Looks like some kind of power supply/regulator. 4 power supplies and choke. I have no idea what its out of.

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Hi guys.

I rarely send posts, but I thought I would share this small project since it brought me so much fun, and musical enjoyment.

I know that tiny SE-Triode amps are not favored by the majority, but for those of you who happen to own (and apreciate) reasonably efficient speakers, this amp is lively, 3D and a real pleasure to live with.

I'm not knowledgeable alot about technology, but I'm learning.. So far, I've built a fairly nice 300B SE amp, a couple of 2A3 amps, and a Gainclone. All successful, and in no way, do I miss my previous Audionote 300B, neither my Audio Research (D70 yuk) or CJ.

This amp is the Shishido (loffin-white) 2A3.

Link: http://www3.sympatico.ca/wenchieh/2A3_schematics/shishido.jpg

It's easy to build. Almost no parts. I had build it with huge Hamonds 1627SE Output trannies, but lately I ordered 125FSE trannies, so I can substitute output tubes for 45 and WOW. Ok, it can play almost loud enough for most stuff. (with my Tannoys, and with Castle Chester) not very LOUD, but very adequate for every day use.

My 300B is the best "compromise", followed by the 2A3, but I must admit that with the 45s, everything lock in place, 3D image, timber naturalness, focus. A feeling of being there, especially on guitars, and on piano too. In fact, I love so much this amp, I might dig out my big 15" to see how it matches.

Well, this is it. I'm just excited at the idea of listening more and more music with it. A nice find, and by the way, these little Hammond FSE125 are real gems for a cheap price.

Hello to everyone! Newbie here! Hope you're doing great!

Decided to finally pull out from the shed my old analog mixing desk , it's an italian FBT 18SR from the 70's , 18 channels , I'm planning to use it for my drum kit , but before that, I want to test all channels real quick.


Being a very old mixer , it only has TRS jacks (mono) ,to test it, I was thinking to hook up an SM57 to channel 1's input , insert a mono TRS cable into one of the outputs (Either Mon 1/2 or L/R outputs and connect it to a guitar amp (in this case a VOX AV60 , or a couple of speakers (w/preamp) that use RCA jacks. Not getting any results , (because I have no idea what I'm doing) , so I ask you kind experts: what are the different ways to hook up this mixer to test it? Just to get a sound.. , I'm sure I'm making ridicolous mistakes!
Apart from trashing this old lady , I'm willing to hear your opinions!
RR/RS

Hello recently got an old saba 360 wkh radio with this sticker, and i have no idea what it means. Please tell me.

Hi

I have an Audiolab 1997 8000S and 1986 8000A, both of which are working fine.

However, the 8000S resistors 721, 722, (724, 725, 821, 822, 824 and 825) are visibly burnt. They seem to be 4 sets of parallel configured resistors to give higher power ratings. They have been obviously getting hot for a while as the circuit board is discoloured. My schematics are dated 2005 so are for the Chinese version amp. The diagram says these resistors should be 3K0. which in parallel, will be 1K5. Actually, with my amp built in 1997, they are 2K0, so have a total R of 1K0.

The 8000A circuit is similar but not identical. It has 3 x 4K7 resistors in parallel
(R447, 449 and 451 according to my circuit) to give 1k56, which is similar to the Chinese version of 8000S.

Using a DVM, there is upto 32V dropped across the resistors in the 8000S, giving a power requirement of about 1Watt which might explain why they are burning.

Although I have made measurements etc, Im no Designer.
So what do these resistors actually do?
Will changing them to 3K0 on the 8000S be a good idea, so as to reduce the current and therfore lower the wattage needed?
What effect will this have on the sound of the amp, if any?

If I had to restart my hifi hobby and could keep only one component that I own now - it would be my DIY Moskido amps which sound better than any amplifier I have ever heard. I completed my Moskido amps about the time the Moskido thread disappeared from DiyAudio which may have left a few persons stranded in the middle of their Moskido projects. The purpose of this thread is for the DiyAudio community to help each other complete their Moskido amps.

For those of you who are new to the Moskido amp design – building one of these is for the advanced audio DIYer. All the Schematics for the Moskido can be found on Bob Prangnell's excellent Mad Scientist Audio web site in the DIY section. The heart of the Moskido is the Aikido gain/driver stage. Aikido boards/kits can be purchased from Glass-Ware through the tubecad.com web site.

Bob Prangnell's schematics are for a 50 watt/channel class A amp using a 6SL7->6SN7 Aikido and a double pair of complementary MOSFET power transistors. I originally built a 10 watt/channel Moskido using a 6SN7->6BX7 Glass-Ware Aikido and a single pair of MOSFET power transistors. I recently designed a 7193->6BX7 push-pull Aikido PCB which is discussed in a separate thread (http://www.diyaudio.com/forums/anal...6bx7-push-pull-aikido-preamp.html#post4653656), but has a voltage gain of only 7.7x which works great with my 98db efficient speakers. Judging from the heat produced by my 10 watt Moskido, the 50 watt units must be serious room heaters.

Edit: The new Bias PCB has been working great for 2 years now. The Obligato Gold coupling caps sound amazing. Vocals have never sounded so natural on my Moskido amps! The Bias PCB eliminates the nasty project step of bread-boarding Bias boards from a schematic. I can also email the Eagle files to anyone who is interested in them, however, this PCB includes at least one device that I created in a lbr file. The BOM and instructions are complete. Because I am not allowed to change/add attachments, please go to last post for more information.

Hi

Does anyone has a schematic for this RCF Art 712 powered speaker. I need this schematic badly.

Thanks

I'm hoping to find schematics for a Sony TC-200, SN 29422, hybrid. Mechanically it is in surprisingly good shape. I'm a newbie here so I didn't know which forum would have covered this.

I have a nice R-Core 30VA 24V transformer that I want to use that should give 24x1.414=34V. The problem is I need between 25-30V for the preamplifier I'm planning on powering.

I usually use SMPS so don't have much working knowledge of how linear PS work. How can I reduce the power safely?

Alex was a longtime member of DIY Audio. He passed away April 2nd. from complications of cancer surgery. He was a major contributor on Rock Grotto Forum.
Among his accomplishments were the improvements to the Jaycar desktop amplifier, great improvements to the JLH Ripple Reducer & making a stellar Headphone amplifier from a bog standard 15 watt unit to an extremely high quality unit that w2as considered sonically equal to a $33,000 preamp.
He will be sorely missed!

I could use some technical help. I have some relatively new Lux91 Mono Blocks (arrived in March). The amps have been fantastic until yesterday when one channel cut-out. I checked the fuse and it had blown. I have since replaced the fuse a couple of times and it immediately blows when the switch is turned on. I removed all tubes and inserted a new fuse and it still blows every time I turn the amp on. I have visually inspected the internals and nothing looks to be out of the ordinary. Can anyone walk me through some quick checks /diagnostics to isolate the problem.

Any help would be greatly appreciated.

Thanks

I realize that I don’t have the foggiest idea how digital audio is transmitted, at the basic layers. How is it steamed from a device to a network steamer? How is it transferred to a DAC? What protocols are used, how is transmission failure or errors handled?

Feel free to link me to articles, I know I’m asking very broad questions. I don’t know where to jump in.

I got these in a plastic cinema speaker (JBL 8340A). Unfortunately (and as expected), the foam surrounds have disappeared. The 127H-3 looks like a speaker worth refoaming - anyone any experience with this model? And these could serve as party boxes that could be permanently installed in my second garage with their nice wall holders.

I wonder how critical is the foam/rubber to be used - will a generic one do if having correct dimensions?

Does anyone have any experience with using passive radiators for musical instruments? I was thinking of building a passive radiator box for my bass to keep the box small and get good lows from a 12" speaker.
The radiators I've seen are all foam surrounds and I'm thinking I'll be blowing the cones into the grill cloth 1st big notes I hit.
Why would I want to do this? I have a bassman with the crappy oxford 12" and I want to replace them with something that will give me good 40Hz response. The bassman box is very small, but it fits in my Camry, which is nice. Otherwise, I'll just replace the oxfords with a pair of eminence basslite 12s for about $160US.

I have tube pre kit which (supposedly) works with any of these. Which is most linear? Most musical? Or otherwise preffered?
I can get some or all, and compare, but even different supliers can result in different sound.
Any recommendation? They do have different heater current demands, so i have to account for this.
I already have one working in box and second is up and running on the floor. I want to replace all my solid state pre, as this pre has more musicality for me. I got no schematics, sorry.

I got boxes of old ( mid 80s to Y2K+) Stereophiles, TAS, TPV and SGTHT.

And after years of looking at those boxes taking space that could be use better, ie: MORE audio stuff, I figure it's time to get rid of that. I will never read them again. (*) so time to give them the heave ho.

But they are in very good shape. I doubt the library will take them and I've seen them sold on eBay, Craigslist. But it's a PITA because I got other things to do with my life.

It's doubtful The Salvation Army, et. al... will take them.

And, I'd hate to put them in the recycle.

Any ideas? I'm not in for the money, OK, if you give me a nice F5 Turbo V5 and a Marantz 4140, I might... ;-)



(*) Like everything else, I know once I get rid of them, then I'll want to read them. 😛

I'm looking for an ic replacement of TDA1514A

Hello--

Apologies if this post is not in the right place or is otherwise inappropriate.

My last order from an eBay seller I've used a few times was placed the night before Putin announced his invasion of Ukraine. The seller is a Russian gentleman who has always provided excellent prices, shipping, packing, communication, and so forth. His seller name was/is "12-ROCKETMAN".

I followed up after the order with how he was doing and he explained that he has moved his operation to Kazakhstan and is stressed out due to being blocked from selling on eBay. This morning, I received a message explaining that, as he does not have a storefront website, requests for tubes should be sent to his personal e-mail. I wanted to provide his message in case anyone here wants to order Russian tubes but is no longer sure how to do so:

Dear CUSTOMER, due to the temporary blocking of sellers from Russia, buying on the Ebay website is not available. If you want to BUY TUBES from RUSSIA, write hаtа429 (gmаil) , I will reply to your MESSAGES. Sincerely 12-ROCKETMAN

Click to expand...

There seems to be a very low interest in room acoustics in this forum, can you recommend another forum that has more activity for this topic?

thank you!

peace

I've used fairly expensive Mundorf, Jantzen and Obbligato caps for my outboard crossovers and now need to buy a few more caps to complete a modification. So during the cap search I came across Dayton Audio PMPC 250V Precision 1% caps and was amazed by the low cost. Dayton caps cost $4.11 each which is fraction of the cost of Mundorf and Jantzen caps. Did I waste a lot of $$$ buying the designer caps?

Hi,
I am looking for a converter kit from HDMI to I2S. I will connect the HDMI out of my laptop to the input of HDMI to I2S converter and will get I2S signals. Then i will connect the I2S out to my TDA1541A dac and listen music. Anybody can recommend me such convertor kit? Any comment welcome.
Thanks

Due to an excess of equipment, and because something really big will come to my place, it's my sad duty to put for sale my USHER RW-729 bookshelf speakers.
The speakers are made by hand with solid walnut wood in the style of the Sonus faber Electa Amator and with a spectacular finishing and incredible quality.

Some webs says they were created and voiced for Usher by Josehp D’Appolito, but I cannot confirm this.

Minimal marks on the wood, mainly on the cabinet bases and nothing appreciable to the naked eye.
Stautus like 9 out of 10. Perfect working condition 100%

They play with an impressive dynamics and a spectacular midrange and treble, also providing incredible bass for monitors of this size (23x44x39 cm) and 87/88db of sensitivity.

Each cabinet weights like 17 kilos.

Asking 900€ without stands. Really bargain price that I will no lower.
You have to add Paypal Fees + shipping (near to 50€ within EU)

I am looking for a 4 digit LED or LCD panel that can measure and display Volt and Ampere on two different rows, typical range around 0-50 Volts and 0-10 Amps for an upcoming DIY adjustable bench PSU, anyone aware of any DIY V/A meter project one can modify and build on, or hinting on some suitable components like what kind of uC (PIC, Arduino..?) with built in 2ch ADC that could fill the function, or whether there are some dedicated all in one chips, alternatively a ready made display from eBay etc., although the DIY challenge allures me more.

The only one suitable display found on eBay, AliExpress, BangGood is a generic model sold in the multitudes usually for ~5$€£, but the digits are tiny, if I understood the info it says 0,28" (= 7mm) that's the height, but sure these 7 segment LED's could easily be changed for much larger ones.

DC 0-200V 10A 4 Bit 5 wires Amp Dual Digital Blue + Red LED Voltmeter Ammeter
https://www.ebay.com/itm/264505980309
https://www.ebay.com/usr/technicalaim


BTW found an LCD too, but not sure if it's 4 digit capable although the pictures indicates so, the info is a bit scares.

DC 5-24V Voltage Current Meter Detection LCD Display Ammeter Voltmeter DC 0-100V
https://www.ebay.com/itm/274447916721
https://www.ebay.com/usr/modul_technik


Below some LCD's, like them and they have 'V' and 'A' letter in the display but unfortunately it's AC only.

AC 40-400V 100A Digital Voltage Ampere Panel Meter 220V 110V Ammeter Voltmeter
https://www.ebay.com/itm/402895802827
https://www.ebay.com/usr/technicalaim


AC 40-400V 100A Digital Voltage Current Power Factor Meter Voltmeter Amperemeter
https://www.ebay.com/itm/233975732084
https://www.ebay.com/usr/elezone17

I am in the process of restoring this Sherwood S-9500c. When I got it, the amp would not power on because of a blown main fuse, the replacement also blew so I traced the problem to a defective rectifier diode and got it to run. I then replaced three power supply electrolytic capacitors, each rated at 500uF since none of them tested near spec. The main filter capacitor, 3000uF remains in place for now. I also replaced the two output caps since they were not original and tested over 50% higher than their stated values.

Listening revealed audible distortion in the LEFT channel so I tested all of the caps and found one bad cap on the main amplifier board. Replacing it did not solve the problem so I proceeded to replace all of the electrolytics in the preamp, tone and amplifier boards. No change, I then started to test the transistors with this handy Peak Atlas Semiconductor Component Analyzer and one transistor in the amp board tested as a diode so I assume this could be the problem.

If I am reading the schematic correctly, the transistor in question is Q205 (SPS41). The transistors on the amp boards are stamped "TP" "109C". I've attached photos and the service manual.

What would be the appropriate replacement for the SPS41 ?

..........BEFORE..........



..........AFTER..........



BAD TRANSISTOR

Hello all,

For Sale: - Fully functional Weiliang DAC 7 - Wolfson WM8741 based DAC was built years ago and was my reference for Digital input before replacing it with a much more expensive AMR DP-777SE DAC. This DAC bested all others I tried and was happy for years...

But no longer need it - these DACs were all the rage a few years ago, with lots of mod possibilities - I preferred it stock with LM4562 Opamps as opposed to those who wanted different Opamps or a tube back end...

I added a USB converter and works great too...

Inputs:
Optical (TOSLINK)
Coaxial
USB

Pics forthcoming

How's $150 + ship?

Hello everybody,

I have a friend of mine who is a skilled tech to build me a Pass Labs First Watt F4 clone which I will use coupled with my vintage Audio Research SP9 preamp, on the excitement for the renewal of my stereo setup I kept scratching my head and ended up looking at the 120+ pages of the BA-3 front end used as a preamp and is looks like it would be a perfect mate for the F4 and not too difficult to put together even for a beginner.

Not to pollute the dedicated thread with questions about the power supply I am starting one here so that you can help me figure it all out.

As far as my understanding it takes a transformer to go from 230AC (Italy here) to the expected AC to feed the preamp stage rails, something like:

• transformers (I'll like to make it dual mono since also the F4 is gonna be so)
• rectifiers (dunno if the PS boards act as rectifiers too)
• power supply boards
• BA-3 board
• volume pot, AC switch, input selector, RCA plugs, AC plug, cables...

Here about the power supply boards, so far it seems doesn't matter which, it has to feed in the 18-24Vcc and if I got it right the desired output gets adjusted by the components on the PSU board, I see many implementations but to make it easier since I need to buy the BA-3 board off the DIY store I might also get the Super Regulator one(s) and combine it all within one shipping, am I correct that the latter board would do it and that it takes two to make a dual mono setup along with two single output transformers?

I see that the board comes with holes to fit the cables coming out of the transformers but on several finished setups there are screw terminals (sorry, dunno how they are called in Enlish), my guess is that the greed sockets have been soldered on the board then cables plugged in is that right and are those green things a standard size I can get off any components supplier?

Thanks for your attention

Giovanni

I'm new to using this forum. I'm having an issue finding where to initiate a personal message to another member. My thanks for any help.

In a recent woofer update in particle board boxes, I examined any and all options:
T-nuts, threaded fasteners, wood screws, sheet metal screws, clamps, etc. None of which offered an optimal solution due to the mounting circle diameter relative to the cutout.
T-nuts should be pressed in. Threaded fasteners require sufficient margin of which there was little. Wood screws waste a fair portion of their length. Clamps don't apply the full force to the driver. Which left sheet metal screws.

The particle board, of which I have zero expertise, is covered with a hard outer shell, seemed softish in the middle and harder on the inside. The original install used straight #8 Philips head screws. It appeared the holes were originally drilled at the recommended 80% root diameter as the surface was pulled up which is not ideal.

Countless hours perusing online fora didn't ring any chimes.

I came across this by chrisb wherein he suggests using Crazy Glue to harden the particle board fibres prior to insertion.
⚡
Cogitating a bit, I reasoned that a good wood glue in a root diameter hole might be just the ticket.
And lo and behold, it's perfect!!

Method:

1. Accurately mark and double check driver mounting holes
2. Accurately punch hole centres
3. Drill root diameter with brad point drill
4. Using a slightly smaller drill, fill the flutes with a good 24 hour wood glue and coat the holes thoroughly
5. W a i t ... let the glue set
6. Using a sharp metal drill slightly smaller than the root diameter in a tap t-handle, gently clean the excess glue from the hole
7. Vacuum any detritus from the holes
8. Wax the mounting screws [I used candle wax melted in a pan of hot, not boiling, water]
9. Place driver
10. Insert screws and tighten just shy of contact
11. Follow flange bolt tightening sequence, preferably with a calibrated driver

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😀