring the value down and I don't see any mis-wiring in that area of the tester.

Thanks for any replies.

Jim

HI Everyone,the front stage board of my Krell s300i amplifier is producing noise and urgently needs to be repaired. Can you please provide me with a blueprint for the front stage. Thank you

Guys, I bought a KRELL KRC from ebay, and now the device is plugged in, but it doesn't give me a "power on" message, only the power light is on, and any button presses have no effect. I have a certain ability to repair, but I lack a maintenance manual and don't know the working of the MCU clearly. Hopefully we can wait until the guys get a repair manual or hear from someone with experience. Thanks

SOLD Sylvania 10y tubes mint .Tested on a Hickok TV7 AU .
76 and 73 were 38 is low
plus shipping
thanks Rick

I bought 2SA222SG and 2SC6144 transistors (fT=230Mz, hFE300) for PSU pre-regulation along with *V zener blah...
After watching JohnAudioTech video building an unbiased class-B amp I thought the above might be candidates driven by an NJM4580 op-amp. I plan to build an amp to drive 10 watt - 6 ohms speakers.

What concerns me are the huge gain of 4580's 50mA x transistor's hFE 300mA and the Ic capacity of 10A!
If I have provided enough information could someone inform if I'm on track to destroy the transistors, or safe to give it a try. For sure negative feedback could prove a challenge - I'll live with that.

Best wishes to all and a Happy New Year!

I own a pair of Focal Profile 918 speakers.

I had a problem of oxidation in both the tweeters, so they are not working properly anymnore, even after a repair attempt to make them work.



That said, I'm planning making an upgrade on my speakers, including some mods on the crossover. A friend of mine is going to do this work, since I don't have the required knowledge and skills to do so.

Because of the problems on the tweeters I plan to replace them. And given that Focal tweeters are quite expensive, added to the fear of the oxidation problem happening again, I would really prefer to buy new tweeters from another manufacturer.

So that's the reason of this post: which aftermarket tweeters would you suggest to replace the ones in my Focal Profile 918 speakers?

Thanks.

P.S. - By the way, I'm aware that the tweeter compartment on my Focal Profile speaker is quite reduced to accomodate a bigger one, so I have the idea of making some extension on the top of the cabinet to accomodate the new tweeter. Maybe something like this 👇

One pair of Yuichi Arai A320FL (also known as A290FL) hypex wood horns.
2" (50mm) throat entry, hypex profile.
Loads the driver well down to Fc = 320Hz.
Manufactured in baltic birch plywood, by ALG in France: http://www.alg-audiodesign.com/portfolio-items/arai-a-290-fl/

Excellent condition overall.
Asking price 500 GBP for the pair. Payment by PayPal, or cash on collection.

Located in London (UK).
Worldwide shipping possible by Parcelforce (ask for quote).

I have enough PCBs to use as a boat anchor... and I can't bring myself to throw them away. Perhaps they're of interest to others.

I'll leave this up with a bump or so a week until Jan 31. After that, any remaining boards will likely head to the landfill. I'd also love to hear creative ideas for their use or disposal. I'm keeping at least an iteration of each for sentimental purposes ... and "art".

Let's start with a few that could be very easily used.

• Pair of store Aleph J boards. $15 plus actual postage. I bought them from the diyAudio store. I think they're $25 normally...?
• Pair of "prototype" Aleph J ZM boards that work perfectly with no modifications. If you're familiar with the project, you may already know the boards. Black, ENIG. $10 plus actual postage. If you've got some 150s and a few JFETs lying around... this may be for you.

Then there are some boards that can be a little less easily used, but are still perfectly functional. What I mean by less easily used... The boards themselves are perfectly fine, but some amount of sleuthing may be required to determine the exact iteration and match to a schematic. Easy for seasoned builders. I've built with all of them. I will not support any of them in any way.

• 5 Sets (10 boards) of Blue / HASL Iron Pre Balanced "2020 rev 1" boards. $5 per set + actual postage
  • Perfectly fine "through hole" version of the balanced boards. May be a wonky trace for the Edcor transformers?
• 1 Single Green / HASL Iron Pre Balanced "2020 rev 1" board. Free + Postage
  • Same as above. Just green
• 1 Iron Pre SE "2020 rev 1" board. Free + Postage
  • May be a wonky trace for the Edcor transformers
• 1 Iron Pre Balanced Blue / ENIG "2021 rev 1" board. Free + Postage
  • Just an extra board. It's flying solo, and we've moved to the SMD version.
• A bunch of blue and green Iron Pre "Twister" boards. Free + Postage. These are the original twister boards for those that may want to use them in a build.
• A bunch of V.3 blue twister boards. Free + Postage. These are the V.3 version (latest version), but they're blue. We've moved to black.

Then there are some boards that can all work, but may need some love and/or an adventurous builder to find and match some parts etc. These may be art projects, or ... someone may want to give them a shot as a build. Again, I've built working projects from all of them. I can provide (the intended) schematics and some advice for those that may want to build with boards that otherwise may become an art project.

• 4 Iron Pre SE V.4 SMD boards. Green / HASL. Would need a small rerouting of a trace. Free + Postage. For anyone that actually wants to build with them, I can show how to reroute the trace.
• 8 Sets of Iron Pre Balanced V.4 SMD boards. Green HASL. Perfect boards for an ambitious builder that can get matched 2145s and solder them. $4 per set + Postage
• 7 Iron Pre V.4.1 SE SMD boards. Green / HASL. Perfect boards. Same as above re: 2145s. $2 per board + Postage
• 2 Sets of Aleph J ZM V.1 proto boards. Green / HASL. Perfect boards. If you want to try paralleling some JFETs... these are for you. Meant for through-hole J74 / J270 (or whatever you'd like to try) parts. $2 per set + Postage
• 4 Sets of Aleph J ZM V.2 proto boards. Green / HASL. These need some fairly tedious surgery... after that... they're marvelous. I'd recommend only for artwork. Free + Postage

I hope some of these find homes outside a landfill.

Thanks for looking.

Edited to add - to remove some tedium re: shipping. Please don't ask me to quote you shipping. Use a site called Pirateship.com (or similar) to see what shipping from US zip 55372 to you for an 11" x 9" padded envelope weighing ~6oz would cost to your destination. That will get you in the ballpark. If you're serious after that, we can go from there.

Fully recapped
Serviced
New speaker protection relays ( original nos )
New fuse holders

Early John Farlowe era
In fantastic cosmetic condition and perfect working order.

£500 plus p&p ( uk based ) 240v
No offers

I have a Sony TTS-4000 direct drive turntable that I purchased for restoration. I'm moving in September and need to make room (we're downsizing). This is sold as-is with no returns or guarantee. The seller said it works but I haven't tested it. I believe it's complete - i.e. no missing parts.

I did do some research on this table. It's fairly well regarded direct drive and much better than the TTS-2000 I also have for sale. Recently I saw one listed at $1000 (seems a bit high to me). I'd recommend replacing all the electrolytic capacitors - these early direct drives need this done to preserve the early logic.

The armboard clearly needs to be replaced but this is easy since it's a removeable armboard. I can probably make you another one if needed.

I'm asking $200 plus actual shipping cost.

I have several tonearms that could be paired with the table.

So, new here, and with zero knowledge of speaker design, but I know what I like to listen to, and have a reasonably good ear - I can hear when something’s astray, even if I can’t describe what it is.

I recently inherited a pair of KEF 104s (not ab’s) from my Dad, which he bought new when I was a kid, in about 1975. I’ve always loved the sound of these speakers, and almost from the day he bought them my Dad promised they’d be mine eventually.

He had the speakers serviced about 10 years ago, I think mainly the passive radiators which had perished, and the grilles which were foam but are now cloth.

When I got them home though, I found the bass driver in one speaker wasn’t working. I thought it might be the crossover, but swapping the driver to the other speaker proved that wasn’t the case.

The driver is “bottoming out” in its rest position, with what sounds like a metal on metal click.

I can’t afford to have the driver repaired if that’s even possible, so I thought I’d try an experiment;

My previous speakers were KEF Q15s. So I initially took the coaxial driver and crossover out of one of those and tried it in place of the dead driver in the 104 with an mdf “adaptor plate” to make it fit, so basically a Q15 in a 104 cabinet, with the 104 crossover and tweeter disconnected, but with no reflex port.

The result was awful - very harsh, with no bass to speak of - less than in the correct enclosure in fact. The passive radiator hardly moved even at high volumes.

So next I tried the Q15 driver in the 104 cabinet, but with the LF connected to the 104 crossover, and the original 104 tweeter connected as well (so the Q15 tweeter disconnected).

Comparing the modified speaker with the working original, I could honestly hear no difference, so I went ahead and applied the same mod to the “good” speaker. The result, as far as I can tell, is a sound every bit as good as the original 104s, and with a very similar characteristic.

So, to the experts here, is this sacrilege? Should I hang my head in shame and leave via the back door? Or have I been extremely lucky and happened to have drivers available that maybe on paper shouldn’t work, but do?

Have I created any issues for the future, in particular with the crossovers maybe?

The mods are completely reversible, so is there something simple (and low cost), that I can do to get the original driver working?

Hi, i bought Haufe RK 270 input tranformer (1:1), for the use between dac & preamplifier.




I have two questions:

(1) -I only now got to look manufacturer datasheet:


Have i understood this right, that it will have frequency range of 40hz-20khz?
So it will not be good choise for this application for whole frequency range?..


(2) -How do i connect rca-connector to it?
Which number do i connect (red signal) wire input and output, and which number neutral input and output (black)?

Do i have to measure it and figure it out, or can it be seen from upper diagram?
Here is picture for easier explaining, thanks!

'

someone says that beryllium diaphragm is better than titanium and make sound cleaner and better but i think this is marketing becase is expensive product. So after some research i found audioexpress page showing Radian 745NeoBe that 118 - 120 db produce 60 - 65 db 3ed harmonic distortion and B&C De980NT-8 WITH 118 - 120 db produce 45 - 50 db 3ed harmonic distortion and also higher frequency extension.

Also you will never see any Top brand use beryllium as L Acustics (Which has excellent sound and not even high presure levels distortion or harash sound...)

... and put it in the closet. It works but is really only for nostalgia.

In its place I put the laptop (even though the shelf is too short to fully open the lid). I wanted to get the laptop off of the floor.

The system looks neater. 🙂
Ed

Hi! New to diy audio, hoping to learn as much as possible. I think Ill start with a dac build. If anybody has any recommendations on where to begin or good beginners resources, that would be much appreciated!

I wish you all Happy New Year!!

I got MQ FS-030 and I’m trying to use it for building a 300B SE amp. I understand this output transformer is restricted to 60mA. All the schematic that I found was operating with 430V on Plate and 80mA with 880R or 1k of Cathode resistor.

If I’m trying to use for the current schematic, what is operating condition for 60mA? What is the plate voltage and the cathode resistor for 60mA operation?

Would you recommend the best 300B SE schematic for FS-030, please?

Would you advise me, please?

Thanks in advance.

K.

I'm experimenting with output inductors on my class D amp (irs2092 based). 6x 4227 output FETs switching around 200kHz. Output stage is more than capable of over 1kW of power but my power supply is the limiting factor so I detune to around 700 watts at 1 ohm.

As others have experienced on here, using power inductors will cause them to get hot. Many people here like to recommend T106-2 as well.

However, I harvested an inductor from a old amplifier that uses double stacked black cores with 17 turns with dimensions - diameter: 30mm, ID: 13mm, H: 23.5mm (height is total height of stacked core) with an inductance of ~33uH. This inductor runs very cool (50C max). What type of core do you think this is? Plugging the values into coil64 program, it seems to have a Mu' of ~30. Whereas cores like T106-2 has a Mu' of 10.

I also tried fair-rite material 68 (https://www.digikey.com/en/products/detail/fair-rite-products-corp/5968002701/8599644) which has very similar specs to T106-2 but it got very hot (over 120C). I wrapped it with about 45 turns of 5 parallel 20AWG wire to get about 40-45uH. Material 68 is NiZn instead of iron powder of T106-2, would this be the cause of it getting hot?

I would like to try T106-2 core but it seems I can only get them on ebay at the moment, ideally I'd like to be able to buy from digikey or mouser.

Hi,

This is my first time here, hopefully I am putting this in the right place. I am trying to get audio out of my buildings door intercom and into my raspberry pi using a USB soundcard, a cheap one from Sabrent.

The USB soundcard has a microphone in port. It is a Sabrent USB soundcard.

Measuring the voltage across the speaker it is about 6.5V, and the speaker is approximately 125 ohm. I obviously cannot simply plug this into the soundcard's mic in port. I am wondering what the easiest and simplest way to attenuate this down to a mic level would be. There's only a few small issues.

On this board there's a relay. Somehow the impedance of the speaker connected impacts the relays trigger voltage. I don't entirely understand how this works. I plugged in earbuds to the newly soldered audio jack which had a 35ohm impedance. When I used my pin to pin adapter and the lower impedance headphones, the relay stopped working as the output voltage of the relay terminals dropped to only 2V instead of the usual 7V. I don't entirely understand why.

My thoughts are to make a voltage divider to bring the line level down with a total resistance of 150ohm, but I don't know what the output voltage would/should be. I don't know if I am approaching this the right way. I have both a ton of resistors and potentiometers on hand, so I am willing to mess around with those.

Finally, I would need to do the same with the output of the soundcard back into the intercom which is expecting a mic level input, I will likely simply reverse whatever strategy I used for attenuating in one direction. I can also use the volume control to help with that.

I really appreciate anybody's thoughts on this, I can try to provide schematics, however I am a mechanical engineer, not electrical so that is not my strong side! 🙂

Thank you.

MB

Hi all.

I am split between making the mk boom from parts express or the isetta speaker from paul Carmody.

I was wondering if anyone has any experience with both and can comment on how the sound quality compares.

Cost and build complexity seem fairly similar in these two build so I'm more interested in the final result.

Hi!
Anyone who heard the DCX464 and DCX354? What are the differences in sound of them?
Which compression driver would be your choice above 1khz for a club installation? The dcx464 or the dcx354?
The driver hast to play over 3x 18Sound 15NTLW3500 (80-350Hz) and a 10" Midhorn JBL 2012 (350-1100Hz).
Crossover will be active FIR with Powersoft Amps. Horn for the Coax is a Limmer 250M.

PRV, a Brazillian Pro Audio driver company makes nice PA drivers, and I recently found out about an interesting offering from their "Woofer" line. The 5MR450-NDY is woofer that may interest some of you as a possible high sensitivity wideband unit. It is labeled a woofer but the spec sheet clearly shows promise as a fullrange driver with highs extending into the 15kHz range. There are two variants: 8-ohm, 0.57 Qts at 95dB and 4ohm, 0.42 Qts at 98dB sensitivity at 2.83 volts-1-meter. Certainly this is not the first 95-98dB wideband driver, but I don't know of another rated for 250 watts RMS with 2 mm of xmax - if you do the math, the max SPL from this driver is pretty high up there and earns this driver, the moniker of "El Rey" for FAST. There is a limitation of course, it cannot produce bass below 200 Hz and as such, needs a helper woofer or sub, hence I qualify it as a driver for a FAST (fullrange assisted subwoofer technology, i.e., 2-way with a low XO) configuration because the fs is about 170Hz to 180Hz. But, this frequency range is about an ideal XO point for a FAST system. If you have an interest in having a fullrange top driver that can light up a room keep reading.

8-ohm variant:
Page not found

4-ohm variant:
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I received the 8-ohm variant drivers the other day (about $105 ea - yeah, I know, I can buy 10 Vifa TC9FD's for one of these... btw, the front view looks just like an oversized TC9FD, down to the front foam gasket and rounded off square frame 🙂 ) and they look solidly built with a nice cast aluminum frame, solid thick paper cone, and a bevy of radially mounted Nd magnet slugs, and a vented pole piece for good cooling. The suspension and cone are very STIFF to achieve the high fs and high efficiency - I could barely get it to flex with finger pressure. There is no whizzer cone, just a stiff hemispherical domed dustcap - which I believe is why this thing works so well at HF's - it acts like a dome tweeter.



I proceeded to mount it to my cardboard test OB "Cheap and FAST, Literally" setup after making a new foam core adapter plate. Here is a photo of the setup. The driver is offset so that the center is 5 inches from the side and 5.5 inches from the top in a 12 in wide open baffle with small wings on the back. I hooked it up with the mic on axis at 1 meter away and took this measurement:



Here is the factory frequency response data:



I was really shocked by how good this measurement looks, and I think that you will agree that may even be smoother than many a more expensive 95dB class full range drivers out there with names starting with an L or F. None of them will match it in SPL capability. Many folks will be perfectly happy with 15kHz highs, and a helper super-tweeter can always be added for more "air". The bass starts falling off at 340 Hz here, and that is consistent with a 12 in wide baffle with a one inch offset mount.

For a simple yet high SPL capability, high passing at about 230 Hz (in a 6 liter sealed box) lets you put into it a solid 200 watts RMS for 113dB SPL (xmax limited), and still stay below the 250 watt thermal rating. If you front-horn loaded it, you can get some amazing SPL's in the 120+ dB range. Here is the prediction of the SPL in a 6 liter sealed box (Q=0.707) with 35 volts rms of drive:



I did not have time to set it up in a FAST with a woofer yet, but did manage to listen to some test tracks where I knew what the sound should be like above 300 Hz. It sounds very nice and articulate, smooth, and an amazing level of detail and sparkle from heavy paper coned PA woofer. Snare drums, high hats, clicks, drum rim shots, all were present and sounded good.

If you want extension down to 100 Hz to pair with a traditional non-directional "sub-woofer", alignments like a bass reflex, MLTL, even BLH can be employed and they have the advantage of being rather small as only 100 Hz bass extension is needed.

I will add more predictions in other alignments and if anyone else has some experience with this driver, please let me know how you like it.

Edit: this driver can be used in a 300Hz to 15kHz tractrix horn too. Here is the response and harmonic distortion (which is very low).



Here is the horn:



Edit July 24, 2021: Recent detailed measurements in Hypercube here:
PRV 5MR450-NDY for FAST/WAW applications

I read that converting the 12AU7 sockets to 6FQ7/6CG7 is a great sound modification. I see that Ebay sells several of these adapters and all of them specify 6.3v heater voltage. Does this mean one must drop the heater voltage when using these adapters or does the adapter do this for you? They all come from China so I am loath to try to get an Engli9sh answer from them.
Here is an example:
https://www.ebay.com/itm/1920854637...hcTrqRbdrCphJ1/f17eH1LWKQj|tkp:Bk9SR8bl18aXYw

Thoughts?
f1jim

hello, I am converting a bluetooth speaker into a wired one (dont ask why lol)
I need a datasheet to find the input pins of the amp, to connect my aux cable to. the (TK0373E. )
I saw a post on the TK0577E where somebody said its the same chip as the PAM8406 stereo AB/D amp chip which has a readily available datasheet
link: https://www.diyaudio.com/community/...-any-information-about-this-music-box.357252/
can anyone help me find what chips are the same as the TK0373E so I can get a datasheet?
many thanks

I've been playing around for some time trying to find the best way to mount (or not) my DML panels. Recently I've noticed that using the wavelet spectrogram in REW gives an interesting perspective. The wavelet spectrogram reveals some things about the time domain response that the regular frequency response does not. (Thanks @homeswinghome) In particular, it seems to be pretty good at identifying which frequencies continue to reverberate (i.e. ring) long after the signal has stopped.

Below are the wavelet spectrograms for the same plate mounted three different ways. The plate is a sandwich composite with carbon fiber/epoxy skins (0.25 mm) and balsa core (1.6 mm) that is approximately 406 mm x 584 mm.

In the first case, the panel was suspended from wires attached to the panel along the top of the long side, at about 130 mm from either end. This condition roughly approximates a free boundary condition.

In the second case the panel was mounted to a rigid wood frame using squares of a 3M double sided tape (about 12 x 12 mm) spaced about every 50-75 mm around the entire perimeter. This 3M tape is called 3M Indoor Mounting Tape and is about 1.5 mm thick with adhesive on both sides. I believe the foam substrate is a closed cell polyethylene. This foam is quite easy to compress, and rebounds quickly when you stop squeezing. This condition rougly approximates a simply supported boundary condition.

In the third case the panel was mounted to the same frame, but this time with continuous strips of EPDM rubber, about 10 mm thick and 20 mm wide. The strips ran nearly the length of all four sides with the exception of about 50-75 mm from each of the four corners. This foam is still soft (though not as soft as the 3M) and rebounds more slowly than the 3M tape. This condition also roughly approximates a simply supported boundary, but with a bit more constraint than the previous condition, and hence slightly higher natural frequencies.

Here are the REW wavelet spectrograms for each of the three mountings (1/6 Frequency resolution):

Wires



3M Indoor Foam



EPDM Foam


Note that with the "Wires" suspension, there are a large number of vertical lines in the spectrogram, indicating a large number of natural frequencies that continue resonating (ringing) long after the original signal. This I would consider not to be a good thing. Also note, however, that the SPL level of these resonances is relatively low in comparison to the initial signal.

With the 3M Indoor foam mounting, there are fewer long resonating frequencies. But wow, some of them (like at 200 and 400 Hz) ring with an SPL similar to the initial signal. Probably also not a good thing. Maybe even a worse thing than the Wires mounting.

On the other hand, with the EPDM continuous mounting, the only clearly resonating frequency is the fundamental. This, I believe, is a good thing. I feel pretty sure that the reason for the difference is the damping effect provided by the EPDM foam compared to the PE foam and the free edges.

Is anybody else using the wavelet spectrogram to evaluate their DMLs?

Eric

Hello, friends, I have been asking for your support to obtain the values of the RFA4 and RFB4 resistors, of the input card of this amplifier, a big hug and have a good end of the year and happy new year.

Hello everyone I’m a new member with some knowledge of electrical, but the wrong kind.

I have a onkyo tx-nr807 receiver that I was playing the music way loud a few years ago and it turned off so I came back inside and turned it back on and as I walked away, it was shorting out sparks everywhere. I unplugged it weeks later it took it apart, took the screw out of where it shorted in the transistor? I believe and plugged it back in. Turned it back on and poof. A capacitor went . I left it and forgot about it.

Now I am off work for a long time because of an injury and I’ve taken it apart but I’m at a point where I need to order parts or figure out what to do and I’m looking for a little advice or lead me in the right direction.

I’ll post pictures that I have taken thanks

As NEW AURALiC Taurus MkII Class A headphone amplifier in original factory box with instruction manual. One of the top sounding HPAs. Well regarded with many excellent reviews on the web. Balanced & unbalanced inputs/outputs. Barely used with no issues at all. Just downsizing in my retirement. $895 and split the shipping & insurance costs. Please pm if interested.

Sold "as-is" and no warranty is expressed or implied. No returns or refunds. Sells and ships to continental USA residents only. No APO/FPO addresses.

Hello everyone!
Despite being new here, I've immersed myself in the world of audio for quite some time. Currently, I'm engaged in crafting a custom 8-inch woofer and find myself in a cycle of tweaking components to find that sweet spot. I'll be sharing a DATS v3 file and the WINISD recommended box volume. My objective is to achieve a flat response reaching down to at least 40 Hz, all within a box size of 25-30 liters. Could you kindly guide the specific parameters to adjust in the woofer driver design to meet this goal? Your assistance would be greatly appreciated!

I’m trying to better understand solid state circuits; it’s a journey.

I’ve attached a schematic from a vintage receiver - a Pioneer SX-880. I’m hoping someone can explain how the regulated voltages are set. Let’s take the positive regulator, Q28 and Q30. Q28 I think I might understand. 14 volts is needed elsewhere in the circuit so the 62k resistor and 14v diode sets the emitter voltage. The 15k/8.2k divider sets the base voltage. I’m not sure why we need the D25 diode, perhaps to keep the operating point stable.

Q30 I don’t understand. It’s intended to set the regulated voltage at 41.5 and so the base needs to be at 42.1v. So how is that base voltage set? Q24 sends 2ma of ripple to the Q30 base for noise rejection. That doesn’t set the voltage does it? What does? Is it the conductance though Q28? Is the operating point set by diode Q25? These are just guess on my part. Please, someone splane it to me.

Selling a SissySIT amplifier

Expertly built by a member here on DIYaudio, great sounding, only selling because I have too much stuff!

500va toroidy trafo 230Vac
Teabag PSU board
Thf51 matched pair
400 deep amp 3U modushop
Cinemag CMOQ-4 high nickel trafos

Amplifier is in Belgium, will ship worldwide

A rare vintage active preamp made by Sondex ( John Widgery of Radford )

Working perfectly though I haven’t got a TT to test the highly regarded phono stage.

£150 plus p&p ( I’m uk based ) 240v

Hi everyone.
I am looking for a schematic diagram for an old TAC KT88 push pull amp. Specifically the one with ecc83 in front.
I have been searching for some time and can’t seem to find one anywhere.
Hope someone here might be able to help.
Thank you very much and a happy new year to everyone.

I just acquired this amp from a neighbor who says it is not working and wants me to repair it, if I can. It powers up but seems to make some clicking noise. I checked the DC offset and the AC ripple and they look okay as this unit has transistors in the output.
After opening it up it appears that someone has worked on it, making any repairs on it difficult if not impossible as you do not know what was done.

Does anyone know where I can get a schematic for this unit and at least give it a shot to repair it. I am assuming the tubes are good as I do not have a tube tester and trying to find someone who does is like pulling hen's teeth...

Any help is appreciated. Have a Happy New Year to all.

Cheers Wayne

I just completed building the 8600s.It has all top of the line componets including WE 300B's. It took me about 50 hrs to complete. I took my time and paid very close attention to soldering ! The kit was well packed and organized. The instructions were excellent and very easy to follow ! Victor has been a Saint ! That man is dedicated and very professional ! He was always very prompt in responding to any questions !
The final step are the voltage checks ! My test results were all within spec but I had no left output ! I could not find any issues after inspecting several times ! Thanks to this forum and found a thread that described this very same problem. The ALPS potentiometer had a very tiny solder thread on unit 2 CN308 GND and L1 (left channel output). Problem solved !
If anybody runs into the issue of all voltage checks in spec but no output (could be either channel) check the ALPS connection soldering points ! They are very close together !
This is a fantastic amplifier and fun to build ! My first ! Happy New Year !

I have an old Kenwood KD-491 turntable and just replaced the turn belt. When I try to play my albums on 33 speed the speed is to fast. It only has 33 and 45 selectable speeds. does anyone know how to resolve issues?

I've noticed a lot of audiophile tube schematics with no grid stop resistor in the circuit.
Do they know what its really used for?
Why do they omit this important piece?

This is the head amp - or pre-amp if you prefer – you will need for Panasonic Strain Gauge Cartridge, the most common model being the EPC 451C. The legendary Panasonic Strain Gauge cartridges sound incredible, but unless you have the CD-4 or a custom made amp you can’t use them. Most of the CD-4 units you’ll find out there are good for parts or really in bad shape, maybe they’ll power up. NOT THIS ONE. It’s been bench-tested by an experienced audio engineer and serviced. I’ve been using it and it sounds great with my EPC 451C.

Price: $249 firm . I will take Paypal. Buyer pays shipping and Paypal fees.

DiY dây tín hiệu bosse 9pin


Please try posting in English.

Google Translation:
DiY bose 9pin signal wire

Twisted Pear Buffalo-IIISEPro28 DAC for sale - board only, no regulators or power supplies. Box is unopened. Retail $299; asking $200 + shipping. I bought this and then decided not to build it.

For not so disgusting. (APEX A40) 😎

Hello Everyone,

Its been 13 years since i started to build guitar tube amps, i have done few things as 50W 100W PP 6L6GC single, dual channel, EQ, dual EQ, more amp EL84, EL34, EL95 6AK6 etc...

I'm looking to build for the first time an HiFi one, a PP of KT88 UL and i'm sure i will find some help here 😀

Best regards,
Alexis

Hello,
If I want to replace the woofer in the old ALTEC A15-8A, do I need to replace anything else ?
Sorry, I'm a beginner !
Gwenael

Hello,

I have for sale the following pcbs:

1x power supply(the first one that hosts the transformer and regs on the same pcb)
2x gain stage
2x buffer
2x encoder
1x subwoofer

The pcbs are 1oz copper gold plated and come from the UGS Muses group buy.

For the gain stage pcbs I have also the resistors(dale).
For the subwoofer board I have all the components.

Sold

NLA

For fun I decided to test a small glass of salt water for linearity as a resistance. The electrodes were strips of stainless steel (in fact the spring strips from old windscreen wiper blades!). This was added to a divider circuit with 680 ohms as the lower leg. My QA403 was used to plot various aspects of this resistor's performance:

At the standard 1kHz the typical distortion v. level curve shows up:


The linearity increases with frequency:

This might be due to impedance falling, or polarization or perhaps something else (scope for further investigation), I forgot to check if the gain varied with frequency

Seems to be mainly 3rd harmonic (makes sense as the cell is symmetric):


Residual at 60Hz:

A beautiful and well made Power Strip. Hospital grade outlets, star wiring with Belden 19364 cable.
Thought I'd change to US type connectors and there is more to choose from - but never did...

Offer something reasonable (shipping added).

Go ahead 😊
Cheers and happy 2024!

P.S. Did you know, that in some parts of the world, they are getting very close to 123123?

Hi!
New member here.
Dunno if this is the proper place to ask but here we go:
I have a Denon Heos 1 network speaker where the rechargeable Go Pack no longer seems to charge properly.
It indicates full charge but won't power the speaker if I disconnected the power supply.

So I wonder if anyone tried to take a Go Pack apart and if it will contain a standard battery pack that can be replaced.

I new Go Pack is of course available but they are a bit pricey...

Thanks in advance for any input!

Have anyone tried Broskies tube crossover? the information on the glassware site is spars. I particularly wonder if it is unity gain ore a gain adding linestage? I already have an octal tube preamplifer with 6sn7 and I would like to keep in my system.

My second quastion is how does a phase adjustment cuircut look? like the one many plateamps. The 6-24 biamp crossover (nelson Pass) ore the aikido haw this.

this will be a part off 3 ore 4 way system with activ crossover beetwen a bass and midrange/ tweeter.

Dinosaur here,
I know that they started doing this when flat screens came out and everyone
just uses their remote, but sometimes you do not want to find your remote
and just turn on your TV. IE just push where the light is!

Or to give you enough light to find your remote.

Just ranting.

Hi guys,


I was wondering if anyone could help me with a Diy crossover + enclosure
suggestion for a 2-way system, tuned for HiFi home use with:


Eighteensound 12W500 - 12 inch woofer
+
Eighteensound NSD1095N HF compression driver + XT1086 Horn



I'm building something like the Unison Research MAX-1 (not the looks, but
the overall enclosure size etc.):


Unison Hifi, High End - Malibran - Lautsprecher (german site, with review links)

Max 1 - Unison Research - Official Website (official English website)

It seems that (although in one review it says, wrongly, a 12W700 woofer
is used) a 12NLW9300 woofer is used combined
with the XT 1086 Horn. I guess the HF also is probably something like a
NSD1095N because it is the top model 1 inch driver from Eighteensound,
next to the ND1090 (to be fitted with 1 inch XT1086 Horn).


I also found some examples at the following websites:


http://www.eighteensound.it/Portals/0/EnclosuresKits/18sound_12%202ways.pdf Don't think this is
particularly tuned for hifi purpose.

A Finland website:
Kaiutinrakennusohje - Nitrosäiliö - 15-tuumainen hifi-PA-kaiutin | AudioVideo.fi


Same website, different pages translated with google (for what it is worth):

15 inch plan:
https://translate.google.nl/transla...ailio-15-tuumainen-hifi-pa-kaiutin&edit-text=


15 inch plan with crossover renewed:
https://translate.google.nl/translate?sl=fi&tl=en&js=y&prev=_t&hl=nl&ie=UTF-8&u=http%3A%2F%2Faudiovideo.fi%2Fopas%2Fnitrosailio-kaiutinrakennusohjeen-jakosuodinpaivitys-ja-ulkoasumuutos-mikkelin-amk-muotoilun&edit-text=

12 Inch plan:
https://translate.google.nl/translate?sl=fi&tl=en&js=y&prev=_t&hl=nl&ie=UTF-8&u=http%3A%2F%2Faudiovideo.fi%2Fopas%2Fkaiutinrakennusohje-dynamiitti-12-tuumainen-hifi-pa-kaiutin&edit-text=


Also interesting PA Diy kits at DiYsoundgroup:
Maximus-12 DIY Sound Group

And high priced PA pair Yamamoto YS-500:
6moons audio reviews: Yamamoto SoundCraft YS-500

Basically i'm trying to see if anyone already build some reasonable 2-way
system with a 12 inch combi with the NSD1095N. It seems to be used now
and then in hifi surroundings.

I already ordered the HF driver but the woofer i could still change, but
i plan to keep it with eighteensound.

Links to other threads with 2-way PA hifi speakers etc. are welcome!

Thanks!

Have focal midbass and tweeters up front with crossovers and focal 2 way in rear. Want to use head unit for crossovers. How do I determine highs, mid highs,mids, mid lows when headunit says front and rear? Pioneer nex 440

Up for sale are 4 pairs of the rarely offered V-Fets Yamaha 2SJ26/2SK76. nos, unmatched but all checked.

Excellent for someone who has to repair a Yamaha B2, or just for building an amplifier.

All 8 for Euro 500, shipping and PayPal fee in Europe included, outside Europe I like to add the necessary additional shipping fee

Mike and company have closed (here: http://www.fourwater.com/) and our community is a little smaller. 🙁

Always helpful, knowledgeable and courteous - and will be missed. Lots of useful information on the archived pages - get it while it's there.

Hello all. Would like to share my new project build. This is a prototype for my Bass and Synth amp as well as a small but potent PA speaker focussing on a musical sound delivery. Inputs will be my tube based Uf'fornica preamps, tone and summing amp and headphone. The power amplifier boards are well regarded commercial class D units from forum member Erica.C and contain a built-in mains power supply and features aux power outs for fans and preamp. Driver setup is similar to 2.1 and based on a pair of 3" full range drivers and a single 10" bass driver

Max cab size is fixed to 50 cm x 35 cm x 35 cm

The drivers themselves will be chosen after auditioning a few units from various brands