I have two microwave transformers for 230v mains. they are gaped to support DC

could one be used as output transforemr for SE triode amp ?
230v secondary is maybe good for 16ohm speaker?

I was hoping someone could explain how to hook up this amplifier Pioneer GM-H120...I was reading an old thread and apparently this amp has something called a floating circuit. You have to ground the "shields" but I don't know what SHIELDS mean???

I have an Audio Apex CAB45 that stopped working. When I try to power on with 12v it only flashes on and off very fast. However it will power on and stay on with low power at about 9v. No blown fets and no visible damage to any components. Does anyone have any idea where I should start looking? Any chance it could be a relay? I also do have another of these in working condition that I can use to test any difference if needed. Thanks for any help.

Hi, can anyone pls advise the brand/mfgr name of the capacitor ? Tks ! Richard

Anybody knows the reliable source of laser head for Pro2Lf mech? The whole units are getting really expensive and it does not look like they will get cheaper..

I’ve got a project in mind that hasn’t progressed to even a sheet of paper. It’s for the long term since I’m broke at the moment, but it’s fun to plan for when I’m no longer broke.

I’m considering a three-way using an 18” woofer in a sealed cabinet. What is the spacing above the floor that I need in order to couple to it? While I’m at it, I might as well ask about the center-to-center distance between the woofer & midrange at a crossover frequency of 500Hz with a 12dB slope.

Thanks, as always.

SOLD
Last spare set of Miro AD1865 DAC for sale. i2s inputs on board.
Circuit design and board info available here:
https://www.diyaudio.com/community/...2s-input-nos-r-2r.354078/page-72#post-6525201
You need a PSU and I2s source and a pair of single op amp for this DAC to function. I will not be providing the IV op amp, the op amp on the board in the picture is for illustration only.

Price is $xxUSD, and it covers the registered shipping worldwide from Singapore.
I have sold and delivered almost 30 items successfully to Europe, UK and US with zero problems.
My preferred transaction would be PAYPAL FF only. For members who are unable accept this mode of payment would have to skip this deal, i am sorry.

Dear all,

I am an electronic engineer with several years of experience in the industry. I've recently embarked on a new project aimed at creating a two-channel rotary mixer. In essence, this mixer will feature phono and line inputs, kill EQs, and a HP/LP filter. I have extensively studied the service manuals available on the web (such as RANE and A&H Xone), and I've gained a clear understanding of how to handle most aspects of this project. However, I have a question that remains unanswered: how should I manage the channel level?

In modern mixers, the mixing section typically incorporates a VCA (e.g., SSM2164) controlled by the crossfader and faders (in some cases, the VCA is solely controlled by the crossfader, while the channel faders are directly integrated into the analog path). This design is implemented to reduce the noise floor and increase tolerance to potentiometer wear. In a rotary mixer, there is no crossfader, which has led me to contemplate whether I should retain the VCA for channel level control or incorporate the faders directly into the signal path.

what´s your opinion?

I'm wondering: Is there any rule of thumb for estimating continuous power dissipation in a speaker you're building from scratch?

Say you got a magnet and a basket with absolutely no information whatsoever about the power rating of the previous speaker.

Once you get a voice coil for it, the main surfaces involved in heat transfer will be already defined: The lateral surface of the wire coil itself, the surface of the voice coil former (important if its aluminium) and the surface of the top and bottom plates of the magnet.

Obviously, air flow in the speaker as it moves is very important for cooling, and things aren't easy to estimate if it's a vented pole piece.

But I'm just looking for a rule of thumb, and for continuous power dissipation, not transient (in which thermal masses matter a lot).

I could try to find a pattern across several speaker datasheets, if they have all the dimensions (including voice coil height) plus voice coil former material.

But I thought that perhaps someone here might know about some easier way to do it.

Hi, I have been trying to build up a 240VAC transformer unit to run a phono stage. The trans is rated at 36V & 300W, but when connected to the mains it is massively putting out 48V.
So to reduce the voltage to the required 36V, I inserted a 240V voltage reducer, before the phono trans mains lead. (I bought for another project into the mains circuit, but did not end up using it) To get the Trans output down to 36V I had to reduce the mains down to 180VAC.

I have tried the phono amp out in this format I it works very well, however the trans gets very, very hot (still touchable, but only just) so I have only used it for short periods of time because I do not want to burn the unit out!!

So if I can ask for guidance,

• How hot should a trans get.
• Is there a better way to get the trans to operate, I have read inserting Schottky diodes in the output line can do it. But do not know how to configure this.

Cheers for any help, suggestions.

I am fascinated.
I get that I am late to the party but wow!
How many others here watch?

Very low use. They just didn't have enough amps for my amps. Leads are still original length except one which has the original insulation (just the wire cut). I think these put out more than 150 MA.
100.00 for the pair plus shipping and paypal fees if used for product and service is used. Personal checks OK. Local pickup welcome in or near Angleton TX.
Thanks for looking OB

I have this Darkvoice headphone amp that sounded great for about an hour until one of the Chinese tubes failed in one channel. Actually, it looks like BOTH tubes triode sections failed for the same channel at the same time. Neither the 6SN7 for that channel or the 6AS7 for that channel is drawing any current. The other channel works. Is it possible that the 6SN7 failed and took the 6AS7 with it, or the other way around? (see attachment)

Hi All. Anyone has tried any of these 2A3 tubes available on AliExpress? Linlai, Guiguang, PSVane, and Fire Crew all make versions of what they call 2A3B, 2A3C and 2A3D. The primary difference between the letter designations appears to be the shape of the envelope. Any experience or reviews with any of these tubes would be appreciated.

I have wanted a convenient power amplifier that could be used for stereo playback, multi-channel playback, or in a powered speaker. However, this project has been on hold for about a year. For continuity, my original posts on this subject can be found at the following link. Also, thank you to members AndrewT, marce, and tomchr for their previous responses and helpful links.

http://www.diyaudio.com/forums/chip-amps/251542-lm4780-pcb-layout.html#post3866237

The following layout is meant to provide configuration options (stereo or parallel amplification) when using a stand-alone LM4780. The inputs could include RCA or XLR connections (via an external THAT 1200 board). The potential sources are a preamp, a music player, or an Analog devices ADZS-21469 DSP evaluation board.

The layout below is based on the Texas Instruments (LM3886 and LM4780) data sheets and National Semiconductor application notes (AN-1192 and AN-1849). The output inductor and resistor are connected off-board following the placement considerations raised in chapter 8 (starting on page 235) of Douglas Self's "Audio Power Amplifier Design Handbook 5th edition". The on-board grounding scheme follows the Taming the LM3886 Chip Amplifier article by tomchr on the Neurochrome website and allows for off-board grounding if needed.

While the general layout is basically settled, there are a few questions that I would like to resolve.

Q1.) What is enough space for heat sink mounting? Can anyone verify the spacing between the back hole centers of the LM4780 and the back edge of the board? For reference, I am using 160 mils as pictured.

Q2.) What is the typical spacing between the power rails to satisfy clearance and creepage safety requirements? For example, figure 40 of the LM4780 data sheet layout appears to use approximately 40 to 45 mil spacing while tables two and three of "Safety Considerations in Power Supply Design" recommend 16 to 47.2 mil (or 0.4 to 1.2 mm) depending on functional needs and pollution level.

Safety Considerations in Power Supply Design
http://www.ieee.li/pdf/essay/safety_considerations_in_power_supply_design.pdf

Q3.) Are there better small signal and ground plane routing alternatives? In the example below, the small signal wires are on the bottom of the board and higher voltage signals are carried on the top. Can anyone provide measurements or experiences when routing the small signals on top and using an isolated small signal ground plane on the bottom?

Hello all. I'm new here. I don't know anything about circuit design. I'm an audio engineer and have soldered a bunch of cables (not that that really matters though).

I bought two Western Electric 111C transformers to run my mixes through. They sound good but I want to really push them. Problem is the SSL compressor clone I have before the 111C craps out at +22dbu. The 111C can handle +30dbm.

I've looked at hundreds of preamps online and only one has a max output past +28dbu and that's the Avalon Ad2022, but it's like $3k +. I'm thinking there has to be a way I can build a little box that can boost a +10dbu 600ohm signal to a max of around +35dbu 600ohm. Also the signal has to be balanced in and out, preferably XLR. I need two channels. A fixed gain boost would work but something with a gain pot would obviously give me more flexibility.

If anyone can help I'd appreciate it. I can do some soldering work if there's a kit, or I can pay someone to build it. Or it would be great if there's already little kit out there. Any help is greatly appreciated. Thanks.

So I'll try to keep this brief. I have been trying to fix this amp that doesn't want to power on.. Yes I have read all the posts and seen the most common problem with this series is the cap 196 that is part of the start circuit. this was a design flaw from factory and changing it usually takes care of all the problems. No luck. What is making things the most difficult is that all the circuit is very small surface mount. It seems from measurements that I'm not getting the Kickstart signal that should occur with the SMP power supply. I'll attach schematic. Looking at page 6, power supply. All my measurements are referenced to V_BULKRTN. At power on I get ~168vdc across the main caps after the bridge. At TP31(C8) I get 0vdc. At the top of the resister divider feeding V_KSTART I have 168vdc and at the midpoint of resisters 84vdc. So testing the Zeners, D28, D29 in circuit both the 16v diodes test good .7vdc forward and open on reverse. The D25 tests good also in circuit. I also notice that I never get 30v_CTRL and thus no 15v_CTRL. That goes to alot of stuff. So that is a good start. One question where does the 30v_CTRL originate?? Is it the power transformer circuit at B6?? But that is the primary so not sure?
I have many years of repairing equipment but almost no experience with SMPS supplies. Understand just a little from Youtube. Anyway this is a very common problem with this line of Crown amps. But not the capacitor it usually is.

Hello folks - I was wondering if someone could help me clarify what I was reading in a post regarding hum pot use with a 2a3. I have tried to draw the schematic that a poster was describing but think I have it wrong. See photo below and any help is appreciated!

Apologies!! These quotes were from Palustris (left) and Kmaier (right).

Hello, today I bring the fateful DWM1216X_V20 driver back to the surface. I have a Zapco SP 2000.1 in my hands with a blown channel.
After ordering the IRF640 (non-N) and IRF9640 mosfets I would like to review the drivers as well.
I would like to replace the following:

• MMBTA42 (1D)
• MMBTA92 (2D)
• 2SC4672 (DK QU)
• 2SA1797 (AG QS)

I can recover the two MMBTA42 and MMBTAA92 transistors without problems, instead, the 2SC4672 and 2SA1797 cannot. Can they be replaced with 2SA1213 and 2SC2873?
Has anyone ever had a similar problem?

PS: Wandering around the Internet I found on a Russian forum a schematic of the aforementioned card that mounts on Hifonics.
On that scheme instead, the BCX56 and BCX53 are used.

Some idea?

Hi guys,Im looking to buy some Panasonic erx 0,47 metalfilm resistors that I need for my build of Aleph J amp.Plese if someone have some 16 pieces for sale,just contact me .😉

In this thread we will discuss current vs voltage drive of loudspeakers in an open and friendly way.

Here is the EDN article to kick the discussion off.

http://www.edn.com/design/consumer/...periority-of-current-drive-over-voltage-drive

I've put it here under solid state since we want to discuss not only the transducer and acoustical aspects, but also the amplifier and sensing requirements.


😎

Hi,
I found on Aliexpress such a ready-made stereo amplifier kit on LM3886. Does anyone have experience with this board? Is it a good option for building an amplifier?
https://a.aliexpress.com/_EvUjjCB

Dear All,

I have a Accuphase P102 that I recently purchased, unfortunately there were some bad soldering points, that has been taken care of, but now one of the power transistors went up in smoke... anybody any idea how this could happen? Bias is measured at 200mv seems a little high!



Does anybody know what the bias should be?

Does anybody know if there is a service manual available?

thanks so in advance for your help!

with regards

Joris
the Netherlands

I would like to add a sub to my main speakers. The system sub I have, collecting dust, is part of the Fried model H . Its a 2ch dual transmission line woofer and because of its size, its affectionately called the Coffin.
The Xover for it and the 2 satellites are located in an external Xover box. The woofers are 8ohm Kefs B200's.
That sub goes way down and the LF is robust, articulate and very smooth. I've always missed their bass performance. You can find a full description here:

https://www.t-linespeakers.org/classics/friedH/fried_H.html

My 4ohm main speakers here:
https://www.theabsolutesound.com/articles/bud-fried-tower-loudspeaker/

The monster coils form a 100hz Xover. I would like to try and make a first order 100hz xover and see what it sounds like when paired with my mains: Salk/Fried commemorative tower speakers. My amp is 550w, so plenty of juice there and all speakers will be fed from it. I know there will be a lot of overlap and efficiency concerns but would like to try this inexpensive option without damaging the mains or the amp. Perhaps an L-pad?
I'd appreciate all the help offered.

Thanks

Hi,
For those looking to buy Texas Instrument LM3886 Mouser have 4500 in stock.

link:https://www.mouser.com/c/?q=lm3886

Hi
I build my aca's at the first ever amp camp back in 2012. They have served well for over a decade until recently when one of them stoped producing. I checked all the obvious external connections/wires and source and they are all good. I opened it up and that's as far as I've gotten. I don't know what to do next. It is my understanding that is the very first version of the amp. Hoping to repair it so I can pair it back up with the other one and keep on listening.
Thanks for taking interest.
Joe

Totaly new build with 12 inch. Tannoy drivers from Srm12x enclosures the 3149g gold drivers. With new Mainley Tannoy crossovers with Jantzen coils and mkp crosscap capacitors. . The drivers have new surrounds from new prestige HE series, replaced by lockwood audio UK. Enclosure from Finnland birch multiplex, the best material for speaker building.The speaker building pist original tannoy!!! Verry nice work. Can be send inside EU in 2 packages. Payment thru paypal.Price 1250 eu or best offer plus shipping. Info over email.

So, after bugging out and living in the Australian bush for a few years and running into some issues with my landlord (covid profiteering), it has come time for me to re-enter society.
I have carted these components around with me for years, always planning to put them to good use, but I usually end up buying new stuff for my builds and pretty much exclusively SMD these days, so the pile gets larger and larger. I'm also undertaking a 3d printed smallsyns build 'unexpectedly' and would like to offset that.

Too many things to photograph all separately and the majority are in as new condition, but I will take photos of anything potential buyers wish to see (particularly the pulls and pics of the rare trannies to show legitimacy as I dont have the original full Toshiba boxes).

Prices are in USD, but if any Aussies want to purchase, i'm happy to just do the straight conversion (not paypal conversion, just pay me the USD price converted at the current market rate).
Most is not large enough to cause too much expense, or trouble with international shipping, so if you will pay it, i'll send it. Happy to accept USD via paypal also if you would rather avoid conversion.

I have tried to price things fairly vs current market rate by searching around and comparing to what I paid if I have records. I have not searched exhaustively for the cheapest new price (not clearance) so if you think something is priced too high and can show me somewhere it is cheaper, do let me know, maybe we can work something out. No comments on absolute value of some of the more esoteric items please, I wont enter into it 🙂 My own views have changed over time, but that doesnt mean I want to give them away (although I will very likely give some stuff away towards the end, maybe for a donation to the forum.

I will entertain deals for multiple purchases, just PM me.

OK, so time is moving along and quite a few (most) of the transistors have sold

Prices marked down again 22/06/22 priced to sell. Marked down and added package prices. Dont hang around for them to go down further. if you have a reasonable offer, make it 🙂

Toshiba NOS JFETS

100 x 2SK170BL = $240USD ONO SOLD Shipped

100 x 2SK170GR = $200USD ONO (PENDING) SOLD Shipped


50 x 2SK246BL = $40USD (PENDING) SOLD Shipped


50 x 2SJ103BL = $40USD (PENDING) SOLD Shipped


2 x 2SJ109V = $80USD $60USD for the 2 (used)


4 pairs of 2SJ74BL @ $20USD ea (think these were from Spencer, but I honestly cant remember. they are marked with values, will dig out for details if anyone is interested) I had the wrong price on these, my apologies.
SOLD Shipped


Semisouth

1 x Pair of R125 Semisouth = $180USD ONO (curve traced, turned out thanks to Patrick I only needed 2) SOLD and shipped



Film Caps

2 x VCAP TFTF 0.22µF/600V $200USD ONO (this is more than 40% off the current clearance pricing. these great caps are not available anymore)


4 x 0.1uf VCAP CuTF $480USD $450USD $350USD ONO (unused.. definitely up for sale now)


4 x 0.22uf Mundorf SIO $150USD $120USD $100/set


2 x Mundorf mcap 330uf 250v used $50USD $40USD ea


4 x Auricap PP 3.3UF @ $50USD $40USD/set


Will take $600USD for the lot, including the 2 vcap TFTF, which are 1uf IIRC (will unpack and find out, if anyone is genuinely interested)



Electrolytic caps

8 x Mundorf Mlytic 2200uf/63 @ $12.50 = $100USD/set $80USD/set


8 x Mundorf Mlytic 6800uf/63 = $140USD $120 $100 ONO

Will take $150USD for all 16 mundorf electros


Assorted Nichicon 'audio grade' caps. $50USD $40USD for the lot
100µF/25V KZ
100µF/50V KZ
220µF/25V KZ
220µF/50V KZ
470µF/50V KZ
220µF/25V FG



Blackgate
BG NXHiQ, N and standard.

Again I have searched around and priced these not insignificantly lower than what I was able to find and what ive seen in the past. I cant look everywhere though.

10 x Blackgate NX HiQ 47µF/6.3V mostly used. some remains of potting on a couple = $450USD $300USD ONO (will split out, ask for price)
4 x Blackgate NX HiQ 22µF/6.3V mostly used. some remains of potting on a couple = $80 $40USD(10ea) ONO
4 x Blackgate FK 47µF/16V used $100 $75USD(20ea)
3 x Blackgate FK 100µF/25V NOS $40USD each ($100USD for the 3)
4 x Blackgate Standard 47µF/100V used $200 $180USD $150USD(set)
2 x Blackgate NONPOLAR 100/6.3V mostly used. some remains of potting. look fugly, function fine. make me an offer.
4 x Blackgate PK 47µƒ/25V NOS I dont know what to ask for these.

Will take $600USD for all Blackgates



ELNA Silmic II, assorted values. $40USD the lot
2200/50V
470/50V
220/50V
100/50V





alps blue velvet Japan 50k stereo $15USD


DACT CT2-2 50K = $170USD $150USD ONO (lightly used)


ELMA 24 pos 1 layer 04 - 1100 - 20 1107 endless $40USD $30USD ea (2 pieces)


ConneX Socket 7 Pin Miniature CNC Machined *PTFE Chassis Mount Gold Plated 8 pieces = $100USD $80USD


Connex 7 pin ceramic tube socket x 8 = $40USD


Eharmonix 12AU7 x 4 = $70USD $50USD


ETI silver bullets $150USD $80USD set 4 (old style, NOS)




Furutech IEC rhodium FI-09 = $70USD $60USD ONO


Furutech FP-681-2 Gold XLR Panel mount female x 4 = $150USD $140USD $100USD/set




OK thats it for now. i'll go through the more industrial high quality stuff tomorrow to find some stuff to list.

This idea is based on the F5 Simplified schematic by Nelson Pass.
As it stands it is for 32 Ohm headphones.
The gain is a bit over 2.
Gain can be adjusted by R2 and R7 for other headphones.

Transformer can be 2x12VAC or possibly 2x15VAC.
The bias is here 227mA Class A and this gives a THD like 0.010%.

I want to wire my DIY el84 se amp, from triode wired to pentode wired. Can I use a switch to change between triode to Pentode?, and how do I connect the switch?
Love the sound of my triode wired amp, but I am curious how the amp sounds , connected as a pentode.

Despite the miserable recording quality, this recording of "Talkin' Bout You" from Hamburg in 1962 is just ferocious: up there with I'm Down, Long Tall Sally, Twist and Shout, Revolution and Taxman:

Login to view embedded media
Geoff

Hi Everyone,

New to this site and new to my recent acquired Luxkit Z501, beautiful sound BTW. Have already learned and collected quite a lot of information on that machine, I am currently looking to get my hand on the service manual just in case if I will ever needed to re-cap or repair the amp.

Concerning my Chartwell LS3/5A's:

I have made a couple clones of these lovely 44 year old speakers, because i love them so much. but my originals have lost the tweeter output. I tested the tweeter and all is good. This particularul 15ohm Xover has a history of one of the resistors getting too hot and indeed, a visual shows some good darkening of the PCB as it rests just on top.
I swapped out the Xovers and all is good so how does one test a Xover without ruining the original from a value perspective? AND, without disconnecting a single leg of any passive component? any secrets?

P.S. I have yet to measure the difference in ohms between both Xovers from outside the cab but i imagine they wont be the same.
Thanks

I’m working on a marts 30,000 but I have to get the output MOSFETs V1

I'm trying to get the full use it out of my Quad 44 and uses the mains connections in the back. I recently bought a pair of IEC adapters (A036 IEC 320 c14 to nema 5-15r) but I can't get them to fit on. Did anyone else experience this issue?

This new platform format hangs on me.....this message keeps appearing "oop´s We ran into some problem."..as my recent post to 6A3summer got completely mashed up. I get multiply reply windows which is annoying, and it isn´t a sticky keyboard.

Hey all - I'm wondering if anyone can help me find a replacement to this transistor please. If this isn't the right subforum to post this, please let me know. Thanks!

I'm trying to develop my repair skills, and am doing some repair work on an 80s integrated amp; this transistor has tested faulty, and the service manual says it's a 2SK105H. This is apparently obsolete, can anyone tell me what a modern equivalent would be please? Any help appreciated!!😀

Hi all!

After reading this forum and playing a guitar for a few months, I think I know a bit better what I want in terms of simple home studio of sorts. I'm asking for a sanity check and advice. I am looking for an inexpensive and efficient set of equipment - I am not opposed to spending more if it goes anywhere I understand but generally I want to stay lean.

I am mainly playing guitar (strat) by myself or with my daughter on bass (or she plays by herself). We also have an acoustic with a piezo pickup, a son/brother, who occasionally plays electric piano with us, and we will add a mic. All this in a living room.

• I want to have instruments feeding into some pedals, then a mixer, which goes to the monitors.
  
  
• We want to record/layer too, so it makes sense to have a mixer with a computer interface.
  • But I do not want to be tied to a computer and to have to power it up every time I want to play a couple of chords, so the mixer and monitors should work without the computer too.
  • It would be convenient to also be able to save tracks and layer on the console, without the computer - but perhaps this is too much to ask from an inexpensive mixer: to be a mixer, interface, and а tracker (?) all in one. Or is it?
    .
• UPDATE: following the suggestions in the thread, I found another candidate. So, currently choosing between A&H ZEDi-10FX ($300) and Behringer XENYX X1204USB ($209).
• UPDATE 2: I chose in favor of A&H because both people here in the thread and reviewers on amazon raised reliability issues in the Behringer unit.
  
  ORIGINAL TEXT: I found this mixer, which seems to hit most points: Allen & Heath ZEDi 10FX. It has 2 hi-impedance inputs, two more "mic" inputs, and some additional line/stereo/usb inputs. It is $300 on Amazon - not exactly cheap but acceptable if nothing reasonable is available cheaper. There are some cheaper mixers like PYLE PMXU 83BT but they seem weird: questionable quality and no hi-Z inputs, just regular "mic". But they are twice cheaper.
  
  
• I plan to hook up the monitor output to a SS TPA3116 2.1 board, which I power with 24VDC.
  
  
• I am not sure what to use for the monitors. I have ELAC bookshelf speakers (DB-52), and an ELAC powered subwoofer SUB-1010 but perhaps they are too delicate? This calculation following @Gnobuddy 's explanations suggest that they should be fine but I am not entirely sure.
  • If these are no good, what could cheap alternatives be?
  • There is an option to use the now-famous Logitech Z-623 but this is a separate can of worms. 🙂
    .
• The computer setup is less important at this point - but I would like to use a Linux-based DAW if possible since this is the only OS I have in the house.

So... asking for advice on the above. Does it make sense? Are there any better candidates for the mixer/interface?

Thanks!

P.S. Oh, yeah, this is the full list of what I have and use now:

• A Squire strat with the bundled cheap amp, and this fuzz pedal
• A squire PJ bass, and this multipedal for it (preamp, compressor, fuzz, octave, XLR out, effect loop)
• A cheap acoustic with a piezo under-bridge pickup, and this multipedal for it (delay, reverb, preamp, chorus, XLR out)

UPDATE 3 (2023-09-13):
I've now acquired all I had in mind, huge thanks to the advice in this thread. Here's the full list of what I have (also see pictures):

• Allen & Heath Zedi-10FX mixer (with USB 4-channel interface)
• Simple Frontman 10 amplifier, came bundled with the Squier strat
• Using the guitar amp from the above + old Yamaha 8" subwoofer wired together as a monitor for live jamming at home (short-term, will upgrade)
• Sonicake bass multipedal, acoustic multipedal, fuzz; Flamma FS06 digital modeling preamp
• Squier PJ bass, two Squier single-coil strats (hardtail and tremolo), simple acoustic guitar (Johnson)
• SM57 mic (yet to be tried)

Guitars go into some combination of the pedals -> to the mixer -> guitar amp+Yamaha sub

-------------------------
Related threads:

• https://www.diyaudio.com/community/threads/ultimate-audio-interface-for-home-studio-workshop.396928/
• https://www.diyaudio.com/community/threads/instruments-amp-y4-trio.383281/

I wanted to brag about this little thing I've done: I have this inexpensive Squier strat with hardtail bridge and top-mounted strings. I use pretty soft strings (Gilmour GHS), and the bridge saddles buzzed no matter how I tried to adjust them. So I drilled some holes, installed some ferrules, and now the strings are through-body, and nothing buzzes anymore.

It would be completely trivial except I did not have access to a drill press, so I did it all with a handheld power drill. It took some head-scratching to make the holes line up but I am pretty happy with the result.

I knew next to nothing about the electric guitars, so at first I thought I came up with an original idea - to put the strings through! 🙄 (My original plan was to just drill holes under the bridge, not all the way through, just to make room for the string ends, unscrew the bridge, thread the strings, and put the bridge back - that of course would make it a PITA to change the strings). But quick googling revealed that there is nothing new under the Sun.

The shiny coat does not lend itself to taking clear pictures very well but you can sort of see.

I'm building a pair of two-way Bluetooth speakers using Dayton ND65-8s and ND16FA-6s.

Below is my first attempt at designing a crossover in Vituix. Thoughts?

I purchased a Sony STR-D311 stereo it turns on won’t pickup radio stations and all I get is white noise?

Gents, let's discuss the linearity of output transistors, mainly bjt, for power buffer.
Background: I built many amps, and sure can be very happy with quite a few, but recently started experimenting with just buffers. Why? I do not need much power, i have plenty of preamps, and buffers sound much better to me after all.
Maybe its a lack of global negative feedback or something else.
Not interested in starting any flame war about putting shades on mona lisa, creating effect box, or insulting the artist. Fed up with that kind of bs.

I created two fully finished buffers based on c5200/a1943, one based on one output pair, one on three output pairs.
Now i want to experiment with other power bjt for outputs.
I got c3263/a1294.
I got w1302/w3281.
I got w0281/w0302. (I typed it incorrectly)
I hope i typed it correctly. (turns out I did not)
Which of these would be most suitable/linear?

https://www.diyaudio.com/community/threads/direction-of-diodes-in-an-amplifier.379908/page-3

Hello, I have a Pascal s-pro2 but there is an IC that blew, i can't read what is on top of the IC. Could somebody send a picture of say which IC that this is?

Hello, I found this design of Amp based on TDA1562, do you think its okay for home listening? Thanks for response 🙂
Or do you have other sugestions?

Hi all!

Although I'm a long time lurker around the forum, I'm still a newbie and don't have the knowledge to actually provide helpful inputs to anyone...
Still the forum has already helped me find valuable information in various subjects.

This time I'm looking for advise with a problem I have with the bass driver of a Tannoy Mercury m2 speaker

What happens is that the driver stutters intermittently, as if the connection is interrupted.
I've already resoldered the wires that go to the terminals, to no avail...

Is there anything else I can check, or is the driver blown?

Thanks in advance for your help!

Cheers!

one of my 121b's is rolling off the high end starting at 6k at 6bd per octave. any ideas what i should be looking for?
thanx,

Look on the picture for company,typ and series of caps.

I saw an interestingly built subwoofer and I'm wondering if it's a design that's familiar to anyone. It measures 17" tall, 12" wide, and 4" deep with no visible driver. There are 3 ports on the narrow 4" side and one port on the back under the plate amp. The amp looks like a Rythmik Audio A370-SE. Photos attached

I’m doing research for a possible build but there is no information on this outside of subwoofer use. I’m wondering why no one inverts one of two woofers in their 3way speaker? I’ll attach a rough sketch.

I can see a huge potential drawback being mechanical noise. The only quiet woofer I’ve used is the Acoustic Elegance TD15h.

Another drawback in this drawing is the bottom woofer is not time aligned, although that may be a nonissue in a 3.5 way design?

Is the reduced 2nd harmonic distortion worth it if mechanical noise can be overcome?

Hello all,

I know that is it surely a common title of topic, but I'm working on my new amplifier, and I want to add a DC protection on the output.
I want to manage the output relay with an ESP32 (all function are managed by him). So, "out" will be link to the ESP32.
I seen a schematic from Elektor (July 2012, page 62) interesting, and I simulated on Spice :





All seems work fine, but I want to ask to the diyaudio Engineer here for know if something seems wrong or not 🙂

Thx in advance !

Not a matched as such but identical other than in their looks ( one has tape over the contacts and the other doesn’t)
£50 + p&p

Sold

Just a quick impulsive question:
I've had very good results using local "Schade" (plate to plate) feedback in (SE and PP) amps with pentode drivers and pentode output tubes.
I ordered some output pentodes with very nice triode connection curves.
Now I'm wondering if triode connected outputs would work as well as pentode connection in this configuration.
Of course I will try it, but they aren't even paid yet, so that's for later. Meanwhile someone might have experience or an opinion.

Cheers!

What will you do when you find your recently successfully built DIY speakers have a lot of cabinet talk (cabinet resonance) in spite of the fact that you have already applied a lot of bracing?

Could it be compensated by tweaking the crossover network? Let’s say if you heard a cabinet talk, then you suddenly measured FR and found peaks at some region, e.g., 400 Hz. Can the problem be fixed by introducing a gap in that crossover region, e.g., about 300–500 Hz?

Or are there any more proper or correct methods of eliminating the cabinet resonance?

https://www.cultofmac.com/830180/is-the-world-ready-for-vacuum-tube-wireless-headphones/



dave

Hey all

After some bad luck with a faulty MiniDSP blowing out one of my drivers, I've decided I'm going to rebuild my active horn speakers with Fusion Amps - either a FA123 or a FA253 as it's the second time the MiniDSP has failed for some unknown reason.

I have some high sensitivity drivers - 108db, 111db and 98.5db, and with my current setup there's some very slight audible hiss from my listening position.

I wanted to know how the hiss is from the FusionAmps before I pull the plug. The SNR looks a lot better than the amps I'm currently using to drive them and I was hoping to get away without running 4 L pads for both midranges and tweeters which will keep the cabinet looking a lot better.

Any advice or feedback is greatly appreciated.

Hello friends, I have come into possession of a fantastic Aleph L rev.1.2 Pass. I've read that many owners change the potentiometer for something better. If you want to do this upgrade, which potentiometer do you recommend? Thank you

I have 2 integrated amplifiers, an electronic crossover and a selector. I'm going to establish a bi-amplification system. But, I'd like to have a bypass path for use with speaker set B in full-range operation.

I'd like to know will this diagram below work?

Bi-amplification mode:
The signal goes out from pre-out channel of integrated amp 1 to Tape 1 in of the selector, then it goes out from Tape 1 out to the input of electronic crossover. HF goes to main-in of integrated amp 2. And LF goes from electronic crossover to Tape 2 in of selector and pass to main-in channel of integrated amp 1.

Full-range mode:
The signal goes out from pre-out channel of integrated amp 1 to Tape 1 in of the selector. Rotating the knob of selector to "Tape 1 to Tape 2" position, the signal goes to Tape 2 out instead, and heading to main-in of integrated 1.

Note: The selector is part of Sansui AU-D11 II which was broken, so I only use its mechanical selector.

Hello, brand new here so please bare with me.

I have searched for this information on the The Unofficial LS3/5a Support Site.

Are there any new drivers being produced that have close specs to the currently out of production KEF B110 and T27?


If I was to buy a kit would I be able to use drop in replacements? Hard to believe some other manufacturer has not cloned these.

I am going to build a module around 3255 class d and need SMPS 45V. Where do you buy this?

Hi All,

I have a couple of Athena ASP 4000 Subs, one of which has just died, I'm looking at options to get back up and running as the woofer and box is still in mint condition, that and a replacement sub would set me back more than i'm willing to spend at them moment.

Essentially the options i'm looking at are to order another plate amplifier such as this one
https://www.wagneronline.com.au/sub...audio-speakers-pa/spa100-d-102862/1008470/pd/

Or looking to order a amplifier that has the capacity to power it as a passive sub with enough head room to do the second if it should ever fail.

https://djcity.com.au/product/fento...00w-digital-amplifier-with-bluetooth/#reviews

I did consider car amps and smaller units from amazon like the Fosi audio amps however the power supply required becomes a bit of a pain with extra unnecessary work.

The subwoofer pre out from the Yamaha amp is 1V/1.2 k-ohms, crossover is set in the amp.

Would either of the above work, has anyone got any other suggestions?

Thanks all for the input

I’m looking for a linear power supply for an ACA. Or even better, a single power supply(or 2 in one chassis) for a pair of ACA’s. Several on aliexpress, but none that are 60w/5a like the switching adapter that came with them.

I’m not entirely interested in building one as the parts seem to cost as much or more as a completed unit. Any suggestions on sizing or specific units would be appreciated. Thank you.

Hi again. I've been interested in designing a version of my first amplifier using LSK170/LSJ74 in the voltage gain stage and Exicon lateral MOSFETS in the output section. I spent some time in a simulator and came up the attached topology as a rough target. As it turns out, it was nearly identical to the ACA Mini, oh well. I'll try to spend some time today on a breadboard and figure out some component values.

I used their DFM Gerber viewer recently and it's pretty useful for checking PCB design before sending it to the fab. Their DFM report is very straightforward, pointing out the errors and making suggestions. Save time and money.

Anyway, I wanted to try their SMT service because they are offering free PCBA for 5pcs. Does anyone have any experience with them?

For those of you not familiar with their company, here's the link to NextPCB website:
https://www.nextpcb.com/

Selling the following in singles or pairs. All are in new condition and are listed at very discounted prices:

18Sound ND1480A New One Unit $160: https://www.ebay.com/itm/276040194193
18Sound 12W500 New One Unit $50: https://www.ebay.com/itm/276040191831
B&C DCM50 New One Unit $280: https://www.ebay.com/itm/276035745986
Mark Audio MAOP11 New Pair $300: https://www.ebay.com/itm/276040193770
Visaton AL200 New One Unit $70: https://www.ebay.com/itm/276041181929
TAD TD4001 Mint Pair: https://www.ebay.com/itm/276041181088

The subject line says it all. It would be sealed. What would be the Q of such a box? I’d line it with 10mm thick felt. A planar tweeter would sit on top.

Is this spec sheet correct? It shows the bottom secondary at 220V. What would that be used for?

https://www.antekinc.com/an-3222-300va-22v-transformer/

I have two vintage 1200VA transformers rated for 240V primary and outputting two secondary windings at 58V ea. Fully refurbished. These things are brutal and weigh so much I haven't been able to put them on any scales I have (30kg plus). They came out of a early 1970s designed mono amp rated for (from memory) 650W RMS into 8ohm. They were swapped out for toroidal transformers because the roadies used to complain about them. Probable interest would be for a DIYer to build into an amp design that was not going to get moved much or a serious bench power supply.

Looking to sell them. $250 plus freight. Is there any interest for these beasts?

Anybody looking for this part 958 parts are in stock

I have two class D amps, both using the TDA7297 chip. One is a Chinese pre-made board from eBay with 50k dual pot.
Pre-made circuit

The other I've made following the details listed on the electro-dan website, which is a similar circuit.

Electro-Dan website
Electro-Dan circuit

I need to be able to mount the dual pot within a radio, so the pot can't be mounted on the PCB due to available space.

Testing the pre-made board with pot mounted on the board, and being powered by a 12v CCTV PSU, generates no noise and is pretty good clean output.

However, when desoldering the 50k pot and extending using cat5 wire, it creates a clicking noise and faint hum. Low and high ends of the pot have no noise, just everything in-between is noise.

I've tested with a new 47k dual pot and get the same noise issues. This is marginally reduced when touching the metal back of the tda7297 with my finger.

The home-built circuit (I'll upload a circuit diagram later) has the same noise issue when using the 47k log pot or a 10k linear pot (both extended using the cat5 wire).

I have un-twisted the cat5 pairs and shortened the wire, which hasn't made that much of a difference.

Do I need to use shielded wire to the pot?

Any other recommendations please?

I have been thinking about creating an All SMD component Class D amplifier. The purpose would be to keep a totally clean back side of the PCB, so that mounting the amp to a heatsink or an aluminum plate would be as easy as just using a foam heatsink spacer in the full size of the PCB, with maybe a single or 2 screws as a safety measure if the adhesive should somehow slip over time.

Only starting

The size is limited to 100 x 55 mm as I want to use a small 100 x 60 x 10 mm heatsink from Aliexpress, at least for some builds

The attached picture shows the very first version where the schematic is not finished yet, but where the larger main components have been placed. As can be seen, there will not be room to spare, and it's not even for sure there will be room enough. First picture is with D2PAC Fets, but it would save a lot of space to find a suitable type in a Super SO8 PQFN 5x6 package ... see second picture. The voltage must be limited for this amp to something like max +-55V, as the coil will only be able to handle less than 10A also to find suitable MosFets I'm sure I will have to use 150V versions and not 200V as I usually do.

PCB will be 4 layers and will be made at JLCPCB. I will try to use basic components from JLCPCB as much as possible to limit the cost, as it cost 3 USD for every extended component type you use.

The MosFet footprints will be perforated by a number of vias which will act as a thermal conductor from the topside of the PCB to the bottom side, where the heatsink will be placed.


Now I'm trying to find suitable fets, and there actually seem to be quite some ..... seems the development is racing on for mosfets in small packages, but has almost halted for TO220 types!!!

Take a look at either BSC360N15NS3 or NTMFS034N15MC, 150V, +30A, around 30 mOhm, super fast including diode, and easy to drive with Ciss less than 1 nF ....... I'm thinking what's the catch here??? .... and why bother with GaN fets????

https://www.mouser.dk/datasheet/2/196/BSC360N15NS3_Rev2.0-75853.pdf
https://www.mouser.dk/datasheet/2/308/NTMFS034N15MC_D-2037032.pdf

Hello,

Does anybody know if there is a way to recover the filter design from a Hypex FA123 amp? I lost the Filter design file...

Thanks!

Bernard

I have attached a picture of 2 different port responses in 2 different speakers. One response has a much steeper "low pass" response. One is less steep and is only down about 10db at 100HZ. Is there a better way to control this? Can anyone shed some light on why they would be so different? Both ports are 2" in diameter and about the same length. Both cabinets are about 1.2 cubic feet internal volume. One box has 2x Scanspeak 5.5" woofers and the other box has a Purifi 6.5" woofer.
Thanks!

Parts recycled.

SOLD.....(PRICE DROP) Open box. 230.00 for the pair plus shipping and PayPal Friends and family or personal check.
Thanks OB

Pascal Audo S-PRO2 class D power amp module OEM version IS NO LONGER ON SALE

I've updated the original SSDCB to offer the following benefits on the new iSSDCB

1. Greatly simplified wiring required only on the mains supply side of the transformer
2. Double the full AC mains load capability of the original SSDCB – 4.6A vs. 2.3A
3. Allows use of attractive anti-vandal power control switches – max required switch current rating is 30mA DC
4. Very low standby power draw of c. 0.2W
5. In-rush current limiting of 10A for 1 second
6. Small compact, easy to assemble PCB

Here is the link to the project download page on Hifisonix.com https://hifisonix.com/projects/imroved-soft-start-dc-blocker-aka-issdcb/

If you have any questions, I'll be happy to answer.

Back in the 1980s, many commercial speakers had attenuators for tweeters; some also had attenuators for midranges. There were many attenuation levels. One of the interesting points is +/- 1.5 dB. I’ve read somewhere that human ears begin to hear a difference in sound level at about +/- 3 dB. Yet, why do many manufacturers put +/- 1.5 dB on their attenuators? Or, actually, the +/-3 dB was discovered after the 1980s era? Anyone who has experience with the 80s speakers or has knowledge about this, could you please confirm the fact about +/- 1.5 dB or +/- 3 dB?

The fully-differential OPA1637 (and it's predecessor OPA1632) have an enable (shutdown) pin.
I have an app where I would like to use that pin for a mute function.
Does anyone know if there is an output transient when switching from enabled to disabled or vice versa?

Jan

SOLD

I bought them for a project that won't be done and they doesn't fit my needs to replace other tweeters due to the 120mm face plate.
Price per unit now is 600€ and there is a very few availability due to berillyum diaphragm supply problems at Scan Speak.
Like new. Measured and tested in bafle and then stored.


I would consider swapping for SBacoustics Beryllium tweeters: Satori TW29BN (or B) tweeters or even Scan Speak illuminator D3004/664000

I'm thinking of a new DIY build and like the look of the neurochrome modulus-86 and the reward of building it.

However for a similar price and minor assembly (less interesting to me) the Hypex Niali 500 as well as purifi have good reviews and performance.

Is this just a class AB vs Class D taste question, would I even hear a difference at this level and is there a shelf life/longevity benefit over AB vs D.

Its for a small listening space and easy to drive speakers

Thanks in advance.