Inside is a field coil made by Lowther UK

https://www.facebook.com/groups/lowthermodificationsupportgroup/permalink/1514513875767329/
https://www.facebook.com/groups/lowthermodificationsupportgroup/permalink/1514515712433812/

I am interested in measuring the vas of a speaker. I have looked at a few articles and they've said to build a box about the dimension of the. speaker as a cube. However, I feel that there is some incompleteness in the description of the process. I presume the speaker then gets screwed onto the box upside down. What doesn't seem to be explained is where exactly the measurement is made with the microphone. Maybe I'm missing something obvious. My apologies and thank you in advance for any help in this matter.

I have a USA-100 amplifier that has no audio output. I have rail voltage amp powers on and was wondering if anyone knows if the relay is for the audio phase?

I have a just bought a pair of Mission 782, which are decent Made in England 3 way speakers from the 90s, with a famous fatal flaw. The Audax made Keraform mid drivers all suffered corrosion on the coils from the glue they used reacting with the solder. It is terminal, and these ones are no exception with 2x dead mids.

I have ordered 2x Audax HM130Z12, which I have been advised are excellent replacements of much higher quality, although I am told they will require a bit of routing to make fit, which is no problem for me.

My question here is whether they genuinely are drop in replacements electrically, as the sensitivity seems to be lower than the earlier Audax HM130Z0 that Mission themselves used to replace the failing Keraforms.

The original (Mission branded) Audax Keraform 82-LF130/QS had a sensitivity I've yet to unearth. I can't find a datasheet online, and all surviving units seem to have failed due to coil corrosion.

The Audax Aerogel HM130Z0 that Mission used to replace these dead units has a sensitivity of 92dB

The Audax Aerogel HM130Z12 that I've ordered (as some say they are an improved version) has a sensitivity of 87.8dB

I'm guessing I may end up with a more laid back midrange than is optimal. Is that likely? Would I then need to attenuate the tweeter and bass drivers to flatten the response? What's the best way of assessing this?

Many thanks
Lucas

Im building the Elektor preamp with the canned MAT-02. So the layout on the board is for the TO-78.
The newer versions are in DIP format. does anyone know af an adapter to go from To-78 (on the PVB) to DIL 8 on the adapterboard.

Just done up today, one set of complete and tested Miro PCM63 DAC + JLSounds i2sOverUSB stack.
In my opinion, this is the most direct and best combo implementation of the Miro PCM63 DAC.
Sounds wonderful. It is a full, completed DAC, with a pair of AD797 op amp for the IV.
All resistors are smd, except the crucial IV resistors which are special high grade Vishay GSR.
https://www.vishay.com/docs/66004/gsr.pdf
Check their prices at Mouser by entering Vishay GSR. They cost $20+ a piece, with a MOQ of 25.

You need +5/-5V and +5/-5v directly to the DAC board. The JLSounds board's 'dirty side' is configured to be powered by the USB Bus ie. drawing +5V from your USB source. This can be changed to be powered from a PSU of your choice if you wish. Can be done very easily by cutting a pcb track under the JLSounds board as instructed by the user guide, and then soldering two wires from pads available on the DAC board out to the PSU. The XO and reclock circuit of the JLSounds is drawing +5V (digital supply) from the DAC board when you stacked and isolation from the USB 'dirty side' is achieved. Very neat and clean design, with full isolation achieved.

Case it up with transformers, PSU, connectors, a pair of op amps , connect it to a USB music source and you are ready to rock and roll.
All high quality parts are eg. Nichicon gold caps, Wima film caps etc etc... See the pics.
All parts are BRAND NEW including the PCM63P-K chips. They are installed for the completion and testing to commission the DAC.
Even the JLSounds board is delivered yesterday 1 November.

DAC Stack + shipping tracked & registered = USD 365
I am only ready to accept Paypal Family and Friends as payment.
As usual, I will also buy Miro some coffee as a token for his generous sharing.
I have shipped 58 packages to members here to US, UK , asia and Europe, not a single glitch so far.

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

Information of the JLSounds i2soverUSB board. This is the USB interface that most members agree to be very good for the DAC.
http://jlsounds.com/i2soverusb.html

I built the Nelson Pass TL, with the Pioneer B20FU20-51FW following this plan: file:///home/martin/Downloads/Pass-BOFU-TL-map-300408.pdf

Great bass, I recently added some ESS AMT tweeters cut with a 2Mf capacitor. I will try to cut lower the ess around 2500-3500 hz, I appreciate your suggestions, thanks

I'm using them with Monarchy SM-70 amplifier.
an old thread about TL PASS

Hello folk,

I often usse trade offs for the casing of my electronics with wood knowing not being ideal (hlf sheildig effect of metal case).

So why casing became almost as much expensive than a finished low cost device with the electronic and the guaranty at the same price ?

Seems to me than transport increased fees is not the only culpritt ? VAT, well 20% averaage here in EC ? What else justification ?

So what else ? It is very no technology but is expensive (hifi 2000,, etc) !

For sale is 1 pcs of Fischer 56 200 SA black anodized heatsink.

Width: 300mm
Height: 40mm
Plate thickness: 10mm

Thermal resistance: 0.3K/W



Price is €80,00 with free shipping in Europe. Payment via Paypal.

I'm wondering if anyone might have Volumes 1 and 2 of the Audio League Report (1954) edited by Julian Hirsch which they might be willing to part with or have scanned?

All expenses met of course.

Hi guys

I am working on an Amp that went to another tech who did not complete the repairs. All the drive ICs have been removed. He did replace the power supply and output fets

Could someone please let me know what drive ICs to use here? Thanks Guys

Hi all

I've found this link: Audio Total Harmonic Distortion Analyzer for LTSPICE, making THD vs. Amplitude and Frequency sweeps in LTSPICE | Audio Perfection


I'm trying to understand how to use this script properly.
Can someone tell me how I can plot the THD vs freq graph?
After I've simulated the given example , I went to the error log (CTRL-L) and than I right clicked the log window.
THD vs output amplide graph appear after I select "plot selected meas data"
I have even changed the analyzer_controls.txt commenting the amplitude sweep and uncommenting the freq sweep but the result doesn't change: I cannot display the THD vs freq graph I'm looking for.
Cheers

Hi, not sure if anyone else here is interested in modding cheap DACs for optimal performance, that's my main hobby. Might participate further and build a nice NOS DAC though. Thanks!

I have built a couple if Bottlehead tube kits, and have a 300B project in the drawer in parts... Nowdays I mostly tweak my turntable and vinyl system. I like to do measurements in order to understand what is going on. I use a KT88triode coupled tube amp as headphone amp, using a APPJ adapter, I plan to optimize it with some mods.

Heya! I'm just some random person who decided that designing a microphone might be fun..? I've had basically no previous circuit designing experience or anything of the sort - it's interesting to say the least. Was hoping that someone could take a quick glance at the schematics maybe. It's been pretty fun!

Hi all,

Just join this forum.

My old Onkyo CD-Player, RC-625C, is not working recently. After placing CD on the tray and closing the tray, no indication showing on the LED display. After pressing the "start key" on the remote control a while, no CD Disc showing on LED display.

I have opened the CD-Player case and cleaned the LASER light with alcohol. Problem still remains. The LASER light holder can move on opening and closing the tray. But there is no light showing. Can I see the LASER light with eye?

Please help.

Thanks in advance.

Regards

I'm trying to fix my late 1980s B&O tape deck which was stored in my attic for over 20 years. I've replaced all the belts and the mechanical side works fine. But, there is no sound coming from the left channel. Initially I thought it might be a capacitor issue so I tested them all in circuit and found a couple of bad ones. I replaced them but still no joy.

I then checked the tape head. I connected a multimeter across each channel and found the right channel reading about 280 ohms but the left channel was open. For each channel I then connected the meter to an output and ground and played a tape. Both channels produced about the same millivolts, zero to about 5. I am now confused why there is an output from both channels.

Is the millivolt output a red herring and the true test is the resistance?

I've also swapped the channels over inside the tape deck and don't get any sound, left or right, which obviously indicates something else may be wrong with the left channel circuitry.

My thinking is to buy a replacement tape head from eBay and then start to troubleshoot the left channel with a head I know works. For all I know, just swapping the channels over may cause another problem which manifests itself as no sound. I can't think what, but as you've probably gathered, I'm fishing for answers to what should be a quite simple thing to fix.

Hi,

Can I have some opinions here please. I've seen a used pair of JBL k2S9800 speakers for sale for a similar price as what it would cost me to build Troels TL3. I've heard the JBL speaker at a hifi show a few years ago with Mcintosh electronics and it sounded fantastic, although there was ever so slight a bit of high end sharpness that I might find irritating long term.

I like TL3 for the speaker attenuation and the hypex amp, but how would they compare. Would TL3 be in the same league as the JBL?

I have this ubiquitous tiny DAC box. Just out of interest I would like to know what the DAC chip is. So I can look up specifications and such.

The large chip at the bottom side of the picture is a MS8416. This is the SP/DIF to serial audio decoder. The small chip at the upper half of the picture must be the DAC. The number 344C4042 does not hit anything.

General Transformer Sales Co. Ltd. now offer an international mail order service.
Payment by PayPal
Web site : gtrans.co.jp.
Their standard line is now discounted.
Finemet, Hashimoto and Iso transformers are made to order.
Use Google Chrome to translate from Japanese to English.
At the top right hand corner of the homepage click on contact.
A page will open and you can type in your request in English.
After that click to translate to Japanese, then click send in Japanese.
They will reply in Japanese and you need to translate to English to read.
Service is prompt.
They have a shop in Akihabara Tokyo.
It is run by old folks and is open only 3 afternoons a week.
If you are in Tokyo you can visit the shop, buy your transformers and save on shipping.
How ever they no longer stock Hashimoto and Iso transformers in the shop because of slow sales.
You need to preorder before hand.
I have visited their shop a few times and have recently purchased a pair of transformers by mail order.

SHAEK-BARE.PNG: I came across this "Shaek" clone of the Radio Shack
276-150 on Amazon when looking for something else. This YUNGUI item
was in Circuit-Breaker-Panels, not electronics. It is not very good
for soldering because the holes are too big for 1/4W resistors and
such. However, the layout is interesting because it has power rails
centered and there is room on each side of DIP sockets for related
resistors. This layout is logical and efficient. Such prototyping
boards are rarely seen now because they are mostly designed as
companions of plastic breadboards with 5-nothing-5 holes and power
strips on the sides.

SHAEK-ROUTED.png: Veroroute models vertical/horizontal stripboards but
does not have a model for hybrids. In fact, it can be used for any PCB
structure with standard spacing for holes and vias. A circuit can be
"painted" manually but I use the autorouter and add symbolic wires or
pads when auto does not go my way. I add a row of pads at the top to
mark how the strips are partitioned. Non-functional circle-X symbols
help to trace track alignment. See SB-ROUTED for more details.

SHAEK-TOP.png: I wired a small HeadAmp with two opamps plus linear
power supply(+/-12vdc) on the Shaek board. Everything fit when
planned using Veroroute. A headphone test revealed a rising high
frequency response probably from the unshielded external volume
control wires. A 100pf cap to ground pin 3 of the 4556 can produce
normal sound. The stripboard version has this fix. See SB-TOP.

SHAEK-WIRES: The holes are too big for the resistor pins. I had to
bend component pins to insure connection before soldering. There are no
interconnect wires on the copper side.

STRIP-LARGE.png: Stripboard or Veroboard has long, parallel strips of
copper which must be cut and/or bridged to create circuits for
electronic devices. This is easy for trivial circuits but becomes
difficult as complexity increases. Circuit tracks must be cut
(Carefully) with a 5/32 drill bit or sharp knife. It is easier, using
the Radio Shack pattern, to make vertical cuts (for partitions) across
all the tracks at once with a fresh hacksaw blade. See SB-WIRES and
SB-ROUTED.

SB_TOP.png: I was inspired by .Douglas.Self:Small Signal Audio Design'
chapter one which had a low impedance drive for tone control
circuits. It was not in the headphones chapter but it can drive them
with a suitable opamp such as 4556. Since the 4556 version merges gain
and buffer functions, there is no need for another opamp gain
stage. This is about using stripboard partitions, so a small but
usable circuit is satisfactory for demonstration.

SB_WIRES.png: First a 19-hole section was cut from a wide
stripboard. Then the copper was gently cut vertically with a fresh
blade to reveal two strips for the DIP sockets and separate strips for
the adjacent components. So there are four partitions. There are a few
spots where a copper cut is not desired and a jumper is installed to
"uncut" it. But this is less complicated than making random cuts on a
large stripboard. And stray capacitance should be reduced. There are
no wires on the copper side and the top wires are perpendicular to the
tracks for minimal coupling.

SB_ROUTED.png:

I add a row of pads at the top to mark how the strips are partitioned.
There are copper cuts at 4, 10, and 15. Non-functional circle-X
symbols help keep track of the vertical copper cuts.

HA-LITTLE.png: KiCad Schematic of "mother's little helper". There is a
schematic note "added C7,C8" to remedy spurious feedback or
instability from my crude setup wiring.

KI-PCB.png: Simple 2-layer layout of HA-LITTLE. There was a problem in
my routing attempt where I needed to use a via but could not get that
to work even after I watched a video where it was easy. So I redid the
routing to work with only two layers.
,,,

This is my first time trying to layout components onto an aluminum board, which I will CNC myself.

I'm interesting in what tips, rule of thumbs, etc, do others use when laying out components to be mounted to an aluminum plate.

In this particular case I'm laying out a modified version of Matt Renaud's Universal S4 pre-amp. I've added a DC regulator for the 12A*7 heaters and a cathode follower with a switch between it and gain. I now have more stuff than the original and need to modify the layout.

Thanks,

Hi everyone,

I have ZR360 on my bench as a learning exercise. I’ve found a couple of TIP transistors that are bad and a couple of sad transistors appear to be shorted. I’ve seen references in some posts here to notes on repairing these amps and potentially service manuals for some ZR amps. I’m hoping someone will be kind enough to share them with as I think they would help my learn process. Thanks.

G'day. I live in the Sydney area. I have an older Fender Rumble 30 bass amp that has stopped making sound; troubleshooting revealed the power transformer is dead. I have scoured the internet for a replacement part, to no avail. I am now looking for a suitable substitute transformer and thought the diyAudio community might be able to help.

I’m primarily interested in car audio. Years ago I competed a bit. I’ve recently rekindled my interest and started a new hobby of trying to repair some older amps. diyAudio seems like a great place to learn more and maybe one day help others when I have more experience.

Does anyone have a schematic of the Dovedale lll crossover please.

looking to upgrade my current DAC board. What s a reasonably good chipset I might find in a relatively inexpensive board? I only need SPDIF. I have both 5vdc, 12vdc, and +-12vdc avalable, Would like a board with a separate op amp output that can be rolled.

Roger

Hi! This is my very first post here. I'm so grateful for all the tips and ideas I've found here over the years, so I hope this post might give a little bit back.
I just finished a monoblock build of 2A3-40:s in push pull fixed bias, with a parallel coupled 5687 as input and driver, via a Tamura A-351 interstage and splitter. The power supply is choke input with a 8H 250 mA choke, but preceded by a small 0.5 uF 1500V PIO cap. Smoothing caps are one 100uF for the output, and two more for the input, all motor run caps.
I run the output tubes at 305V and about 65mA.
The sound is so powerful it's almost scary! It must be because of the choke input power supply, which I truly recommend. All iron is vintage from Japan, which means I use a step down transformer to power them here in Swden, but it works great!

To complete a Collings limiter amp I need a UTC HA-107 interstage transformer

Quayhog53@ gheeeed, male.

Yamaha RX-V2600 A/V amplifier clicking relay sound but does not power up help would be much appreciated 🙂

Years ago I wanted to build a tube amplifier, but lost interest over the years. I have a bunch of transformers I purchased for several projects that I'm looking to offload to someone in Europe for a great price. Most of them came from this site: https://www.ogonowski.eu/

If anyone is interested, drop me a line and I'll put a list together. In the box next to me I have:

1. Power transformer 180W --1pcs

2. Output transformer PP40-G1 --1pcs

3. Output transformer SE25-5 --2pcs

From that site. Those are for a Push/Pull amplifier I think, but I also have some for a single ended I was working on as well.

I'm based in Spain, so these will have to stay in Europe due to cost reasons (they all weigh a lot, so shipping won't be super cheap I don't think).

Hi dears, I have a class D Behringer D1800, the ic 7WH04 may have a problem, when I turn the volume level to maximum it clips, and sometimes it clip without turning up the volume, with the ic in the board, I measured pin 3 with is a output signal and the ground, it measures 76 ohms, can this circuit be damaged?
I would like to know how to measure hex inverters properly. Thanks.

Has anyone ever built a copy of an MT Audio Design XO-2001 crossover?

It was made in Sweden by Matts Tornqvist but is no longer available, the perfect crossover for the QUAD ESL-63/Gradient SW-63 set up.

I do not have the schematic but there are seven ICs in the subwoofer section and two in the main ELS section.

It has many useful functions, two of which are: a pot for setting subwoofer volume level and another (a delay circuit) for phase shifting the sub. A very elegant and noticable function.

I made a new power supply for an MC-101 using 2 separate fuses, one for the low end, 0.125A and one for the high end, 0.5A. The voltages are ok. The 0.125A keeps blowing. Would the 10v AC pull more than 125ma or is it more likely a problem in the rectification circuit? I don't have a schematic (it seems that on one does)

Mucking about since 1965 when parent’s Dual / Shure/ Mac and Bozak system arrived… no furniture… so they taught me the right priorities - music first. I still have the 1961 MC240 ( it was the store demo at Music Unlimited in Cleveland, Ohio ).
Recently acquired a pair of Acoustat Model 2 to spruce up and the acoustatman thread ( a great +’contribution imo ) caught my eye…. So I’m here….
Jim

Hi all. I'm looking at designing my first speaker, and I want to create an LCR type speaker for home cinema use.

To attempt to make things easier, I want to use a woofer combined with a fullrange type driver, crossed over around 500hz using a 1st order xover.

The goals for this speaker are:

1. Be able to comfortably handle 95db peaks in my 4x3m living room (combined with a sub + AVR).
2. Relatively inexpensive - something around £150 in parts per speaker.
3. Maximum height of 65cm externally
4. Simple as possible for a beginner

I want to make an LCR speaker as I'd like some symmetry and matching speakers all round. For this reason, I have figured woofers around 5" would be most suitable as I will need to use at least two woofers per speaker, and the box can't be too big to the point where it won't fit under a TV. This will also help with getting the xover within 1/4 wavelength.

For the woofer, I was considering the 5FE120 16ohm as I believe it can go into a small cabinet vented, and it's also cost effective. I say I believe it can go into a small cabinet vented as I think I've had some trouble simulating on WinISD. I'm getting a bump in the bass response rather than it being smooth when I've simulated other woofers. If anyone could advise on this, that would be helpful. It's also cheap and has a good basket shape for getting drivers close. Link to it here

I note there is a bit of a sensitivty mismatch, even when using two woofers (around 89db for two woofers vs 91db for the 3FE). Would I be able to add a resistor to the 3FE22, or would I be better off seeking a different combination of drivers for the sake of simplicity? There's also a 16ohm variant, could I use that to lower the sensitivity? Without sounding ridiculous, could I use 4 woofers to make up the sensitivity (although this would probably be too big). They come in 8ohm variants, so would it be possible to wire two pairs in parallel and then connect them in a series to make 8ohm?

For the fullrange, I quite like the look of the FaitalPRO 3FE22 8ohm as it has a small diameter, cost effective and I've read some good things about it here. I believe the size is probably a good balance between dispersion and power handling. Link to it here

For the woofer, I'm now looking into an 8" and going with a single unit. I'm trying to find something smooth enough to cross 1st order at 500hz. I am looking at possibly the HiVi F8 as it seems to be smooth past 2k and is only around £50 per woofer. I'm a bit concerned as I've read people say the parameters can be a bit inaccurate with HiVi.

Happy to take any suggestions on other drivers that can be used for this.

I still have a lot to learn about crossovers so it would be nice to get some idea of what I want to do and order some parts to push myself. I always end up putting myself off making speakers in fear of how difficult it is to create a crossover. I really want to learn more though, which is the main goal of this speaker.

Thanks

OPA541AP is an 11-pin power op amp.
It can deliver Peak 10 Ampere and have +/-40 Volt supply.

This circuit can output more than 100 Watt into 4 Ohm and like 55 Watt into 8 Ohm.
Supply is +/-35 Volt DC and the transformer should be 2x25VAC.
At the image is an output of 100 Watt into 4 Ohm.

EDIT: My circuit was not possible. Because of Safe Operational Area.
So I remove this circuit.

I bought this JVC -V711 in 1988 (new)
The cassette is still running well....

Hello,

Recently ordered SA9227 based USB ↔ I2S converter and decided to check distortions of the converter itself making I2S loopback.
The results look strange to me. I expected a symmetrical spectrum, but there is always a horizontal “shelf” on frequencies below the test signal.
I would admit the shelf on the both sides or downward curve on the both sides (of the test signal) as well, anyway a symmetrical curve.
The “shelf” goes down with the test signal frequency increasing and goes up with decreasing.
The “shelf” goes down with FFT size (quantity of points) increasing and goes up with decreasing.
What could be a reason/explanation of such behavior? The converter specifics? The measurement specifics? Something else I’ve missed?

Thanks in advance,
Serge

I have a pair of three-way speakers, ADS L780/2, with damaged cabinets. I’m thinking to install their drivers in my car. But the distance between each driver will not be as original. The tweeters will be mounted on the dash, while the midranges and woofers will be on the front doors but at different corners. So, no point-source orientation as home audio speakers any longer. I wonder if the home audio speakers are installed in a car, can the original passive crossovers be used? Does it require new crossovers or simply need slight modifications on the old passive crossovers?

Recapped ( Mundorf )
Original boxes ( tatty )

Collection in person ONLY from MK5 ( uk )

Absolutely no couriers

£800 to established members

I got my dad's old setup and thought of making it sound better, so why not start with the crossover? It was supposed to be a 3-way speaker, but only the Tweeter and Mid have a (1st order?) crossover. I've been reading this forum on designing a better one, like making those slopes as steep as possible and moving them to a higher crossover order.

Below is the current setup. I managed to get those driver's FRD and ZMA.



It looks terrible to me mainly because all 3 overlaps each other and woofer is playing all frequencies. I used those online calculators to get a "roughly" better crossover and here is what I got

It looks better than before (at least for me), but I need advice from others. This is the best setup I could do since parts availability is a limiting factor (Capacitor from 0.68 to 47µF, Inductors from 0.1 to 2.0, and 3.5 µH)

After 40 years with intense listening and hardware skill development, I rekindled the HiFi hobby a couple of years ago.
Like to find and bring back some old equipment 'from the days', and in general go out and find anything Hifi to bring home and 'roll through' the 2 systems I have, constantly adding new and letting go of old equipment.
Even bought a turntable (no real intensions of using a lot) and NICE (great to look at) reel to feal (Akai and Teac).
Main system in HUGE (volume) room constist of 5.1 (for TV/Movies and SACD) with B&W Nautilus 804 front (relieved of low frequency duty via high pass) and Dayton Audio 18-22 sub in sealed encloser driven by external ED LT1300 sub amp.

Also tinkering with building speakers, and modifying existing (current projects: Kef B139 based 3 way that needs fixing, and Infinity Quantum 2 convesion to bi amp (or tri or quad?).

Perhaps a issue aswered ad infinitum out there...
I have a low cost Bluetooth to IIS board and I want to use with a dynosaur DAC since is fun to play with.
In that case I want to match the IIS board with a YM3433 SRC+AD1860 DAC.
A lot of info is out there, for example: http://www.pavouk.org/hw/modulardac/en_ad1865i2s.html
If I understood well, I need to delay n-1 bits of desired working. In the YM3433 case, I need then to delay 15 bits (since it is 16 bits).
The normal Bluetooth until 4.2 is maximum 16 bits, so is ok to play with.
Since all pages I fond are using NOS DAC, with separate L and R DAC's or data inputs, I deduce the YM will not needs the additional 32 bits delay, since it is channel serial like the I2S (L and R inputs at same pin). This will save parts.

Second, not much related... the YM3433 seems to be a SRC with a unrelated output clock. Not being a digital expert, I only deduce if the output is clocked to a different clock, the incoming jitter will be supressed at some level, perhaps? I'm sure about the ASRC making it, but not about this odd YM DF/SRC.

Will be fun to mix past and almost present if it work. And, I feel this will result better sound than the el-cheapo Bluetooth boards having internal DAC (I hope).

In the past I made a assembly of same board + a ES9023. This have a ASRC and worked flawlessy.

Thanks in advance for any hints/tips/advices. Remebereing, a ultraHi-End here is not the question (I know that will not sound like a direct feed DAC or a high-class Bluetooth solution), is more about the cool factor and the sound hope listed above. And I want to add this to a semi-portable thing I'm will make soon.

I was hoping to get a sanity check on a design I'm doing. I'm trying to build an digital input stage for an amplifier I've been tinkering with the last few years. I want it to be able to read 192kHz/24 bit audio over SPDIF. I'm using the CS8416 chip, but I'm unsure exactly how to connect the SPDIF through it.

I've currently designed it using a 1:1 pulse transformer - the electrical ground in my flat is very noisy, so I feel like this is a good idea. But I'm unsure about the 75R resistor position and the caps on the ground and inputs at the CS8416 (As per the schematic, but the schematic doesn't have an isolation transformer.

If anyone can provide any guidance, please let me know! Thanks. The transformer I'm hoping to use is the DA101C - I'm having a hard time determining if it can do 192kHz though (which I think is 12Mb/s of bandwidth). But it seems to be one a lot of people have used.

Thanks

I recently acquired an AU-9500. So I look in the service manual to adjust the offset and bias. I set the offset ok everything responds as it should. I then follow the instructions and remove the speaker fuse and hook my multimeter in series where the fuse was as it says to do. I fire it up and it says to adjust to 30-40ma. Well its at 10-11ma and turning the pot to adjust it does nothing. It does not change the current whatsoever. Both channels respond exactly the same way. What the F? I cleaned the trimmer and checked it with a meter and it does indeed change resistance when you turn it. So why doesn't the bias change? I have attached the instructions and a pic of my meter clipped in. What else could be wrong that would stop the bias from changing? It even says I do not need any load connected but I tried it with a load and didn't matter.

OPA544T is a power op amp in TO-220-5 package.
It is current limited to 4 Ampere.
With a supply +/-20 Volt it will output 32 Watt in 4 Ohm and 16 Watt in 8 Ohm.
Transformer should be 2x15VAC.

EDIT: My circuit was not possible. Because of Safe Operational Area.
So I remove my circuit.

Retired after a career as an EE spanning over 45 years, including stints at Bell Labs and Intel. Past experience has included digital, analog, and computer design. I'm now looking forward to doing audio engineering as a pastime.

I have this Salas ultra bib for sale pos-neg

inc new print board and the most og the component to solder one more pos--neg

prive 167 euro buyer pay the delivery

3 of these 2 have some black marker looking around the paper surround idk anyways any off I’ll probably take.

Hello! Here's my intro post. Back in the late 80s and early 90s I was deep into audiofoolery. I had much less money then but plenty of connections in the Calgary, Canada area with the people who were involved with Meitner Audio, Highwood Audio and, peripherally, SUMO audio. That gave me access to a few truly talented audio design types who were very generous with their time in teaching me about audio. Then, I got married, had kids, built a house and went to grad school, and all that enthusiasm and knowledge slipped into the past. For a few years I worked as a stage theatre sound tech, and for few years I was an environmental noise consultant who worked all over North America. Now retired, I've revived my interest in music and music reproduction, but most of what I'd learned is gone, or well buried. Along with reviving my interest, I'm also reviving my equipment from that time, which I still regard as very worthy. I also used to build the odd bit of simple equipment. Maybe that will get revived too. We'll see.

My system currently consists of:
A Sony DVD transport that I'd have to go downstairs to get the model number for. Doesn't matter. It's a run-of-the-mill Sony DVD player.
A Museatex PA6i preamp with their upper end phono stage
2 Museatex MTR-101 monoblock amps
I've also got a couple Meitner STR-50s that I might restore, or raid for output devices, but they're not part of my system
A newly made (by me) pair of Troels Gravesen Discovery-4 speakers, that are better than anything I've had before
I just bought a SMSL Su-1 DAC that I'll run the Sony into, as well as music from my MacBook Pro
A dedicated listening room that until recently was an unfinished storage room in my basement. Way back when we built the house (last century) I dimensioned this room to minimize nodal degeneracies. I'm about to try to use REW to guide me towards sensible treatment.

While I still love the music I did back then, (Talking Heads, Davis Bowie, Brian Eno, Peter Gabriel) I don't often like to listen to it much on this kind of equipment. It shows up the production flaws too much, or at least that's the way I feel about it. Now, if I'm listening on this level of equipment I enjoy, jazz, orchestral, chamber and bluegrass. I enjoyed all those genres back then too.

I tend to be what I call an 80% guy, when it comes to audio (as opposed to music). I feel you get further ahead getting 80% to perfection and taking care of everything that needs addressing, while spending 20% of the money, rather than getting all the way to perfection on only some elements by spending a sh%$^-ton of money, but not having enough $ left over to address the other critical factors that also need to be dealt with. Maybe I was a little bit too much the latter when I last tried my hand at this stuff?
I tend strongly towards science, and like everyone else, feel that there are too many snake oil claims to wade through on my way to the best sound and music I can sensibly achieve.

Cheers,

Caerbannog


One of the Troels Gravesen Discovery-4 speakers I just completed

Hi, I own an old Toshiba aurex sc-m15 amplifier. If i listen on low volume after some time one channel starts to change its volume ( sounds even lower volume ) if i increase the input signal it's going back to normal, changing it to lower volume after a while the same happens. [ (This is only the amp, fed from my dac) without the pre amp
aurex sy-c15 that works fine on its own. ]

Maybe some capacitors , I have no ideea what would cause this. A full re cap would be needed since it's very old, but I'm not sure if it's worth repairing. The case ( big aluminium case ) and the transformer could be used to build something different in it.
- Bruno.

I’ll never understand the self-joy someone gets by murdering an innocent wild animal for their own selfish fetish. Go out into the woods and watch the animal all you want. Enjoy seeing him in the nature environment that he is a part of.

But don’t murder him for your stupid and selfish entertainment.

And what’s even worse in this story is the animal was murdered with a bow and arrow rather than a rifle, so it probably suffered even more before it died. This is disgusting.

Sorry but I’m not buying the argument that it’s OK to kill these magnificent animals as long as you eat them. That’s nonsense. You can get all the meat you want by simply purchasing it at a store. People murder them so that they can hang a disgusting trophy on their wall. It has absolutely nothing to do with using them for food.

Leave the wild animals alone for God’s sake.

https://www.fox4news.com/news/ohio-hunter-bags-monster-20-point-buck-had-eluded-him-years

I'm an audiophile on a budget. I can build speakers subs and treatment just fine but I have no plans on diy electronics.

Current setup. Gr reaserch nx studios diy kit, 4 dual 12 inch ripole subwoofers, Dedicated Room’ highly treated all DIY: 12"x 20", bass traps in 8 corners, 5 6"x3" diffusers, 4 4"x3" diffusers, 2 tube traps, 4 2"x4" absorbers, 2 6"x3" absorbers, 2 8"x3" clouds.

As far as electronics go,MAC(roon > HQP > BACCH4MAC ) > Supra USB > meitner ma3 > Mola Mola Kalugas.

I built the following circuit to flash some 25 watt incandescent colored bulbs on and off to the music.



I then remembered how some rinks in the 80's had lights that seemed to light to the music with some operating the opposite way and also being able to flash lights on and off as well.

Are there any light controllers that can put out a variable 0-5Vdc or do PWM using triacs on six individual channels with the ability to tell each channel what to do and also have an audio input that can control the lights?

If I found a LED controller I would build five more of those circuits minus R1 and adjusting the value of R2 to where full brightness occurs at 5Vdc.

I see mostly RGB controllers or traffic light controller kits, but those aren't right for what I need.

https://www.trioda.com/tools/triode.html is down ?
Alternatives ?

The reason I post it here because an old age stinginess prevents me from spending $20 on shipping from Turkey (but maybe I will have to skip that burger after all)

Hello again

I am planning on buying / building a streamer and dac. I want to be able to use a raspberry pi as roon endpoint, drive a screen or display and then also have the facility to input usb from my pc or laptop through the same devices. I am a bit overwhelmed by the choices we have in the Ian Canada product suite. Can someone give me some advice. I have written Ian as well. I would like to buy once but not all at once if I can avoid it. So getting the large capacitor equipped PSUs etc could maybe wait. I was looking at the project sections but got overloaded with the options. Any help or suggestions to get me started will be greatly appreciated. RCA outs to amp/powered speakers will be fine.

Thanks very much

Hi, my name is Vladimir. I moved to Spain from Belarus. I repair digital equipment.

Hello everyone, my name is Fausto and I am writing to you from Italy, I have been a HIFI enthusiast for 10 years. I listen to all good music, and I always like to experiment new things to try to increase the quality of my system.

I've built a lot of speakers. Ambient composer. Designed and manufactured ultrasonic detectors commercially.

Posting this here as not DIY related. Just a heads-up on what happened to one of my Wharfedale D-220 speaker drivers. I got a cheap class-D amp for the workbench to save some space 2 years ago, it only sees light usage and has been fine until I was awoken by a smoke alarm early this morning. No noticeable smoke or smell but the alarm would not reset, I turned the mains power off as a precaution and hit the sack. Fired up the bench this morning and noticed one speaker was down, opened it up and this was the result:


The driver magnet obviously got hot, melted the cage and sagged trapping the voice coil. checked the amp, full 18v of the PSU on one channel. The driver voice coil is slightly discoloured but not as much as I would have expected to reach that temp'.

Nothing obvious on the amp pcb, nothing bulging chipped or charred, it still worked fine when I clipped a 2200uF blocking cap on the output. Can't be bothered tracing the fault, The enclosure will be repurposed with my own TDA2009a amp circuit. Scratch one Wharfedale D1119 driver.

Regarding pros and cons of the options, and having a good collection of 12AX7/AU7s, I need to make a pest of myself (again) with some more questions for you preamp gurus out there.

First of all, does anyone around here think this dual plate follower design would produce enough second-order harmonics to be worth building? I like the idea of not having to screw around with cathode follower filament bias.

Will this thing have low enough impedance at both ends to drive a solid state amp from a computer's line level output? I lack fancy-pants math ability beyond beyond calculating resistor value for a desired voltage drop at x amps... and even then I just cheat with an online calculator.

Does anyone know of a safe vendor for the Chinese kit? They're all over eBay, but the sellers are all overseas and seem a little shady. There's nothing to be found on Amazon unless I'm looking in the wrong place. Otherwise I'll have to make it from scratch, which isn't too daunting except for rounding up the parts.

If I have to use a B+ voltage drop resistor, should it be calculated for the average plate current of both tubes, or the maximum?

Does the filament center tap really need to be 9 feet away from the ends as described? 🤣

Thanks for any and all opinions on this.

I’m a retired telecom engineer/instructor/manager with ROLM Corp, IBM, Siemens, Unify, ATOS. I repair/refurbish electronics (mostly audio) as a hobby. This hobby pretty much saved my life after suffering a stroke in 2013.
I’m in need of some help identifying some SMD capacitors. One of the DIYaudio members posted recently on the same Sony CD player/recorder. The online capacitor assistance is “not floating my boat”!
I’m looking forward to contributing in the future!
Cheers …. John in Dallas

I need a replacement meter for my later model Tek 570 curve tracer, S/N 5474.

There are several versions of this meter, including an earlier one that was also used in the Tek 130 L/C meter. Any help appreciated!

The following part numbers are applicable;
149-0010-00
149-0017-00
149-0022-00
149-0023-00

Thanks,
Art

Hi,

Ik recently purchased 4 Kenford HW-1206 woofers from the German webshop A&D Audio for 45 euro's each. Perfect service, quick delivery. When I received the drivers I found them labeled not Kenford but Rockwoord HW-1206. Ik had noticed speculation on the internet that these drivers are identical, and that seems to be the case.
The drivers are well made, heavy, and come with a rather big sized magnet. They feature large (rubber?) surrounds, capable of large excursions. There is however no specification of the max lineair excursion form the manufacturer. 5-6mm seems about right, as a guess.







Well ventilated:


First thing I did was running all drivers for about 24 hrs on 18Hz with about 4mm excursion. I tried larger excursions and did not notice umwanted mechanical noises. Then I measured the impedance and TS parameters. Driver 2 was clearly an outlier so I did a second run in with this driver for about an extra 18 hrs. That fixed the problem. Be aware that the image showing the 4 driver impedance graphs is with the first measurement of driver 2 (to be replaced later on).


White = driver 1
Red = driver 2
green = driver 3
yellow = driver 4

I repeated the impedance and TS measurements 17-11-2024.


driver 1 = Red
driver 2 = White
driver 3 = Green
driver 4 = Yellow

TS parameters (with the correct measurent of driver 2) measured with the Clio Pocket. The first column for a driver shows the first measurement, the columns indicated (2) show the second measurement performed after an additional 24hrs of burn in at about 5mm excursion, 18Hz. Essentially with Fs ~40Hz and Qts ~1,0 this is a good driver for a OB project.

(2) Second measurement

I have had the edge to get what I would call a good bench meter. I have plenty of digital handhelds, Fluke 289, Fluke 87V, Fluke 27FM, Agilent U1252A and then a Klein with an amp clamp of some kind that I generally use for auto stuff and where it will get dirty. I do have one bench meter, a really old Fluke 45. Not the highest resolution, but still dead on accurate. Kind of boring and it’s getting old, wait it is old.

I’m wondering if getting a bench meter is wise since I have so many other meters, but I guess I could sell some.

I really would like to get at least a 6-1/2 digit meter. I’d consider myself an extreme hobbyist. I love repairing and restoring old pieces and enjoy building diy amplifiers and preamps. I am guessing I really don’t need that resolution, but I would really like to have it.

The models I have been looking at are the Siglent SDM3065X ($745 USD), Keithley DMM6500 ($1600ish USD though it looks like directly from South Korea I could snag it for $1450), and lastly the Keysight 34465A. I also looked at a couple of used units, like on eBay there is a Tektronix DMM4050 that won’t boot for $385, but not sure I want to chance a repair on a unit that will have future screen issues.

So, the Siglent. It’s half the cost of the other two. That’s a pretty big savings. On the other hand it also looks like it’s lacking compared to the other two, there is a reason it’s so much cheaper. A huge plus for me is that I can purchase it on Amazon and pay interest free payments over the course of 5 months, $149 a month. That is incredibly helpful and may be the decision maker.

The Keithley DMM6500, personally I love this meter. I own a couple of Tek scopes so why not. I have done a ton of reading and it looks like the DMM6500 is fairly equal to the 34465A, but is less expensive and more people recommend. Plus I like the fact that the DMM6500 has a low ohm function, will be very useful for short finding on a circuit board. Honestly this is the one I truly desire.

The Keysight 34465A looks like a fantastic meter. It looks like it has a couple of shortcomings compared to the Keithley, but at the same time is better in a couple of ways. I highly sought I’ll be doing any data logging or anything like that. If I happen to find one that is used in good condition for a price that makes sense then I would pick up this unit over the Keithley.

I found one place at looks like I could pick up the Keithley and make payments through Klarna interest free over 4 payments, but it looks like the auto draw every two weeks, so $800 each month. If someone knows of a longer payment term please let me know. I could pay all at once, but spending that kind of money all at once, I’d get the side eye from my wife. Over several months, less of a big deal.

Anyways, looking for opinions on these units, maybe people that have used a couple of these have an opinion? What would you do in my situation? Financially it seem the Siglent would be the way to go, but it seems less “wow” and I’d hate to have buyers remorse wishing I had bought better.

Thank you,
Dan

DEVICE: Parasound HCA-2003 circa 1998 three-channel amp
SYMPTOM: 10+ seconds after power-up with no input signal being provided (i.e., @ idle), one channel's output voltage (as read by a DVM on the outputs) slowly starts to go unstable, varying somewhat sinusoidally several millivolts positive then negative, growing in magnitude to in excess of a couple of volts. (This, of course, can cause voicecoil over excursion/damage to a connected speaker.)
ROOT CAUSE TARGET CIRCUIT BOARD: With 100% certainty (after experiments swapping interconnects to/from other channel's boards and/or power supplies), I've isolated the culprit to be the Inputs Board. See pic. The right hand one-third of that board is the specific at fault circuit.
ROOT CAUSE TARGET CIRCUIT/COMPONENT: I simply don't know. I've A-B-C's each and every component across the three identical circuits (for the three channels) using only an ohmmeter and voltmeter. Have found all NPN transistors functioning OK, all PNP transistors functioning OK, all diodes functioning OK, all resistors very similar in resistance, pots all very similar in min and max resistance, all pot's resistance vary smoothly and similarly with rotation, all capacitors ohm'ing out very similarly.

QUESTION 1: What am I not doing that I need to do to isolate and verify what component(s) out of spec?

QUESTION 2: What additional diagnostic devices (scope, signal generator...) might be needed?

QUESTION 3: What type of component (i.e., cap, diode, transistor...) would you suspect in light of the symptoms?

There's some confusion about the G2 rating of this 6P15P. Some data indicates 330V for both anode and G2, while other comments suggests the G2 is "fragile" and should be de-rated, maybe down to 160V like the EL83.

So for those wanting to use this in triode e.g. in a PSE amp, how to proceed? A hefty resistor on G2 or what?

There's a thread on the 6P18P which contains some information but nothing conclusive. Francois G was going to test it but no further info. Maybe he can update?

https://www.diyaudio.com/community/threads/russian-6pi18pi-6-18-any-use.391138/#post-7146682

Dear diyaudio community.

I need your help with my RAKK DAC MK IV board, (version 2.1.) I use for my DIY DAC.

I would like to use the I2S input for the first time.

My plan is to use the I2S over HDMI board from Ian Canada as input.

This offers MLK, SCK (BCK), LRCK and SD (Data) as outputs.

Unfortunately, I do not have any information on the assignment of the 10-pin connection block on the RAKK DAC MK IV board.

Does anyone know the pin assignment of the connection block?

I would be very grateful for any help.

Unfortunately, I cannot reach the developer of the RAKK DAC, David Davenport, by email.
He seems to be retired and I only have his work email address (from Raleigh Audio), which is apparently no longer active.


Cheers, Niels

Ok so i always see the bracing that goes from a panel to a front panel like inside a horn

does that needs to be like that ?




can you just brace like i saw on some 2000 era Yorkville's
LS608's to be exact

they use like a 1" by 2" wood sticks in the corners
like the below

does that augment the corner structural integrity if you drop it
or the roadies abuse the boxes ( like always )




and what about mid panel bracing like this that i found inside the yorkvilles
in L shape



can we get away with no L bracing like the below




and my question is.... do you really need to do the bracing like the below ?
or with the L braces along wide areas in the panel when flex occur you can be ok








also can you make it with single baffle wall or use double baffle wall

Hi. Does anyone recognise the capacitor in the picture, marking S7Jr .. isn't that a Polymer Tantalum cap ?



Oneminde

Hello community,

i am a new member of diyaudio.
My goal is to build a diy pc audiosetup starting from scratch, with the pcb and the speakers.
I am not new to electronics, i made 2/3 years in school and work in an environment where electrical knowledge is required, but am a complete noob regarding audio stuff.
So i signed up, hoping to learn some new stuff and getting help for my little project.

Hello all, I am in Scotland and have had the same amp audio lab 8000a and mission 763 speakers since I could afford a hifi system and have been very happy with it until now

Hi all.

Please bear with me, this is the second account I have created as my main account was flagged as a spam bot.
I sent an email to request it to be re enabled 16 days ago, as I believe this was an error, but had no response as of yet.

I apologise for breaking any forum rules to create this second account, but I would appreciate being allowed back onto the site with my main account, or at least be able to discuss why my account was banned for asking a question about designing a speaker enclosure for a open source project I'm working on.

Kind regards
Ben Jackson

I bought a used Anthem PVA-7 amplifier, knowing it was not working on 6 of the 7 channels. I have reversed engineered the working channel (no schematic) and have all 7-channels working. As I was cleaning it up, I got to looking at the fuses (only 4 rail fuses the other 4 were missing) and I have some reservations to their rating.

The main fuse coming in was a 15A fast-blow ceramic, but the board clearly states 15A slow-blow on the PCB - so I have changed to a 15A slow-blow ceramic fuse.

The power rails, +/-55Vdc, has a pair of fuses for each Heatsink (three heatsinks have 2 channels and the Center is a single channel on a heatsink). In the amplifier the Center (single channel h/s) and one of the Dual channel h/s boards came with 15A fast-blow ceramic fuses. I question the amperage and being fast-blow type, not to mention they look brand new (red flag). While I was repairing and testing to make sure I fixed everything, I used 6.3A slow-blow fuses. No trouble but I have only repaired and tested/listened at low volumes up to this point and I don't want to blow single/both fuse(s) when I give it a real test.

Any one know the specific amperage/style rail fuses that should be installed? Are the 15A fast-blow ones correct? The amp has speaker, over current and voltage protection so the fuses seem to be there in case of catastrophic failure in one or both of the rails.

The amp is a 2-pair (2SA1302/2SC3281) TO-264 output per channel and I currently have it biased at ~25mA per channel and the h/s is slightly above room temp. after 2 hours of low volume music (~5 watts), with no more than 10mV of DC offset, running at +/-55V rails, with a 40-0-40 Vac rated at 8.8A transformer.

These coffins sound very good indeed but boy they do look **** !

Can I call them Rogers Pro 9TL’s ?

Hey, I'm Ismael and I like headphones and audio and building stuff and learning more stuff and want to share my experience with and learn from more experienced members!

I’ve got a 2 watt DIY SET amp built on the Decware zKit Schematic (including the anniversary modifications/bypass capacitors)
https://www.decware.com/newsite/ZKIT1.pdf

I’ve been using this amp for about three years and when I shut it off if the source is still playing the music fades out over the course of 10 seconds or so and starts to break up before going silent. The last couple of weeks I have noticed that it started cutting out instantly when switched off. Yesterday I switched it off and it cut out instantly; I changed interconnects and turned it back on. The tubes lit up and everything looked normal but it wouldn’t produce any sound. I let it sit about 10 minutes and tried again. Still no sound. I powered it on today, about 16 hours later, and it is working normally again. Anyone have any ideas on a diagnosis for these symptoms?

Hi First time here I am looking for .laser player VAU1254/01 mine doesn’t work anymore ,does anyone wherry I Can Bey it. Gr Frans