I've been looking for a big speaker project, and like Troels' The Loudspeaker, especially after some fun with 15" JBLs and EVs with CD & waveguides a few years ago.

Now the problem is plans and crossovers shipped to Australia is close enough to $2k before drivers. Yikes.

What are some options? Any other recommended designs out there?

Dayton drivers are reasonable easy to access here...

Just for educational purposes (and because of the excellent results of this one) a picture of a custom built Noratel Imed medical isolation transformer.

This one has something non standard. It comes with 2 primary 115V windings (for 230V in series) and 3 separate secondary windings 2 x 115V/230V so 3 galvanic separated groups. The device of course has electronic slow start as it is 1000VA (no power saving techniques found for the bypass relay). It also has a PE leakage test circuit with test and reset button. So in effect this device functions more or less like 3 transformers in 1 casing. Also nice is the built in mains filter which is lacking in other models of this brand.

Everything is double pole so 2 mains fuses and a double pole mains switch. It was meant to be used with endoscopes.

The rule of thumb with audiophiles seems to be the higher the voltages the smaller the chance of finding PE in the installations and/or DIY devices. Please see the meticulous wiring of PE.

Hitachi HMA-8500 MKII FET Recap advice

I'm starting restoration project of lovely sounding Hitachi HMA-8500 MKII FET power amp. Think it'f from circa 1984

Plan is to replace speaker relays, speaker terminals an least all electrolytic caps. There has been couple things that i'm not sure and would greatly appreciate advice. Attached is schema and component list

1. Main DC caps are 8pcs 6800uF 63V 30x80mm. Is it safe to use little bigger ones, like 10 000uF?
2. What are the caps on signal path that should need special attention. For example to use something like Wima MKS to replace elko's?
3. There is types of capasitor on part list like Ceramic discal, Film fe, Mylar film. How does these things age, should i replace?
4. What about other components that needs attention?

Kalle

2 channels AlephJ with 2SJ109 and closely matched IRFP240's
For sale with or without heatsink.
They have been playing for ~10 hours but going to test the AlephJ=x

Make me an offer!

Here is a Canadian version of Wordle

Canuckle 46 4/6

⬛⬛🟥⬛⬛
🟨⬛🟥⬛⬛
⬛🟥🟥🟥🟥
🟥🟥🟥🟥🟥

what is an equivalent of transistor ks 2200?

Hello!
I'm working on a SE amplifier that has D3a for the driver.

Here is the diagram for the supply.

6AU4 -> LC Choke -> 100uf -> 16H 12R -> 100uf -> 180v @20mA for D3a

Which value should I use for the LC Choke from either ISO (Tango) or Hashimito?

http://www.acoustic-dimension.com/iso-transformers/iso-transformers-choke-page.htm

http://www.acoustic-dimension.com/hashimoto/hashimoto-chokes-transformers.htm

Thanks in advance!!

Using a TPA3116D2 amp, (50watt L/R, 100watt sub), what should I expect if I pair it with a 10" 600watt subwoofer?


...my frame of reference being 6"/25watt powered subwoofer

Hi there,
I gave the Sousaphone 20 a bass, TIW 250 XS with 2 Dayton PR DSA 215 each, complement each other perfectly, you wish for a 40 sqm room and 6 m listening distance, when I remember the huge Lowther experiments in the 80+90s, the sousaphone with bass is the smallest and "best" solution. The Lii Silver8" makes a slightly better impression in the sousaphone than the DX2, also because the Lii's magnet is much larger and thus reduces the pressure chamber volume, which could be achieved with a PM2A and, with a hole in the back, with the PM4A.
Cork outfit is still missing.

After 200 hours listening, I am confident to offer the Audio Note upgrade option:​

46 x Audio Note Tantalum Resistors $5.25 each
4 x Takman 2% (3.3ohm and 8.2 ohm)
2 x AMTRANS 1% AMRG (15 ohm 2W) $9.50 each
2 x Audio Note Silver 0.1 600V $355 each
2 x Acrylic Bracket (to secure the silver caps) Free with Silver Cap

a big satellit FL BL, thanks to IVO once we talked about cork, now i did it, a asymetric cork front horn ~1,3 kg http://www.hm-moreart.de/150.htm

I'm thinking about getting a subwoofer to go with some AudioEngine A5s. I don't need anything extravagant, just something adequate. Suggestions? I guess having a good low range is more important than having a lot of power.

Hi,

Sorry if this is a very basic question. Still wrapping my head around the physics of horn design. Reading through the MJK notes, he mentions the coupling chamber, which if i'm guessing right is another name for a compression chamber?

In the notes he talks about the 'coupling chamber area at the closed end' & 'coupling chamber area at the open end'. what exactly is this referring to? The pictures given show that the coupling chamber is rectangular (I don't know if that's always the case). So is the closed end the short side, and the open end the long side?

Thanks

So i went building this 730 Liter bad boy with 2x 15xl1400 on 4ohms from faital pro. I just now realized that at the throat beginning i literally have no throat area for one of those two speakers... Once i started thiniking about it got a bad feeling about it...

This enclosre got for the 2nd speaker theoretically compressionratio of 3,3, when considering both speakers would have the same area at s2. But what about the first speaker? It has that tilted plate facing the speaker which narrows its throat area quite a lot... Do i have to reconsider the compression ratio for it?

Furthermore since its facing plate is tilt, wouldnt that apply assymetric forces on the cone? This enclosure is very large, so i already expect to hit xmax very fast. Combining xmax and asymetric loading on the cone would lead to coil rubbing, wouldn't it?

I already got my thoughts about shifiting the speakers a bit higher and reducing the length of the tilted plate to reduce assymetric loading of the first speaker. Do you think that it matters in the first place?

Hi all,

Could anyone tell me please if the following (that I've come up with) is sensible, especially with respect to how many voltage regulators I am using and noise filtering in a mixed analog digital design?

(pictures attached)

I'm looking to make a pre-amp with input / output selector, so looking to use a microcontroller (PIC or AVR family, most likely try a PIC) so need a stable +5V DC supply, plus a PGA2311 Stereo Audio Volume Control chip thus requiring +-5V analog for the internal Op-amps, plus I'll be using a few HFD4/5 subminiture relays (+5V switching voltage).

I'm not sure if I need the LC filters at all. Would the LM7805/7905 regulators remove much of the digital switching noise from the microcontrollers?

Thanks! 🙂

I am building a pair of Jeff Bagby's "Kairos Woofer Modules" for use with my Jeff Bagby "Aurcicle", RAAL/SB Acoustics standmount speakers.

These woofer modules are not subwoofers, but designed to create a 3 ways system when used with a standmount/monitor speaker.

The design, for the low pass portion of the crossover (2nd order Lenkwitz-Riley) includes a 5.0 Mh inductor in series with the woofer, and a 200 mF cap and a 3 ohm resistor in parallel. The inductor is an laminate core with a DCR of .25. The SB Acoustics woofer is 6 ohms.

My question is, what would the overall effect be, if I replaced that 5.0 mH inductor with an air core with a DCR of 1.2? I guess it would attenuate the bass output, but by how much? And would it do it over the entire range of the woofer's output?

Thanks!

Kairos Woofer Write up

Very lightly used

These sell for around $100/ea, asking $100 shipped for both OBO

https://www.bbc.co.uk/news/technology-60927032

Putting a fan inside a headphone does on the face of it seem like the daftest idea I have heared in a long time. Even if the noise cancelling gets rid of the whine for the user surely everyone around will hear it? then again Dyson's main product is a fan and they just scale and repackage as a vaccuum, a hairdyer etc.

I don't think I am the target market for this 🙂

HI EVERYONE,

I SEARCHING FOR A REPLCEMENT SOEKRIS DAM 1021

MINE WAS DAMAGED BY ESD AND I WAS ADVISED BY SOEKRIS THAT ITS NOT REPAIRABLE 🙁

SO IM AFTER A REPLACEMENT UNIT

MUCH THX 🙂

JBL L36 speaker pair

Original, unrestored.
Oak cabinets.
Drivers in great condition, the bass driver was refoamed a few years ago.
Grills (not pictured) in good condition

Could be a good restoration project or upgrade such as: http://www.troelsgravesen.dk/JBL-L26-3way.htm
$500 OBO -- local pickup in the greater Seattle area

More pictures available on request

I’m thinking about building one of the usual suspects on the Pass Lab forum. Specifically, I’m interested the Iron Pre, BA-3 pre, and Wayne's BA 2018, but any other suggestions are welcome.

I’m currently using a Vacuum Tube Audio SP14 tube pre in front of my SissySIT, and have used it with my M2C and M2x. It works very well with all of them, but want to try something else. Once I complete my F2J build my intention is to start on one of those preamps.

I have found that I like a preamp with gain. Buffer or passive preamp I feel they sound a little flat.

Any insight is greatly appreciated, because there are no bad ones.

Hello all, I recently purchased a set of Fostex FE168NS, I own different Mark audio's and wanted to try the competition...they have been playing on the shelf for 200h at low volumes for breaking in, but now it's time to fit them inside a cabinet...I have built all frugal horn sizes with different speakers used, some where amazing, some not that great imo...I also have a set of Joan playing now with Mark Audio CHN120 ( playing great, the highs are really crisp but not fatiguing at all, bottom is still to be fine tuned but allready great) but my all time favourite is still and by far the fhxl with MAOP 10.2, this one kicks any speaker I have owned out of the game (many and some really expensive ones like wilson audio, bw 801d, etc...) . I also built the adjustable duct type with maop 10.2 with mitigated results ( https://sites.google.com/site/speak...iver/-diy-adjustable-duct-type-sddbh-sddbh-ad ), bass extenssion is better compare to FHXL, but that's all, no live feelings, no details in mids, no wide open scene, etc etc, whatever the settings I tried... anyway it was worth a try and they play great in the garage... last but not least, I am also building a set of Fonkens with A11MS and will add a set of Fonkens with MAOP's that I will recover from the adjustable ducts and replace with A10.3 or pluvias (no need of MAOPs if there is no detail and just to play loud IMO...)
Now comes the questions...
By listening to the fostex open air next to MAOPs or 11MS or ch120 , they are much much crisper and agressive in the upper range, and this scares me a bit...
I am not sure about what cabinet to use, I planned to use the adjustable ducts when purchased, but with the mitigated results I had with MAOP's I won't be using this design...
I would like to use floor standing speakers, not 2m high, and maybe a front mouth this time...
Are there any floor standing Fonken designs for this speaker, can I use designs made for other Fostex like FE168∑, in case of Frugel-Horns, should I use the XL or the Joan???,
Does anyone have some great experience with them?
And if I would like to calm them, does anyone EnAbled them allready, are there any other mods I could do, I just don't want any bsc filters...

Thank's,
Yves

I hadn't seen this choke discussed at all for audio, but the specs on paper make it look like an interesting anode load.

Hammond's page here

Says 2k DCR.

So I have a pair of Sony SS U501’s. The woofers need replacing, but the basket does not fit. I guess now that I think about it I should have bought spacers, but I went and cut the box, now the hole is too big! I know that I can use plywood and fix this, but is there a product out there to help dummies like me? They are 12” woofers.

Hi,



I wrote a Python package to control ADAU1701 / ADAU1401 from PC.



https://github.com/Wei1234c/SigmaDSP



FYI



Wei Lin

Can anyone help I'm looking for one IXCP10M45S Switchable Current Regulator

Thank you

Given a two-way crossover network where the low-pass filter for the woofer is 1st order, and the high-pass filter for the tweeter is second order, what should the crossover frequency be? Would it be the frequency at which the total attenuation of roll-off of the woofer itself plus that effected by the low-pass filter equals -6 dB? Or should the two cut-off frequencies be unequal according to some design method?

I have quite a few books that discuss crossover networks, and I've checked the ESP site, but there is no treatment of mixed order crossovers there. Possibly the only way to optimize a mixed order network would be by testing it?

As I'm analyzing a commercial loudspeaker system and I don't have the full specifications of the drivers of it, I'm unable to simulate the design to see if it has the correct cross-over frequency.

Regards,
Pete

Hi there guys,

Does anybody know the value of R417 and R412?
Does someone has the schematics of this amp?
Also, what output fets are suitable for this amp?

Hi all I am starting GB for a Simple Discrete Current-Mirror IV Converter, à la AD844 from XEN audio
LINK to thread for technical discussion.
PDF with description attached.
View attachment CM IV Description Public 200913.pdf

We need at least 10 sets.
1 set includes 5 PCBs, left / right versions, of which 2 pairs will be supplied. There is an additional "neutral" version which is meant for test build.
and also there will be BOM supplied with PCBs.

Prices:
- 1 set of PCBs will stay at 20€
- 2 channels single (6 matched pairs) + test (not matched) 20€
- 1 PCB set (12 matched pairs) + test (not matched) 25€
- shipping EU - 10€, World - 14€


SPREADSHEET for GB

Hi all. I'm planning on replacing the KEF woofers' donuts which have shown signs of cracking because of age. There are many ways to get the necessary repair kits online, including eBay, of course. However, I have no idea which is the best for the KEF - I've noticed that some of these donuts have been reported as stiffer than others, and I believe this will affect the woofers' performance. Would appreciate advices. Thanks.

Has/is anyone using panasonic polypropylene radial capacitors in a crossover?

Hi, I have a Burmester 051 in need of repair. Burmester does not have any contact details - all enquiries have to go through the dealer and my local dealer have not been helpful.

I have two burnt compontents (one is a resistor, one is a resistor or capacitor) just next to the power inlet. See attached picture.

Please, can someone pop the lid of theirs and send me a picture of these components so that I can find suitable replacements? There's probably no need to measure anything - a good picture will probably solve my problem.

Best Regards
Audun Melbye

I bought second hand this amplifier. The only issue was playback from pc through usb port. The amp was seen by pc as mass storage device.
I found out that previous owner flashed wrong firmware to this DAC. I found flash tool from c-media and their firmware 2203. The input is working now, but I would like to bring it to original state.
Onkyo official doesn't want to share their on board firmware, so I'am asking you guys for help.

Hi,

I'm looking at my next valve amp. build using an existing chassis and see that a certain Power Transformer supplier is offering a number of options for the same footprint/cutouts. The options include 3 variations in height, as designated in the title. Only a single spec. is listed:

Input voltage: 0-220V-230V (default) Output voltage: each winding voltage can be made according to customer requirements a), 380V-330V-0-330V-380V DC=0.2A, b), 5V/3A (rectifier filament winding), c), 0V-2.5V-6.3V/3A d), 6.3V/3A

The price varies quite a bit and the supplier is stating (incorrectly?) the current ratings are the same in each case. I would think that more iron would indicate higher power rating? Or am I missing something here?

Thanks in advance!

Hello, every one, I would like to introduce our new product "VT DSO-2810F" here. Together with the Multi-Instrument software, it turns your PC into a 2x100MHz Oscilloscope, Spectrum Analyzer, Multimeter, Signal Generator. (Note: The Signal Generator function is available via sound card or other DAC device, rather than the VT DSO-2810F unit). The unit is small, portable and has a metal enclosure. The price is US$250 (FREE shipping worldwide).

The Multi-Instrument software can be downloaded and tried for 21 days with full functionality using your computer's sound card for ADC and DAC at:

www.virtins.com/MIsetup.exe
or
www.multi-instrument.com/MIsetup.exe


Turn a PC into multiple virtual instruments!


1. Package Contents

1) VT DSO-2810F unit with a hardware bundled Multi-Instrument Standard software license
2) 2x100MHz Oscilloscope Probe P2100 with two switchable positions: x1, x10
3) USB cable (1.5 m)
4) CD (contains the copy-protected Multi-Instrument software and VT DSO-2810F driver)


2. VT DSO-2810F Hardware Specifications

1) Sampling Frequency: 100MHz, 50MHz, 20MHz, 10MHz, 5MHz, 2MHz, 1MHz, 500kHz, 200kHz, 100kHz, 50kHz, 20kHz
2) Analog Bandwidth: 40MHz
3) Number of Input Channels: 2
4) ADC Bit Resolution: 8 Bit
5) Input Voltage Range: (+-)1.2V*, (+-)12V*, (+-)24V* (one selector for two channels)
6) Maximum Allowed Input Voltage:
(+-)1.2V*: <= (+-)10V
(+-)12V*: <= (+-)24V
(+-)24V*: <=(+-)24V
7) Coupling Type: AC/DC (one selector for two channels)
8) Input Isolation: No
9) Terminal Type: Referenced Single-Ended
10) Buffer Size: 2000 bytes per Channel
11) Scan Time: 20us~100ms (with buffer fully filled)
12) Trigger Source: CH1 only
13) Trigger Level: Around 0V
14) Trigger Edge: Rising, Falling
15) Trigger Mode: Auto (Free Run), Normal
16) Input Impedance: 1 Mohms , 13 pF
17) Rising Time: <10ns
18) Streaming Supported: No
19) Interface: USB
20) Casing: Metal
21) Device Category in Multi-Instrument: VT DSO F1
22) Power: Bus powered by USB port, no external power source required.
23) Power Consumption: Max. 1.5W
24) Dimensions: 132 mm (L) x 63 mm (W) x 24 mm (H)
25) System Requirement: Windows 98 or above
*Under these input voltage range selections, the actual measurement range is: -1.05V~1.12V, -10.5V~11.2V, -21V~22.4V respectively.


3. Introduction of Multi-Instrument 3.1 (Standard)

Multi-Instrument 3.1 (Standard) is a powerful PC based multi-function virtual instrument software. It supports a variety of hardware ranging from sound cards which are available in almost all computers to proprietary ADC and DAC hardware such as VT DSO-2810F, NI DAQmx cards and so on. It consists of a dual trace oscilloscope, a real time spectrum analyzer, a signal generator and a multimeter, and can run them simultaneously.

For a sound card based system, software triggering is supported. It features a specially designed data acquisition approach, which is able to monitor the input signal continuously without missing any trigger event before a frame of data is collected. It has a very fast screen refresh rate (typically greater than 50 frames per second). It supports sophisticated triggering method including pre-trigger and post-trigger. Both level trigger and differential trigger are supported. For a non sound card based system, the triggering capability depends on the hardware used. Hardware triggering is supported if the hardware used supports it. Software triggering is supported if the hardware used supports data streaming.

The software has a multilingual user interface, including English, French, German, Italian, Spanish, Portuguese, Russian, Simplified Chinese, Traditional Chinese, Japanese, and Korean. It has been widely used in education, scientific research, audio engineering, electronic engineering, medical diagnosis, vibration analysis, etc.


4. Functions of Multi-Instrument 3.1 (Standard)


A comprehensive range of functions are provided in Multi-Instrument (Standard), including:

(1) Oscilloscope
Oscilloscope Mode: dual-trace waveform, waveform addition, subtraction and multiplication, Lissajous Pattern, transient signal recording, voltmeter.

Record Mode: Record data to the hard disk continously until the recording process is stopped manually or 2 gigabytes of data has been recorded, whichever is earlier. During the recording process, acquired data will still be analyzed and displayed to keep the screen updated in real time.

Roll Mode: Data displayed in the Oscilloscope will shift left gradually while the newly acquired data are added from the right.

(2) Spectrum Analyzer
RMS amplitude spectrum, relative amplitude spectrum, octave analysis (1/1,1/3,1/6,1/12,1/24, 1/48, 1/96), frequency compensation, frequency weighting (A,B,C,ITU-R 468), moving average smoothing, peak hold, linear average, exponential average, measurement of THD, THD+N, SNR, SINAD, Noise Level, IMD, Bandwidth, Crosstalk, Harmonics, Peaks, and Energy in user defined frequency bands, phase spectrum, auto correlation function, cross correlation function.

(3) Signal Generator
Function generation, multitone generation, arbitrary waveform generation, burst tone generation, MLS generation, DTMF generation, musical scale generation, white noise and pink noise generation, and frequency/amplitude sweep signal generation. Fade In / Fade Out of the output signal.

(4) Multimeter
RMS, dBV, dBu, dBSPL, dB(A), dB(B), dB(C), Frequency Counter, RPM, Counter, Duty Cycle, Frequency/Voltage Converstion, Cycle RMS, Cycle Mean. The latter seven modes involves a pulse counting process, with the counter trigger level, hysteresis, frequency dividing ratio adjustable.


5. Extended use of the Multi-Instrument Software

With the VT DSO-2810F unit connected to the computer, the Multi-Instrument software will run under the licensed mode. In Multi-Instrument, the ADC device and DAC device can be independently selected. For example, you can use the VT DSO-2810F as the ADC device and your computer's sound card as the DAC device, and they can work simultaneously. Or, you can use the sound card for both ADC and DAC. Note: the test lead (or probe) for sound card is not included in this pacakge, but you can make the connection by yourself or purchase it from us separately.


6. Software License Information

Multi-Instrument has six levels: Sound Card Oscilloscope, Sound Card Spectrum Analyzer, Sound Card Signal Generator, Multi-Instrument Lite, Multi-Instrument Standard, Multi-Instrument Pro.

Multi-Instrument has five add-on modules/functions are: Spectrum 3D Plot, Data Logger, LCR Meter), Device Test Plan, Vibrometer.

The standard package of VT DSO-2810F contains one hardware bundled license of Multi-Instrument (Standard) without any add-on modules/functions. "Hardware bundled" means that the VT DSO-2810F hardware unit must be connected to the computer in order for the software to work under the licensed mode. Otherwise the software will work in 21-day fully functional trial mode. No softkey (activation code) and hardkey (dongle) will be given under the hardware bundled license.


7. Software Upgrade policy

Software upgrade in the same level is always FREE. When a new version is available, you can just uninstall your current version, download and re-install the new version, as long as the VT DSO-2810F unit is still supported by the new version.

Software upgrade to a higher level can be purchased from our webiste. The license bundled within the VT DSO-2810F hardware unit is remotely upgradable.


8. Refund Policy

One year warranty against defective materials and manufacutring defects for all hardware parts inside the package.

Return for malfuntional item is accepted for refund within 7 days after you receive the item. For full refund, the package must be in the same condition as received with all accessories. The delivery of the returned item must be prepaid by the customer. You must contact us first before you return it.


9. Screenshote examples

I'm starting my journey on the new (to me) cs3318 8-channel analog volume control chip.

for the last 2 years or so, I have been using singles and pairs of pga23xx chips and now I'm going to give the cirrus 8ch chip a try.

today, I soldered that expensive chip onto a schmartboard:



and since this chip is 3.3v based and my arduino is native-5v based, I'll need i2c level conversion:



I'm using my Volu-Master code base (newer version of what is on AMB.org's website for the LCDuino and alpha10 preamp). since the cirrus chip works very similarly to the pga, it should be a few lines of code change to at least be able to control the master1 fader group (in theory..)

will continue as progress is made...

Hi all
Just picked up a Reisong A10 stereo from amazon. Just getting it going and was having an issue,not sure if its me,the speakers,the A10 or all of the above. It sounds flat to me on the vocals, just sound like it needs more treble or something. I am using it with Polk floor speakers with 90db sensitivity.

I ordered some klipsch bookshelf speakers that will be here tomorrow just to rule out a speaker issue.

The music sounds good, its just like the vocals arent there,fuzzy or flat sounding and just not clear.

I didnt have it heated up for 30 mins before use,but i did use it for 20 mins and it didnt seem to stop. I played several vinyl LPs I listened to with the cheap 80 dollar tube amp i got from amazon a few months ago which has bass and treble adjustments and it sounds so much better on the cheap one even with the polk floor speakers.

Any ideas or opinions?

I have a pair of what I believe to be Acoustat 1+1 with mk-131-b interface. I have had these for decades and they have been in storage for 10 years. They have a very low output. How do I go about rebuilding them? The boxes are riveted so I haven't even been inside them for an inspection. Which rivets do I drill to at least open the case? Am I about to get in over my head? I have repair experience, just not on this type of speaker. Am I wasting my time?

Thx,
Don

I am a digital fabrication enthusiast looking to dip my toe into the world of DIY audio. I know basically nothing about speakers, but I'm keen to learn more. My primary knowledge area is CNC machining, 3D printing and laser engraving which I hope to put to good use in creating custom enclosures. I'm currently without a workshop, but I will be moving into a new house later this year where I will be able to start building again. If you are in my neck of the woods, feel free to say hi. I would be very keen to find a convenient way to bring speaker components into the country as shipping has been brutal lately.

Has anyone used a Vidar in BTL mode (400W at 8 ohms) ?

Documentation limits its use to speakers only 8 ohms (and above I guess).
However, since the impedance of even an 8 ohm speaker can WILDLY vary and go even down to 2 or 1 ohms in extreme cases, does this cause any damage to the amp if used continuously ? The amp is supposed to have thermal shutdown so I presume it would not be damaged but has anyone ACTUALLY used it extensively in this mode ?

The idea is for about $1500 (two Vidars), one can get a 2 x 400 W amplifier. It is an incredibly sweet deal.

Came across the TAS6584 today, looks extremely interesting. Here are the major highlights from the datasheet:



These chips are currently listed as "preproduction" and do not seem to be available just yet.
Biggest news since TPA3255 IMO, Digital input, built-in DSP, 4 channel, what's not to like?
Looking forward to this!

https://www.ti.com/product/TAS6584-Q1

🙂 The static voltage of this rtvc amplifier is 280mv. I'd like to know how much its static current should be adjusted for the best state. I hope to have a pleasant audition effect,，thank you,

This seems a rather DIY friendly option for cloning. Anybody thought about this ?

Positive reviews in Stereophile:

"The Sun is the finest stand-mounted speaker I've heard: a modern classic."
Read more at http://www.stereophile.com/content/trenner-friedl-sun-loudspeaker#ecJI1J1x2RRRSKwF.97

The driver is a single 5" coaxial unit: Seas Prestige L12RE/XFC (H1602) 5" Alum/Fabric Coaxial

And it is readily available, for example, from Madisound. Yes. it's a pricey driver but if it sounds good...

Hi,

I have a Minidsp DDRC-24 for sale. I'm looking to get $350 OBO for it.

1. I've verified with Minidsp that the license can be transferred to the new owner with no cost. I just need to email them your user ID on the Minidsp site.

2. Sale includes the unit, power adapter, and a USB cable. I don't believe I still have the original box but I will check before I ship JIC I do.

3. Unit is currently flashed with latest DDRC-24 firmware. Note that you can also flash the 2x4HD firmware onto it if you don't need Dirac. IIRC this gains you additional FIR capabilities and a 96khz internal sample rate.

4. Drivers/firmware are available on the Minidsp site once you are a registered owner of the device. Dirac can be freely downloaded from Dirac's website.

5. US shipping, PayPal payments only.

Thanks for looking.

The noise sounds almost like a geiger, a rapid clicking noise that's nearly a buzz. Quiet, but loud enough to be heard outside the monitor. Various Internet forums suggested replacing capacitors, such as the 2200pF input safety cap. Other posts say these fixes failed after a month or more. I tried swapping that capacitor, with no change in behavior. It also strikes me that capacitors don't make noise, so the real culprit must be something else, right?

In the attached file I've circled the area where I hear the clicking coming from. The two aluminum heatsinks hold transistors, and the black square in the center is a transformer. I think the large black circular-ish thing is a coil of some nature.

I'm posting only because the number of things that could make noise in a circuit like this are finite. If it is a transformer, can I just like, cover it in silicone and call it a day?

Worst case scenario, I'll buy a replacement board on eBay

I bought a new Hurst motor for my AR XA turntable and started to replace it, but have a question.

If C-2 is added between the yellow and black wires per the attached drawing, won't there be power on the motor at all times, even when the switch is "off"?

Hello! First, let me state that I am not a hardcore DIY'er. I am interested in good home audio, and have been researching Class D amps, both DIY and the retail (especially Behringer). It seems to me that for higher powered units, it has become very hard to beat retail Class D such as the Behringer "iNuke" line. This assumes of course, that the specs are honest 😎 I am old (50) school and use the "RMS watts" if shown, not the bridged-mono-peak ratings trumpeted by the coked marketing department

I am intrigued enough that I bought a NU3000 that should be more than enough to power 4 Bose 901 II in a large room. Also it will be interesting to see how it compares to the Sunfire "300x2" it may replace.

I know that much of DIY is the joy of building something yourself. But, can anyone beat or even match the retail amps (such as Behringer) nowadays. Perhaps you DIY'er should be buying new and cannibilizing for parts? For example, by specs and my admittedly limited knowledge, I would guess the NU6000 is basically two bridged NU3000 (internally) for only $100 more in price.

My system now is blumensteinaudio orcas and an svs sub. The orcas go down to a few hundred Hz I'm guessing.

I'd like to add a pair of woofers in separate enclosures to handle the low end, and maybe get rid of the svs sub. It's a small space and I don't play loud. I'd be using the Pass active crossover network from the diyaudiostore.

I can't seem to find any. There are small (8") subwoofers like this, but I'd like to hear from you about that. Blumenstein sells,some, but they are very expensive and use a cheap dayton ($30) driver.

Power would come from either: threshold s/200 (100w per side), bridged monoblocks apt holman (200w per side), or subwoofer amps (bash 300s)

Doesn't really include anything but the base and the scope.
I might be able to ship just the scope, but it won't be worth the cost I think.
$99 OBO local pick-up

I use a miniDSP 2x4 since some years back. Wanted to improve my cabling, until now I have had some really inexpensive cables with bad fitting RCA-connectors.

Bought some double screened (copper braid and foil) low capacitive coaxial cable, Canford SDV-M. Had some goldplated RCA-connectors from Switchcraft that I soldered on.

I was most surprised to hear a crackling noise from my speakers. Did not matter if I had the new cables on the in- or outputs, same crackling. Tried another cable that I had around, RG62 with some nice plugs. Same noise. Switching back to the crap cable and it was all gone. Having the crap cables attached only at the power amps results in hum. The better cables attached that way are silent. Removing the miniDSP from the setup and having the new cables directly from the preamp to the power amps works very well.

Why do I get this crackling noise with the "better" cables together with the miniDSP 2x4?

Hi! I recently won a biding for alot off recycled chips. These will be listend on ebay soon but if anyone are intrested give me a bid and how many you are intrested in buying. More = cheaper/pcs

Toshiba TA8605N
Toshiba TA8644N
Toshiba TA8606N
Toshiba TA8701N
Toshiba TA8718N

Sanyo 7297
Sanyo LA7397

LGS7445

I will add more variants soon when im done looking through all of them😀

I have been building a MooseFET preamp for over a year. Before running things need to be set up.

I am confused about using a voltmeter. The manual states "Upon powering the unit, adjust P1 for 24.00V on the B+ rail (the power side leads of R104 or R204 make a good test point for this)."
Where do I put the negative for the voltmeter?

Also same here "Once the B+ is confirmed, with an accurate voltmeter, check the drain voltage (the drain side leads of R104 or R204 make a good test point for this. See image below). While checking the drain voltage on Q101"

I have tried it in my system and something is wrong. Sound is only just audible at full volume with no lower frequencies. Also a loud buzzing that isn't affected by volume.

Hello,
I'm trying to find out where the ES9023-DAC board's analog output is wired onto the A2 main board. I ordered the DAC board separately and want to install it in my factory built Beyer A2 Pro clone. (No instructions were provided, of course!) If anyone has experience building this unit as a kit with the DAC, please let me know!
Thanks,
William Greywolf

Hey,

Helping a friend out with a Carver TFM24 power amp.

He recently bought this off CAM, and it had been running perfectly for a couple of week, and then all of a sudden started distorting. I opened it up when visiting him, and couldn’t see anything obvious, so closed it back up and took it with me.

At low volume, sounds as I suspect it should. Nothing is exaggerated, there is no noise, hiss or hum coming from it. But as soon as volume is turned up only a little bit, it starts to distort. Sounds to me like the gain is out of control on it! Sounds like it’s being seriously over driven.

He had the issue with his preamp, and I’m repeating it with mine. Mine works perfectly with other power amps I have on hand.

Anyone have any thoughts where I should start the journey? I’m hopIng it’s not toooooo complicated that I can perhaps help save him the cost and time of sending it to a shop.

Thank you!

P

I'm beginning an amplifier project. Some transistor matched pairs are difficult to find. So, I have some questions. How many transistors should I buy in order to end up with one 2 matched pairs? Is the hfe data from a PEAK DCA75 accurate enough for matching? How close should the hfe numbers be, to be considered matched?

hi
I have a problem with a design that generates 205v at 30ma. I am using a MC33025 in a voltage mode push pull configuration clocked at 50khz. My problem is that the transformer is clicking during power up only and I assume that this is because its going into saturation, am I correct? my transformer is primary winding 3 and sec 40 winding, on a 3c90 bobbin. the supply is 24v nominal to get 205v output. all is ok once up( no clicking). note the ramp signal is controlled and I have a softstart 10Uf cap. It takes a few seconds +6 to reach max voltage
how do I avoid this clicking? would increasing my turns help say 6:80 or 12:160?
any help please
Regards
Ross

Anybody got a schematic for a 70's vintage Systech 7012 Flanger?

Hi,

I got a Wharfedale Diamond 230 from a fiend for crossover upgrade...
It has a low cost crossover with iron core inductors and electrolytic capacitors bypassed with cheap polyester film caps. It measures good... probably, but sounds relatively bad...

I measured the inductors with LCR meter and rebuilt the new crossover with Miflex polypropylene capacitors, Visaton and Ohmite audio resistors, and Visaton air core inductors.

The new crossover parts costs about half of original speaker price! (~180 Euro)
Part list:
Capacitor MKP13-22U/400 MIFLEX 2 pcs
Capacitor MKP13-4.7U/400 MIFLEX 2 pcs
Capacitor MKP13-1U/400 MIFLEX 2 pcs
Capacitor KFPM01-0.1U/600 MIFLEX 4 pcs
(copper foil bypass cap for tweeter)
Resistor MOX-1.5R/10W-VS VISATON 2 pcs
Resistor MOX-10R/10W-VS VISATON 2 pcs
Resistor AG10-2.7R-5% OHMITE 2 pcs
Inductor SP-0.68MH48-VS VISATON 2 pcs
Inductor SP-1.5MH58-VS VISATON 2 pcs
Capacitor MKP13-27U/400 MIFLEX 2 pcs

The original inductors are 0.61mH and 1.3mH so I modified the inductors to match the original value.
See before and after pictures:
Original crossover:

New crossover:


It sounds completely different from original, with more detail, precise treble, better midrange and faster bass...

March 13 1945 - May 29 2020

Quite the dedicated speaker designer.

I remember selling a Audionics CC-2 amp to him thru an add I placed at the time
in the early 80,s

He showed up in a van with a single speaker he was taking around to various hiend shops getting opinions and advice for production.

He came along way since then and condolences to his family and close friends

Sincerely
David

Do you reckon this board would be good?

https://www.ebay.com/itm/283975094118
The idea is to use it as a part of a preamp I'm building. I've been very happy with the sound quality of the Fiio BTA30, which has the same Bluetooth chip. I don't know the rest of the insides of the Fiio, though, so I don't know if expecting similar sound quality from a board like this is in any way realistic?

bonjour, moi aussi j'ai le son coupé quelques secondes après l'allumage. J'ai remarqué que le condo C312 avait explosé (voir photo)

J'ai l'impression que l'opération va être compliquée à réaliser, avez-vous des recommandations à me faire, et pouvez-vous me confirmer par la photo que c'est bien le C312 qui est HS, et que c'est bien un condo de 10 mf de 50 v. Avez-vous une Réf à me donner pour commander ce condo?

Merci de votre aide

I've been trying to learn AKABAK 3 recently and found the lack of having all learning aids in one location quite a hinderence. Example my install did not seem to carry the SP20 sealed enclosure files and I did not notice the 'videos' link on the AKABAK site.

So here I propose to list all useful learning aids for AKABAK. If you have some to share, please do!

1) SP20 sealed enclosure video tutorial - VIDEOS HERE Files can be found in the 'No Installer' ZIP file here

2) Watch all the other AKABAK VIDEOS, they are only short.

3) Panson_hk examples on this forum. Post 2 and Post 11 . Download the files and study the elements in use.

4) Simulating a waveguide by Austin Mys VIDEO HERE. (Check out his other good videos). You will need a CAD software to draw your waveguide like Fusion 360. I have dumped an example project file attached WG44.zip.

5) Waveguides can also be generated by the software ATH4 HERE that outputs ABEC (AKABAK compatible) project files. I found the tutorial for ATH4 HERE helpful in understanding AKABAK BEM, too.

A couple of tips for issues I struggled with:

Error: RPC server unavailable - The connection between AKABAK and VACS (the viewer program) is broken. Restart VACS and click the VACS icon in AKABAK to establish a connection.

VACS looks tiny in 4K resolution - Stick this 'manifest' file in the same directory as the VacsViewer_64.exe file (file name must match). Then start VACS manually then click the VACS icon in AKABAK to establish a connection.

Frequency response has roll-off - If you create a project in BEM using a mesh as 'driven' to represent a speaker, or use the 'diaphragm' component, or a 'pressure box' component, but do not link them to a LEM model (i.e. they act as ideal pressure sources with no T/S parameters) you will by default have a bass roll-off. Go to the menu 'Global' > 'Fixed Driving'. Set 'Weight' to 'Divide by jw'. At default the ideal pressure source has constant velocity, which means at low frequencies the 'driver excursion' is smaller. This setting sets a constant energy spectrum instead of constant velocity.

That's all I can think of for now. EDIT: Can't believe I forgot Panson's posts on this very forum! Added now.

I'm selling my Pass B1 Buffer. It's assembled and in a "love it or hate it" enclosure 😀. You can have it with or without the enclosure.

It's 99% functional - one of the RCA input jacks seems to be loose and the signal will loose contact. Easily fixed if you have some time and some solder.

Apart from that I think the built is quite nice with high quality parts: Jantzen Cross Caps, Vishay RN Resistors, Alps Pots, etc. C1 and C2 are only 30mm high so the whole thing should fit in an enclosure with internal height of 40mm.

I'm having a hard time coming up with a price but i believe 60 USD would be fair.

I'm based in Europe but can ship it worldwide.

Found this vintage newcomb record player that had a tube amp inside. I decided to pull the amp out to investigate its potential. I haven't powered it up. I was thinking this would be my first restoration. I build my own passive crossovers so I'm thinking this would be the next step for me. I'm aware of the dangers of tube gear(high voltage). Does this look like a good candidate for a great sounding tube amp. How would it compare to the likes of fisher and Harman kardon?
There is an identical unit for sale a few hours away, I was thinking of making mono blocks from the pair. Maybe removing a lot of the tone controls, volume, making them just straight power amps.

Hi, I am working on a Icepower 1200AS2, and my prototype is getting quite hot. My case is going to be all aluminium. What do you suggest for mounting the board in the case.
1) Directly on the buttom of the case witn thermal paste to help dissipate the heat?
2) Put spacer so air will flow under the board
3) put a silent fan

thanks

For sale Salas Simplicistic Phono stage LMC 63db version with Teabag Pcb's, Nichicon Muse capacitors and MKP1837, all parts from Mouser. Silver mica and K73-11 signal capacitors. Load resistors are generated by an LDR resistor replacer.
The phono stage is powered by a Paradise Pre-regulator from GB Diyaudio, a small LDR power supply has been added. The original BLOCK transformers are not rigidly fixed to the PCBs and foam and lead have been added to make them even quieter.
The whole is connected with a professional connector, is perfectly functional and sounds great. I am selling it for lack of time. In the last 2 years I turned it on about 10 hours in total.
In the state in which it is found in the photographs, I sell together for 350 330 euros + shipping and Paypal fees.
Best regards
Guglielmo
Italy

Shocking how the price of gas has gone up... on the bright side it takes far less time to put in 20 bucks worth...

There are some commercial and diy power amplifier with an operational amplifier as front end.
At some of them the signal pad comes from the regular OP-AMP output.
But there are a second kind of signal out.
In this case the normal output from OP-AMP goes of GND (resistor between 100R and 1K) and the signal comes from the positive and negative PIN for the voltage supply.
What is the colloquial term of this topology and what are the pros and cons? (in post #4 one will find the right information).

I need this information to find appropriate design rules for such a front end on the web.
I asume, that the rules for replace the OP through a better version from currently production (like the LME series from NS resp. TI are not the same compare to cases, where the signal pad goes about the normal output.
Who can call me the term for this topology? Thank you for this information.
Here is a good description of this topology:
https://www.analog.com/media/en/tec...tes/58052492001115525484056221917334AN211.pdf

Hey guys, I have an old pair of Sony SS U501’s they have a mid range, tweeter and woofer. They look as if they have two woofers, but one is a blank - I put two new woofers in and wired them parallel I did not touch the mid or the tweeter, but I am wondering now should I change the wiring setup for those as well? Seeing I added another woofer, did not know if it would affect the mid and tweeter. These are 8 ohm speakers if that helps.

Noticed when looking at designs that some separate the sub from the full range drivers, giving them very little room to breathe. E.g

https://boenicke-audio.ch/products/loudspeakers/w5/

while others throw them all in a single box like the B&O Beolit: https://fccid.io/TTUBEOLIT17/Internal-Photos/Internal-Photos-3210730

Also seen people build the Isetta with and without separating the full range drivers: https://sites.google.com/site/undefinition/portable-and-tabletop-speakers/isetta

Anyone have strong opinions which way is better?

AFAIK it was only to eliminate radio interference, especially for the AM radio modes.
But how I can check the flawless operating when I have such a tape recorder for service ?

For sale a pair of SBAcoustics SB29NRX75-6 10" woofers from another abandoned project.

Absolutely like new. Just installed in a test box and measured and used like 10 hours. Original packaging.

Retail Price is 170€ each.
I'm asking 200€ for the pair +shipping + PP fees if apply

I am hoping someone can help a newbie. I am building Martin King’s open baffle speakers and have everything ready to go but have been waiting for Parts Express to ship the ERSE Super Q 4.0mH (0.22Ω) and 9.0mH (0.346Ω) 16 AWG 500W Laminated Iron Core Inductors for momths. However, I gather from reading a post here and from watching Danny of GR Research that Erse may not stay in business. I have looked around for similar inductors and am baffled (No pun intended). Can anyone help with alternative suggestions so I can get these speakers built?
Thanks,
Tom

Hello, I am in great need of help, as a diy Newbie i just don't know enough. I have a Vintage Tube amplifier - It's a Fischer Integrated Tube Amplifier that is missing the main Input Transformer, How easy is it to find a modern replacement and will it hurt the performance of the amplifier compared to the original main input transformer? It still has the two Output transformers, can it be saved? And what company would you recommend? -- -- Thanks, Dean

These are top spec plate amps. USD 300 each.

2 x 500wrms
1 x 250wrms

ICEpower amps

Digital programmable crossover

Worked great, awesome control of subs

This thread is dedicated to knowledge "learned today"...

I'll go first.

Today, I learned my Audio Techinica ATH-R70x are not only headphones, but microphones in parallel with the output (line and HP amp are the same output in this case)... If I hit them like a drum, my subwoofer mimics it. This isn't an issue, as I don't leave them plugged in, just interesting... I knew headphones were also microphones, but I've never had any that made LF.

Anyone got a schem for this puppy ?. Got one with a dead channel.
Cheers
M

I was wondering if there is any reason to try LED biasing of a 6j5 in a SE amp where this tube is the driver for a 6550? I am using a 1w resistor now. If i put the LED in how do i set it up other than just replacing the resistor? I know different LED colors correspond to different voltage requirements. Does that mean i need to select the color according to my voltage drop? Thanks for all the help.

I looked through my libraries with depressing results.
1/f is completely ignored, and noise above is "quite optimistic" if given at all.

Cheers, Gerhard

I've found some used LME49810s that I'd like to collect, but I'm having trouble judging if it's genuine. After the production was discontinued, the high price made fakes appear on the market~
Its font seems to be slightly different from 49830, and the stroke lines are a little thicker.
Sadly, for some reason, I'm currently unable to build a circuit to test it.

Previously, I successfully differentiated LME49830 quickly with reference to the experience of others. The pin resistance between VCC/GND of the genuine 49830 is approximately 60kΩ （Pin15 and Pin3）, and that between VEE/GND is approximately 40KΩ (Pin10 and Pin3).

Out of the same idea, I want to know what is the resistance value between VCC/VEE and GND of LME49810, can anyone help me measure it? thank you all😉