Hi. I have a couple of pairs of the gorgeous TKD 50k mono potentiometers (Volume controls) for sale. These were used in a volume control shoot-out in a multi channel system. They are in near mint condition. The input, output and ground connections have been carefully desoldered and cleaned. I would like $85/ pair, shipping in USA included.

Hi all, quick question. My crossovers have 2 pots each to adjust highs and mids. One of the mids pot is completely shot and the other one reads funky. Tweeter pots seem OK but they're 42 years old.

According to schematics, all pots are 5 ohm 5 watt:



But in real life, they're clearly different. Folks say the mids pots are 15 watt and the tweeters 5 watt, and that looks plausible:



My first thought was to just replace the old pots... but audio grade 5 ohm 15 watt pots only appear to exist in Australia

So now I'm considering replacing them with fixed resistors, since their utility is debatable to begin with.

I tested them (out of circuit):

• Tweeter pots measure 2.5 ohm at midpoint and 5 ohm all the way down, so that's all good per specs
• The one mid pot that sort of still works measures 3.4 ohm halfway, and 5.7 ohms all the way down. The other mid pot is too far gone to measure anything.

Now for my questions:
a. That mid pot's 3.4 ohm halfway to 5 ohm read doesn't match a known taper. Is it fair to assume it was linear when new, and it just drifted over the decades?
b. I want a "flat" response, so I'm thinking 2.5 ohm fixed resistors (assuming those mids pots are in fact linear). As far as power rating, it's tough to find 5 and 15 watts in the same series but Dayton makes 2.4 watt, 1% wirewound rated 10 watt and 20 watt, so I'm leaning that way and it won't break the bank. Still, it would mean a significant increase in power rating over stock
c. I've done a bunch of reading about whether increasing resistors' power rating can affect sound quality, and the consensus seems to be that it won't make it worse and it might even make it a little better. Do you guys concur?
d. Now we're splitting hairs, but I gotta ask: my new fixed resistors will probably have much lower inductance than the pots they replace. Does that mean anything in terms of sound quality?

Thanks!

According to the seller only tray pack has 'Japan' marking on 2sc5200/1943 transistors & there is no mention of 'Japan' in the strip pack(see attachment). I believe these are 100% authentic, what do you think? 🙂
Best Regards!

Edit:- These aren't original but good quality chinese copies. My apology to everyone.

In 2017, I built this amplifier for my brother's audio system. It is a single common grounded collector amplifier based on RMX series of QSC.

Supplied with +/-80V, I added five pairs of transistors for output stage. It is very stable once the bias adjustment is set properly. The input opamp is very important to be good quality and check +/-15V rail supply to be as simetrical as possible. I wanted to keep the same subsonic filter to cut off frequencies under 30Hz and 50Hz.

The sound is very good however I was designing a PCB with smaller size. Thanks

Hi just wondering if its possible to replace jfets and mosfets with bipolars which
i have lots.
just something to try while waiting for parts.

Hello. I’m working on my TX 870 and having a few issues. The left channel dropped out and the main fuse blew. I found a cracked bridge rectifier and it was toast. Replaced it along with all the outputs on the left channel. Found some bad transistors on the main board and also replaced the drivers. For some reason I’m getting full rail voltage at the VCT test pin. This won’t allow the protection circuit to close the relays. It should be in the millivolt range. The right channel is fine. DBT goes bright as the main power relay closes and then opens and the DBT goes dim. Constant cycle. I’ve got the service manual and have replaced the emitter resistors, and several other bad components that tested bad. Any ideas ? The output transistors are fine. No shorts. Thanks in advance. The only other thing I replaced were the 2 caps in the protect circuit.

hi forum
i've just watched a video on the steve guttenberg youtube channel featuring a gentleman called joe who is into horn speakers, he referenced this forum in the video.(the video is from 5 years ago)
in the video he briefly touched on the design of his subwoofers, which use two speakers working opposite to each other and facing in opposite directions. i'm hoping that this subject has been discussed already and that someone could point me to the correct thread, or even plans and theory for this subwoofer.
this is the video -- Login to view embedded media
any info is appreciated
gaz

Hey everyone, brand new member here who will probably leech more information than contribute given my complete lack of electrical/acoustic intellect (drummer, go figure). In fact, I never thought I'd be reading much less typing messages to this group since I've always been an OOTB audiophile musician gear-collecting type, albeit single-driver-curious, but that seems to have changed last week:

1. Finds pair of Fostex fe206e-loaded cabinets for $100 on fb marketplace and says screw it why not
2. Plugs them into garage "tester" setup (Arcam receiver, Meridian Explorer portable dac), sounds like crap
3. Removes the reflex port to discover there's some sort of crossover network thing, bypasses it, listens again, ok now we're going somewhere interesting
4. Swaps them into the Rogers LS3/5A livingroom setup (Naim entry-level separates, Bel Canto 1.5 dac), and despite flaws, there's something alluring that bears more exploration
5. Swaps them into "reference" DeVore Gibbon Super 8 system (Naim Supernait 3 integrated w/ HiCap DR, Rose RS150b streamer/dac), hasn't left chair for 5 hours (other than to make dozens of adjustments to speaker/listening position). Oh, and signs up for diyAudio account 😉

Wow. As absurdly, unfathomably finnicky as these things are about placement and amplification/sources, there is a magical palpability and image that, until now, I've only heard others talk about with their setups, or have only heard myself on (some but not all) six-figure setups at shows.

So, this is all to say I forsee myself spending hundreds of hours scouring this forum for tweaks and advice, of which there appears to be no shortage of, and will thank you all in advance for your volumes of reference for this strange and beautiful new world. Well, not always beautiful since function>form is why we're all here 🙂

Oh, and speaking of which, whoever made my cabinets actually did an impressive job making their fit and finish as furniture-grade as possible. Beveled edges, invisible joins, nice (cracking, will need restoration) veneer finish, black platforms...real classy work. Would love any information anyone may have on them (and of course, modding pointers to help me navigate the sea of information that is this forum)!

When designing a sub should I aim to get the SPL graph to match the equal loudness curve? That's what I was doing initially while trying to design something useful for a cheap driver. I didn't have much hopes for this driver, but found a design that should work well. It matches the equal loudness graph from 27-80Hz for 60dB listening. I wanted to compare its simulated performance to something, and having looked up a 15" Hsu sub, they show a mostly flat graph that slopes down as the frequency decreases. They should know what sounds good, so am I doing it wrong?

Do you think we have come to a state where we could build a field recorder without a gain knob. I am pondering if we have the noise levels and dynamic headroom in both analog and digital domains that we could just set a gain and live with it for any recording really.

Prerequisite is perhaps mic sensitivity and noise figures... I'm thinking really serious state of the art recording like organ in church, closed mic guitar amplified small jazz club etc. So noise level in the chain should just beat any normal recording space by a safe margin (3-6 dB?) but i.e. need not meet the requirement to record mosquito farts in outer space from 100 meters.

Is it feasible? What would it take do you believe? Do the gear exist today. DIY of course ;-)

It would be so nice not have to consider setting the level knobs position. Are they equal? Will it clip? Get the potentiometer out of the signal path... etc... just set up the mics, power on the gear and hit Record.

My hope is that now we have such low noise mic amps and high dynamic/resolution ADC that we can just create a recoding unit and it will take on anything really. Maybe a high and low switch somewhere 🙂 that shifts the whole thing 18 dB in the digital domain?

Could someone elaborate on the gain and noise structure?

Mic in -> 24/96. (44,1)

What say thee?

//

I have simple horn loaded, rear vented cabinet model.
Why frequency reponse in Akabak and Hornresp differs?
I'm particularly interested in falling character of the Akabak response and in dB level offset.

I exported the akabak script from the Hornresp and manually rechecked all values in the LEM model.
The model parameters are identical in both softwares.

See models setup in screenshots.

For reference this is the hornresp generated Akabak script.

It appears that this is no longer available from Vacuum State. I tried to order it from their site and the payment gateway is not working. There was no response to an email I sent to their listed contact.

I'm planning to build an RTP3C line stage and I'm sure this book would be really helpful. Does anyone have a copy they'd need willing to sell?

I’d like to put together something like the An-e speakers. Does anyone here have experience with this? Cabinet build plans?

I found some threads here from google from a couple of decades ago. This is how I came to know of this site. It does not appear that audio note currently sells kits.
All help would be greatly appreciated. I don’t need it to be an exact clone. Just as close as possible.

I’d also like to know if anyone might be local to NYC who could lend a hand, as I am disabled.
Seas a24re4 and Morel Cat378 seem to be popular for Audio Note-inspired builds.
I was also looking at Supravox 215-2000EXC and the Eminence Beta-8A.

I’ve been into hifi for a long time, but am completely new to DIY speakers. I don’t know what goes into designing a crossover, speaker, etc. I only know what I like to listen to. I’ve heard a few audio note speakers over the years and they have a sound I can listen to all day. The models I heard, at least.
I just found a couple of cloned audio note speaker youtube videos by chance and I thought it looked interesting. As did the thousands in potential savings.
Unfortunately, I can’t put it together myself, due to my physical limitations, but it would be nice to be involved in the project.

Thank you.

The search for previous topics about this yielded nil results...

Specifications of tubes were published in books, along with examples how to deploy them.
Attached is an example of the ECC83 / 12AX7 transconductance and output characteristics (scaled & merged) and shows a maximum Ia of almost 6mA (@250V).
But how accurate are these specifications? What amount of variation ('spread') of values can be expected?
In %'s, both small signal and larger types (eg PL519).

I've got an interesting one that I've never seen before, I'm hoping someone would shed some light on why this was done. This is an audio research vt60. It's had some mods done, and the schematic that's floating around is about half incorrect, but it seems like someone modded it to use this mosfet on the cathodes of the driver tubes, with what I think is the gate tied to ground, as I understand, this just makes it a fancy diode?

Someone painted over the markings on the fets so I've been having trouble figuring out the part number of it, I need to pull it and check it, but I just wanted to ask, has anyone seen anything like this?

Excuse the crudity of the schematic, I'm trying to red marker all the changes on it.

Any tips? I've watched a couple of youtube videos. I dont have much experience soldering but it kind of looks like it would be good practice.

What plugs and cable do you recommend? I was thinking Neutrik plugs. Is there any point in going for something like Van Damme star quad cable or will that just makes the build a bit more tricky?

Hello, looking for a schematics of Aura Va150 (auv-150)
It's not very similar to VA50 or VA100 (they all probably have the same power amp schematic, but everything else is different)
I know it does exist, but I found exactly one mention of it on a french forum here
https://www.ls3-5a-forum.com/viewtopic.php?p=44515

But the link expired long time ago, and the forum is behind some type of donation to even start posting there.
So if anyone will read this from this forum or just happen to have this schematic it will be much appreciated.

I can trace the pcb but it has 2 layers, so need to desolder parts to do this and would like to avoid this as the pcb is already damaged by heat.

Hello,

I recently acquired a set of RCA SA-1000, 6550 push pull 100W mono blocks amplifier manufactured in 1960’
I wondered if anyone has its schematic?
The only schematic I found in DIYaudio forum was from a post in 2013 and it was very foggy.

I appreciate if anyone happen to have it and can share with me. Clear version please. Thanks!!!😊

A friend of mine built two Aleph 2 mono blocks for me about 17 years ago, long before I started doing any building myself. They were fine but run very, very hot (in hindsight the Modushop 4U 400mm cases are too small) and there was something not quite right when you compared them to my factory Aleph 3. I know, a 2 will sound different than a 3, but the 2s just don't sound as relaxed (for want of a better word) than the 3 or for that matter my diy F4s.
I knew some of the parts he used were not what I would choose today, so the cement block 1R and 0R47 resistors will be replaced by 5W metal films. The 220uF caps of unknown brand will also be replaced, but I am not sure yet what to use. I have 220uF Silmic IIs (25V and 35V) and Nichion Muse FG (25V) in my drawer and some Nichion Muse KZ (50V) and Nichion Muse ES bipolar (50V) on order. Any suggestions which to put where would be appreciated.

I also noted that in an old thread, the ZVP3310A was mentioned as a good replacement for the 9610s. http://www.diyaudio.com/forums/pass-labs/172987-zvp3310-good-choice-input-fet-aleph-30-a.html
It as an old thread, so I would be interested to hear if other people have since tried this and what their results were. I know they are not in stock at Mouser, Digikey or Farnell/Element14 but I think I bought about 25 ZVP3310A many years ago, so could hope to get a few matched pairs (if I can find them haha).

The power supply currently consists of:

• Talema TRT1000240 1kVA 230V primary 2 x 40V 12.5A secondaries
• Standard GBC type bridge rectifiers
• CLC :
  • 47000uF/63V F&T GM
  • Intertechnik aircoil 2.2mH 0R46 (1.4mm copper)
  • 47000uF/63V F&T GM

The first problem I noted was of course that in this configuration, the rails will be much higher than spec (according to psu designer about 51V with an 11mV ripple). As the mains voltage where I currently live is 240V, I can expect another 2V, giving me rails of just over 53V. I understand from the service manual that the circuit will adjust bias automatically, resulting in a lower bias, so I expect dissipation to remain 300W per monoblock.
What alarmed me is that according to psu designer, the ripple the first 47000uF cap will see is double the rating of the cap (max. 13.2A according to datasheet). Not good.
The amp has not seen that many hours (I have too many amplifiers 😎) but the first cap could be seriously aged by this maltreatment. How can I check the condition of the cap? If it is still OK, I assume swapping the hard driven first cap with the hardly stressed second one will prolong life?

Obviously, the ripple the first cap sees has to be significantly reduced. Ideally the rail voltage should be lowered as well (the circuit will automatically increase the bias to accomodate for this). Just adding capacitance does not seem the best solution.

I remembered something EUVL said about adding resistance in the psu (when I tried to get rid of hum in my Aleph H). I played around with psu designer and came up with the following simple solution: Convert the CLC design into RCLC by adding 0R75 resistance before the first cap. (N.B. I also tried LCRC using the same values, but psu designer showed excessive voltages experienced by the bridge rectifier and a higher ripple at the load).

According to psu designer, with the RCLC psu the first cap ripple is less than 50% what it was previously (now within datasheet spec) and the rail voltage drops to 45V (from 51V). The resultant load ripple (simulated as 17R in CLC and 13R is RCLC to give about 150W dissipation per rail, to compensate for the circuit automatically adjusting the bias to keep dissipation constant) hardly changes (I surmise it is probably more dependent on the size of L and C2).

I assume this solution will add quite a bit of heat (psu designer calculates 6A RMS at 4V5 RMS through the 0R75 resistor, so about 54W per mono block). I will have to add fans for these Aleph 2s anyway, and especiially to survive the extra heat. I have some old PC fans of various sizes but am unsure if placement in the enclosure will give enough relief. Has anyone tried this?

Having had plenty of trouble with radiated noise recently while testing a newly built pumpkin in my shed, I am wondering if the placement of the coils in my amps could be improved upon. Ideally I would move the transformer and coils to another box (perhaps even try a regulated psu) but a 4 box stereo amplifer really is a bit too much. I have attached a photo of the current layout (don't take any notice of the old soft start to the right of the bottom coil; it has since been replaced by an NTC).

Will a steel cover over the transformer (if I can find one that big) and/or coils (assuming I have enough room to do this) make a big difference?
Any suggestions are welcome!

Building a CSS audio's 3TD-X and plan on building out some more speakers after getting my feet wet a bit.

Planning on building a center and on wall next!

Hallo,
I have already shown my combination of ribbon and HiVi 7500 in the midrange dome thread, but I am not satisfied with the cheap 10” bass, I am thinking about how I should design the bass section.

The HiVi 7500 will later be separated passive at 500-800 Hz with 12 Db.

I am considering one 8“ or two 6" drivers.
The loudspeaker should later also work directly on the wall.
That's the plan...
A closed volume with a high-pass filter (condenser 900-1700uF).
If the bass tends to boom when placed on the wall, the high-pass filter can be bypassed.



Simulation 8" SB23NRXS45-8 with and without high-pass filter.


Simulation 2x6" SB17NBAC35-8

Without bass reflex the maximum volume is limited but would be enough for me.
I like the slight drop in the bass range, which helps to avoid booming.



My questions:
Are two parallel 6” speakers too loud for the HiVi 7500?
What do you think about the arrangement of two 6" bass drivers above and below the tweeter-midrange unit (distance center to center 400mm)?


If you still have questions or suggestions, please!

Hello everyone.
I'm working on my first class DYI hifi amp.
A "simple" assembly of pre-assembled boards ...let's say a school prototype with no pretensions other than to sound decent. The result isn't top, but I learned many lessons that I hope to apply at best way in V2.
However, there is a very annoying problem for which I would like the valuable opinion: the PSU, I know it is not the best, has two 12v auxiliary outputs. I needed one to power the LEDs on the front panel. Well, if I connect even a single LED to one of the outputs, a constant buzz is generated regardless of the volume setting. With the 12v contacts empty, nothing. I also noticed that if I touch one of the two contacts (under load) with a multimeter tip, the buzz fades out by half or so. The case is made out of wood with no grounding.
Can you help me remove the problem?

As per title, standmount cabinets for fostex 206e
Must be extremely well made, unfinished is fine as I can do that.
Or suggestions on where I could find some.
I might be able to build some, so plans also useful.
I do have the original kirishima cabinets for them that I would happily swap, but you would have to come to me, as my car isn't big enough, they are huge and heavy!
Cheers
Graham.

Hi there,
a Happy New Year!
Is anyone able to help me with a repair manual for an a/d/s/ 250mx amp? If there is such a thing..
Is also the cookbook still around?
Cheers!

Also like learning of mods, practical tech issues, gear, solid state and circuits in general. I'm a BSEE and Comp Eng. MS, work as a Systems Engineer in software architecture, been a tinker/tech for years, doing fixes for myself and local musicians. Hope to connect and get some good info here.

I'm designing a combination HPF + boost/soft clipper for use with bass and electric guitar.

This is the general schematic:



Since I'll build straight to SMD, I want to minimise the chances of having issues with noise and/or oscillation.
U1/U2 will be an OPA1678, while U6/U8 (don't pay attention to the references) would be an NJM5532. They will both feature 0.1u MLCC caps to ground at the V+ pin, of course.
Power supply will be 9->24V.

The main points of contention are:

• would it make sense to add in a resistor (like, 1kohm) in the feedback path of the buffers (U1/U8)? I've read that sometimes this makes the design more resilient.
• what about input resistors or input capacitance?
• I'm assuming that with the aforementioned opamps, there wouldn't be any issues with phase reversal, right? Were I to use different opamps (say, a 4580 or a 4558, or a TL072) is there a way to ensure that phase reversal would never happen? I remember reading that adding a 3.9k resistor at the positive input of a non-inverting opamp sort of cures the problem.
• are there any areas that could do with some optimisation, or things I may have overlooked?

Thanks.

sell a pair of Azura AH1100 1 inch le cleach profile horn . look at these beauties
asking 250€ ship only to EU

thanks .

I am selling my (private) stash of AmpOhm capacitors. These were bought in 2010 and never used. They are not made anymore.

• 4 Pcs. PF-XAL-AL, Paper in Oil Aluminium Foil, 10uF 300VDC, €60,-- each
• 4 Pcs. PF-XAL-AL, Paper in Oil Aluminium Foil, 5,0uF 300VDC, €40,-- each
• 6 Pcs. FE-XAL-AL, Polyester Film Aluminium Foil, 6,8uF 630VDC, €60,-- each
• 2 Pcs. FE-XAL-AL, Polyester Film Aluminium Foil, 2,2uF 630VDC, €45,-- each

Small discount possible when buying all in one go.

Shipping costs available on request. I am located in the Netherlands.

hello
I have bought some years ago Bill Beard BB101 with right chanel Dead.
After testing the Toroidal transformer was in short.
Comparing with the left Chanel I Can "Rewind" the the shorted one.

In order to rebuild this Amp I need the Service Manual. I search during long time and no sucess.

Anyone can Help Me?

Regards

hello
I have bought some years ago Bill Beard BB101 with right chanel Dead.
After testing the Toroidal transformer was in short.
Comparing with the left Chanel I Can "Rewind" the the shorted one.

In order to rebuild this Amp I need the Service Manual. I search during long time and no sucess.

Anyone can Help Me?

Regards

Had a perfectly working f5m playing music then just stooped .blowing ac fuses, Found it was
left channell issue,.
Removed mosfets and jfets , found mosfets faulty , jfets tested as fine.
So replaced mosfets re installed the jefets new r6 and r7.
connected power and was slowly ajusting bias, going well then all of a sudden
smoke started coming from R5 which is the 22w 2watt resister included in the kit,
should i just replace R5 or do i have a problem with the jfets ,
thanks
Glenn Kaspar

Hi all.

I am in the process of designing a new 8 channel DAC/active XO/preamp for my active 4-way system and I want to add a 12V trigger out to remotely start the amplifiers, four Fosi Audio ZA3.

The DAC will have a 5V SMPS to power the standby/activeXO/MCU circuit (Raspberry Pi based) and a linear PSU that provides 5V for the DAC digital circuit and +12V/-12V for the output stage (a simple opamp based I/V circuit).

My concern here is how to provide 12V to the trigger out circuit, in special how to avoid introducing noise and how to avoid ground loops. My previous experiences with Fosi's trigger in was terrible. The port doesn't seem to be isolated from the main circuit so, if you connect a noisy device, the noise goes directly to the audio.

In my current design, I used the 12V line from the linear PSU (the same that powers the I/V stage) through optocouplers to ensure the complete isolation between the MCU circuit and te 12V circuit. My concern here is to introduce noise in the I/V stage, coming back from Fosi's trigger circuit.

Another option that I see would be to add a new tiny 12V PSU just for this circuit (a linear or a filtered SMPS as Fosi's trigger in will introduce noise into the system).

For the experienced electronic circuit designers here, would you please recommend the best approach? Maybe adding filter caps in the trigger circuit?

Dear Folks,

Looong time ago I developed some DI boxes and Guitar preamp stages with tubes. Mostly using nice russian NOS tubes, or brand new type from JJ.
Well, it´s winter and I need a new project beside fom hacking C-code and some "sand"-processors.
In my stock there are two nice 6N13S tubes, waiting to be used. 🙂
Any hints for a prooved schematic using this fine tubes to drive a standard 50Ohm Headphone ( Sennheiser HD558 )??

Best Regards
Karsten
Edit: Forgot that C in Cyrillic is an S 🙂

I have a broken Hypex NC400 with a SMPS600N400 power supply (that is fine). The output of the supply is 2x 65V, too high for the 3e audio amp board (3E AUDIO 260-2-29A PFFB Stereo amplifier). Is it possible to step down the voltage of the SMPS600N400 to say 48V while maintaining the max 650 watt? Or is this not a good idea anyway and can I better buy also a new power supply that is already 48V (like the micro audio SPMP-R2)?

I am in the process of changing the capacitors in my JPW GOLD speakers. The writing on the existing capacitors is buried in glue. Does anyone know the capacitance and voltage values please?

I showed some time ago GainWire mk4 balanced preamp, but there was no interest for balanced preamp, as it seems.

Now here is GainWire mk3 CFA preamp with very, very low distortion at all frequencies and output levels.
It could be used as level preamp or headphones preamp for low or high impedance headphones.

The gain was set to 12 dB (3.6 times).

If used as a line preamp distortions are as below:
THD1k at all practical levels is zero in simulation.
THD20k is below 1ppm at all practical levels, 0.14 ppm at 4Vef at the output.

If used with high impedance headphones distortion is very similar to the line preamp mode.

If used with low impedance headphones as Grado 32 ohm then distortion is as below:
THD1k is 1.05 ppm at 2Vef on the output.
THD20k is less then 4 ppm at 2Vef.
Grado headphones will give SPL of 99.8 dB at 1mW and that is 0.18Vef, 2Vef will produce 0.125W, more then enough.

I designed two types of PCB, for single channel with no power supply and for two channel with power supply(similar as GainWire mk2.
Damir

Link to the post what transistors should be matched.
https://www.diyaudio.com/community/...ery-low-distortion.296545/page-4#post-4844159

Link to the BOM.
GainWire mk3 CFA pre/phone amp with very low distortion - Page 7 - diyAudio

Matching.
https://www.diyaudio.com/community/...ery-low-distortion.296545/page-4#post-4848920

Thermal bonding of the BJTs, examle.
https://www.diyaudio.com/community/...ery-low-distortion.296545/page-5#post-4854722

For capacitance multipliers (Q27, Q28) better use BC337-40/327-40, less prone to quasi saturation.

Updates, some values changed. http://www.diyaudio.com/forums/soli...e-amp-very-low-distortion-12.html#post4861045

PCB error and how to rectified it :
silkscreen error:http://www.diyaudio.com/forums/soli...-phone-amp-low-distortion-12.html#post4861045
http://www.diyaudio.com/forums/soli...e-amp-very-low-distortion-20.html#post4912003

Modification to get better clipping behavior: http://www.diyaudio.com/forums/soli...-phone-amp-low-distortion-28.html#post5158715

How to correct layout error on the board layout ver. 1.3. Ther is one short connection. http://www.diyaudio.com/forums/solid-state/296545-gainwire-mk3-cfa-pre-phone-amp-low-distortion-
29.html#post5212455

BOM for PCB version 1.5
https://www.diyaudio.com/community/...ry-low-distortion.296545/page-20#post-7137481

I'm 48 years old steel factory worker from Finland. I always prefer to do things by my own hands, when I can reason it somehow (usually getting better or better suiting or unique product for the same price, or preferably even save some money). I have pretty modest set of tools and I don't understand electronics, but I get things done. I don't like to use too much time for thinking and hesitation, I just need get to work. With that said, I'm here because I would love to build my own Genelec 8020 "killers", but as cheaply as possible (for home theatre and music), and perhaps with a subwoofer. My wife loves how those white speakers look.

And then I would also love to have something between 8010-8020 as my "home studio" computer speakers.

Hi, sitting here thinking about what will happen to vintage audio equipment in the future, let's say 20 years from now? The reason for these thoughts is that I now have a complete system that I want to take with me far into the future, but what about parts in the future? Electrolytic capacitors, v.t. Displays, transistors, laser pickups, etc.. those of you who think the same, how do you future-proof your audio equipment? I'm thinking that having a similar set standing as a backup could be a solution, but need some tips and advice..

Hello,

I have RCA SE signal and need to send it to balanced input with TRS.
( never used balanced devices .... and need to keep the smoke in 🙂 with your help ... )

After some schematic / wiring search found attached wiring - I hope it is correct ?
( RCA RED --> TRS RED - it is OK for me - it is logical 🙂 ..... no questions here .... )

BUT why ? ...
1. RCA ground ( black ) is connected to TRS black ( negative ) and not connected to TRS Shield ? What is the 'logic' or explanation of this ?

Please, explain to me why we use Positive and Negative pins on TRS to send the signal into device ?

Thank you for your time and help,

Emil

Hello guys! I have an idea to build my own tape recorder (for home). I will use tape from cassettes only with a playback head for two channels (stereo). The output from the tape recorder is only for headphones (or for speakers). I need to find circuits for an amplifier (to get a relatively clean sound/color the sound and amplify it for comfortable listening) and good motors for pulling the tape. I am ready to consider ready-made solutions for this (in terms of ordering from Aliexpress and simply connecting them together inside the device).The tape pulling diagram is attached. Thanks.

Almost the best Pure DSD R2R DAC with no DAC chip just digital/analog filter, open sourced by puredsd.ru to go with hqplayer.

• Network based streamer, with NAA (Network Audio Adapter) embedded for hqplayer front end.
• HQPlayer preferred to upsample PCM/DSD to DSD256/512.
• DSD signal received by BBB single board computer is further isolated then reclocked.
• Transformer based output, outperforms Lundahl LL1684.
• NOS NXP 74AHCT595D (not newer NXP with X logo) as recommended by designer for best sound.
• 128 Tantalum Nitride Precision Thin Film Chip Resistors ($1 each) deployed on resistor boards.
• MSR860 Soft Recovery Rectifiers and low noise LT1963 regulators for off board first stage power supplies.
• Dual stages ultra low noise regulators for digital processing.

DSC2 DSD R2R DAC with hqplayer NAA embedded (BeagleBone Green running botic firmware).
Single end or balanced output with toggle switch at the back of PCB.
Three separate low-noise power suppliers built with Toroidal transformers, MSR860 rectifiers, Panasonic-FC capacitors and LT1963 regulators.
The BeagleBone board position can also accept Amanero combo384 or combo768 card.
Only DSD (DSD512 native mode preferred) encoded stream from hqplayer is accepted.

Asking USD 450 or AUD 695

Please complete payment within 3 business days via Paypal or bank transfer, I will ship this unit within 3 business days after the payment cleared.
Buyer pays for postage.
Or cash on pickup in Bulleen 3105 Australia.

Any idea why there are cracklings (echo like) when I use the mix console as external audio interface?
It worked once, then I tried to use usb piano keyboard and messed the driver and settings (to lower the latency)
Then I switched to the onboard audio and actually forgot about the problem..

Now I am trying to use the console like audio interface (just for listening online music) and cannot set it back.
Cant find specific behringer driver, the problem is both if I use 44.1 and 48k rate.

I'm currently doing some research on preamp concepts which basically resemble a balanced volume controller, if I may say so.

While doing so, I came across a design by Bruno Putzey which he lays out here: http://www.hypex.nl/docs/papers/The G Word.pdf (originally written for Linear Audio Linear Audio | your tech audio resource , Volume 5 came out in April 2013 with a free PCB for it)

This design includes the following features:
- Buffer as input stage with input biasing network
- Difference amplifier between input stage and variable gain stage, with the output of the difference amplifier being referenced to the cold point of the volume controller
- Linear potentiometer used as feedback element in an inverting amplifier, not as attenuator
- No output stage (almost)
- DC removal circuit (2nd order low-pass filter whose output is subsequently subtracted from the signal)

So basically bal to unbal, followed by unbal active volume control as part of a difference stage, then back to bal with passive balanced impedance output.

Has anyone actually built this preamp? If so, what are your experiences with it? And what do you think of the concept and design as such?



(EDIT: Just saw from AndrewT's post here that the EDN version of the article published here has some very valuable additional comments.)

Hi folks,

here for sale a summing amp also to use as line amp with two channels. Signal up to +22dBu. Balanced groundfree in/out with high quality studio transformers.
Can be used as summing amp in a mixer with an input rail or line amp with up to 20dB gain. For example also for long signal distances of up to 900ft / 300m for FOH use.
Incl. schematic and pinout.
Asked price is 75,- $ + shipping. Serveral available......(The cost of one transformer btw is about 110,- $), questions are welcome.....

regards

HP

Hi All,

SAE-3200 Tuner, as NOS originaly packed, for sale.
This was one of the smallest tuners from SAE. Bought it from the SAE-owner Morris Kessler years ago.
For forum members only 140 US$ + shipping. I have 5 of them.........

regards

HP

Hello...im not much of a stereo fixer but can fix almost anything else.
i hook up this used onkyo dx-7210 cd player and get this gear slipping sound so take it apart and find it is in fact two gears not meshing. I find this youtube video and this guy has the EXACT same gear problem. The issue is i cannot tell how he fixed the gears because its not in english. I tried for hrs. to translate the video to english with no luck. Im hoping somone on here can tell from the video what this man did to fix the gear problem. I can visually tell that the gears are not tight together when it cycles. Your help in this matter would be greatly appreciated. thank you
YouTube

Hi to all members. I am Kevin a retiree and a new member from Australia. I am interested in home theatre and 2 channel music. I have no technical skills but am fortunate that my son is a Electronics Engineer and designs, builds and repairs amplifiers as a hobby. He has the skills but has no time. I am hoping to find some projects to build and will coopt my son for the construction.

Hello guys,
I'm Renald from Concord, CA, USA. I've built the Pete Millett's NuHybrid headphone amp.
I'm glad to join this forum. It is a great place, thank you.😄

Kef Q100... yes i know that one. Do you really know that speaker?
Do you know that feeling when you see something, something that gets under your skin. Gently crawl under the skull and torture brain at night when you lie down, then gently whisper that driver it's the chosen one.

This is exactly how I felt when I saw the construction and engineering that was put into this driver. But the comments and various reviews indicated that it was just an ok speaker, and those things turned me off from buying it.

But wait someone opened the box and the crossover was only with three components.

One coil on midbass on tweeter capacitor and resistor.

Ok, I smell a rat.

This means war, Kef.

I prayed to the gods of DIY, and went to war against poorly executed Crossovers.

Made new enclosures, new measurements in new enclosures and these are the results.
Mic is Umik-1



Crossover



On axis



Of axis 0-10-20-30-40-50



3db/oct

I don't know exactly how the speaker behaves below 200hz due to the measurement in the room. This response is combined from two measurements, read approximation…



6db/oct

Having a clear out: I have a Passworks 6-24db active crossover PCB. As can be seen some the caps and trim pots have been installed. At the time I was unable to get the transistors from the DIYaudo, they are available now.

This crossover can be configured in many slopes and crossover points. There is a build guide section over on DIYaudio covering the build implementation.





£50 + shipping

Hey guys I just received a wondom bdm8 amplifier I ordered from their store on AliExpress. Just like all the Chinese boards there is little to no documentation on them so I was wondering if anyone here has one and if they can share their experiences with it? My initial impressions are that it sounds very good and seems to have plenty of power using an adjustable SMPS at 36v 10a but can go to 50v. I haven't tried anything over 36v yet but I will. Theres alot of connections on the board that aren't explained at all and was hoping that I can figure out what they are.

2023-12-18 Ian GB2023 in Now OPEN

Hi Guys,

Ian GB2023 is finally started after a long time of preparing. I thank you for your patience.
It took me pretty long time because there are lot of new and updated products in 2023.

To make your life easier, this time, I’ll list all items at https://iancanada.ca. You will have a total 12% discount for this GB because of the Paypal fee is also eliminated using credit card payment.

I separated products in different catalogs, and put many solutions and configurations in the Project sector. I believe that will be a great help to select products for your project rather than a long list. You will find more surprise if you put the projects into your shopping cart.

You will receive a diyAudio message with the check out instructions and the discount coupon code.
Please do let me know if you don't receive the message in two days.

Terms and conditions:

One year warranty for all finished PCB assembly. That means repairing service is free within 1 year from date of purchase.
If the damage is caused by your DIY activities, please kindly donate some money to my PayPal account to cover my labor of service. Fixing a board usually takes me 1 hour (troubleshooting, rework the SMT, test and repackage). Buyers need to pay round-trip shipping and parts in either case.
I cannot 100% guarantee a fix if it is badly damaged, for example, by short circuit or other critical failure.
I will also provide firmware upgrades service for free within 1 year from purchases; Buyers also need to pay shipping.
Please also kindly understand that I’m not responsible for debugging the user's DIY system, I only guarantee my products are functional. If you have any problem with your system, please post the issue on the thread, other community members and I will try our best to support.
All GB items are for DIY uses. All sales are final and no return and refund will be accepted.

Some useful links

Webstore: https://iancanada.ca
Documents: github.com/iancanada/DocumentDownload

New Updates: https://twitter.com/iancanadaTT

Streamer solutions: https://www.diyaudio.com/community/...fight-the-jitter.192465/page-414#post-7263122

DAC solution: https://www.diyaudio.com/community/...fight-the-jitter.192465/page-504#post-7478491


2023-12-07
GB2023 will be stated very soon. Thank you for your patience.

2023-06-11 9:43pm
Ian GB2023 for SC-Pure, FifoPiQ7, UcPure MkIII and so on

*Note1: If you want to join this GB2023, Please just put your ID and items to the interesting list at the end of this thread so that I can reserve the GB products for you. Of course you have no problem to cancel your items if you change your mind later because it’s just an interesting list.

*Note2: This post will be kept continuously updated for new information, so please come back often to check.

Normally I run a group buy (GB) every two years. 2023 is a very special year. COVID is gone, and I have a lot of great products released/upgraded or to be released. So, I think it's time to prepare for the new possible GB2023.

As usual,to express my thanks to diyAudio community members for their long time support, I’ll offer a one time 10% discount during the GB2023 run time window.

Some items are already released and available, you can buy them now by sending me the order form back to me if you don’t want to wait for the GB2023 discount.
All items will be listed here: https://github.com/iancanada/DocumentDownload

Thanks again.
Ian

GB2023 by Ian





























Here are the GB2023 new products (partly):

. SC-PURE 22.5792 / 24.5760 / 45.1584 / 49.1520 MHz
. RFX OCXO 45.1584 / 49.1520 MHz, Adapter KIT, SquarePi KIT
. FifoPiQ7
. FifoPiMa
. TransportPi AES
. HdmiPi Pro
. TransportPi Digi
. UcPureMkIII
. UCbalancer KIT
. LinearPi MkII
. PurePi
. UcPi
. UcConditioner MKII 5V and 3.3V
. MonitorPi and MonitorPiPro
. ES9038Q2M DAC MkII
. OPA861 I/V
. StationPi SMT
. StationPi Pro
. ShieldPi Pro/MKII
. GPIO extender

Free stuffs (partly):
. StationPi PCB (limited stock)
......

Other old products can also be found here: https://github.com/iancanada/DocumentDownload
My twitter: https://twitter.com/iancanadaTT

Streamer solution
https://www.diyaudio.com/community/...fight-the-jitter.192465/page-414#post-7263122


SC-PURE0 by Ian, on Flickr


FifoPiQ7_0 by Ian, on Flickr


UcPureMkIII by Ian, on Flickr


TransportPiAES by Ian, on Flickr


HdmiPiPro by Ian, on Flickr


PhaseNoiseComparison by Ian, on Flickr


OCXO_RFX_Audio by Ian, on Flickr


UcBalancer0 by Ian, on Flickr


LinearPiMkIIDual by Ian, on Flickr


OPA861_1 by Ian, on Flickr


GPIOextender1 by Ian, on Flickr


MonitorPiPro0 by Ian, on Flickr

ES9038Q2MDMII by Ian

ReceiverPiDDC by Ian

DAC solutions
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Does anyone have an opinion about these speakers? I can buy a pair, but one doesn't work (perhaps voice coil?). Still interesting to buy or should I look for another full range speaker?

When I search conversations for a key word, and I receive a list of results.

But when I click on the result- it just takes me to that Conversation- not the point in the conversation where the search keyword was found.

Is there a fix for this?

I am helping my kid build a Streamer out of an old Emotive Cd Player with a failed DVD drive. The Dac is a AD1955A and we are trying to make it work without the use of the onboard microprocessor. we found that the board has an unpopulated header for I2S. We cut the traces from the processor to the Dac chip For the I2S signal. And we are sending I2S MCLK, BCLK, WCLK SDAT from an old Rigisystems USBPAL board (to be replaced later). We have it working, but only at 44.1khz and 48khz. The usbpal and dac chip can go to 192khz. And we can see that the usbpal board is working fine. But we get no output above 48khz.

I found another post here in Diyaudio with one small mention that 48khz is the max without cpu support????

Can anyone expound upon this??? Is that fact and why? What does the cpu need to do to support higher sample rates??

How do you deactivate your membership here?

I have surface finished aluminium parts occasionally, usually with silicon carbide "wet and dry" paper, just by hand, and it works fine.
But I now have a scratched panel that is more than a square metre, plus its partner that needs to match.
The scratches are more than superficial, which will be a serious waste of time if done manually.
My first idea was a portable belt sander but there is a problem with choice of suitable abrasives.
A belt sander is fairly "harsh" so a non-woven Surface Conditioner Material (SCM, like "Scotchbrite" brand abrasive) would seem suitable because it provides a bit of cushion.
I have used SCM in a rotary sander with reasonable results but it doesn't seem to be easily available in portable sander belt sizes, only belt file and fixed machine sizes.

So ordered a 'burnisher" type spindle from AliExpress to fit my polisher/sander.
,

I haven't ordered abrasives yet, there's a choice of abrasive paper flap wheel, SCM drum, or abrasive paper/SCM hybrid.
Any recommendations?

A final option is a Mirka Random Orbit Sander, or a cheaper clone.
These look really nice with dust extraction that the burnisher lacks.

I first noticed them in videos from people who make very nice stuff, and it looks like what they really use and not product placement, so it seems the professionals' choice.
Any opinions on these?

David

The purpose of this thread is not to present an Nth version of JLH amplifier, but to apply to the JLH amplifier another technique of amplifier theory.
My theory is that, an amplifier should have all its output currents already circulating in its veins , after which ,it is the amplifier and not the PSU who is providing the power to the output, particularly at the transients . By this, the power supply delivers a continuous dc current , which means ,switching PSU can be used .I tried out this theory successfully on small scale using TDA1552Q in bridged class A , with extraordinary result . (see The Moon for six pence). the Moon for six pence

Instead of using two amps bridged I wanted to experiment now a single amp, bridged with a paire of capacitors . It also results with a single power supply configuration ,and also dc current only from the supply. Now ,what amp ,already well functioning and available in kit at affordable price, I would think of to experiment upon ? The JLH of course . So I bought a Chinese JLH1969 for 7.5$ in kit to modify .

Once I applied the basic modification , I was expecting enhancement in high or mid frequencies as occurred precedently ,but to my great surprise I could hear tube- amp quality bass sound . With further adjustments I obtained an unprecedented low frequency performance . With all technologies considered ,I have never heard such bass , as if I added a subwoofer to the system . Now this amp is going to be my refrence amp on this domain. Using another reference amp only in high frequency domaine , I succeeded to bring the JLH up to its 95% . Now the JLH1969 got sublimed ,adding both a subwoofer and a super tweeter to the system, delivering the widest spectrum of tonality I have ever heard.

I would feel myself guilty to keep it to myself such an extraordinary sounding amplifier ,which is so easy to built and so affordable that I hope DIY will be greatly satisfied .

https://www.youtube.com/watch?v=9IlT2yeOJ0g. My high frequency generator.
https://www.youtube.com/watch?v=1PdcmFvZvuI&t=570s. from 9:40 to13:50

These are the main sound sources I used to tune this amp for perfect reproduction .

Try to be pleased by these two musical pieces on any other amp than this one .
Kokoriantz.

I'm looking at power conditioner advice videos and some of the people say that having a dedicated mains connection and extra earthing can help too.

It strikes me that the best option (for my home hifi setup) would be to get a large enough battery and a pure sine wave inverter.

The price looks to be similar to a conditioner but it seems to me to give a better result, I could also charge the battery on a solar panel and have it completely disconnected from the mains power.

Am I wrong?

Hi I'm somewhat new to tube amps but have admired them for years. Nostalgic I guess. I ordered a PCB from china single ended KT88 HiFi. I was hoping someone might have some information on this schematic.

I have looked at many schematics but have not come up with anything as of yet. Hoping for explanation of circuit, but have figured out lots so far.

I'm not sure about the filament jumpers to the KT88 tube. Maybe if you have a different supply voltage. I have figured out why the 6SL7 filament voltage is floating at 80v.

I still need to do some research on the OTP connection and 3.5k specification. But if you have info you want to share it would be appreciated.

Hey guys
Newb to these @iancanada Ian Canada/rpi DACs, but
not to diy.
Looking for some help putting together an order list/parts list and component layout.
I’ll start with my goals.
Looking to build a “high end” diy DAC/Streamer Roon endpoint solution for a second system (DIY Altecs with Yamaha AS2200)
All I want is LAN input and XLR output
I’ve watched all the Gabster videos so I understand the iancanada components needed (fifo q7, dual mono dac, monitor,screen) what I’m confused with is powersupplies.
I don’t want 3 ifi plugs connected to this
Would love a single IEC solution to power the supplies. But what supplies do I need?
I have a dual 5v 3a Talema LPs here I could cannibalize if needed. Not trying to have 5 huge cap sets like the Gabster either lol.
Basically if someone could say order these and let’s go.
We will need a chassis too
I have kids and can’t do the exposed stacked look.

Thanks all!

i was able to turn the gain on my Rockford Fosgate Power T400X2ad amp all the way up with my OEM head unit, but now that i switched to a aftermarket head unit (KW-M595BT) the left channel of the amp clips, regardless of wether it’s the right or left side rca cable plugged into it. i’ve gotten 2 more of these amps to see if the original amp had just broken, but the issue persists.

My name is Eagon, and recently ive gotten quite a bit of interest on speakers.

About 7 months ago i replaced my car’s speakers with better ones, and its snowballed from there. now i got 2 12’ subs, and 2 amps.

Im hoping to connect with people who are a bit more knowledgeable on everything car audio related, as i still have a pretty faint idea of what exactly i’m doing, and would love to learn everything there is to learn about this stuff.

I am modding a DAC and have another that is untouched so would like to compare them by switching between them using a remote control.

Both are connected to Cyrus Pre and but I don't have a remote for it.

I use an Audiolab 8000 remote to control a Cyrus CD DAD3 player which can also control the volume on the Pre but it does not change source.

From this I conclude there has to be an overlap in the codes sent by the Audiolab remote for the Cyrus components to respond. (I seem to remember using a Marantz remote to control the same CD player).

Does anyone know if the codes sent by remotes are published on the Internet?

I cannot use an universal programmable remote since I don't have one that can select source on the Cyrus Pre in order to program it.

I recently got bitten by the vinyl bug and bought some Technics separates and a decent turntable. I am looking for other Technics enthusiasts for guidance on my journey back into analogue HiFi. Thanks

I have a Simpelstark amplifier for sale. I have downsized and no longer have a component system. I think I built this amp in 2021. It is in working order. Some background and details on the amp can be seen here: https://www.diyaudio.com/community/threads/simpelstark-odnf-amplifier-boards-gb.341363/
$350 SOLD

Hi everyone,

I’m new to this forum and wanted to introduce myself. My name is Gregory, and I’ve been passionate about audio for several years now. My journey into the world of audio started when I discovered the beauty of high-quality sound, and I’ve been hooked ever since.

Recently, I’ve been diving deeper into the DIY audio scene, particularly building my own gear like amplifiers and speakers. My current setup includes Eversolo A6 Master Edition, Marantz PM KI Pearl and Quadral Aurum Vulkab VIII. My goal is to keep improving my system’s performance while learning as much as I can about DIY audio.

I’m looking forward to connecting with other audio enthusiasts here, learning from your experiences, and exchanging ideas. Thanks in advance for the warm welcome!

Best regards,
Gregory

I'll be posting a troubleshooting thread for a CS-800X that flickers power lights rather than powering on so hopefully this turns into something helpful for others.

Hello!

I'm Mimi. I've always had a strong interest in electronics, particularly in building and tinkering with audio equipment or repairing vintage devices since I was a kid.
I’ve spent a lot of time learning about electronics in college and I am always looking to expand my knowledge and skills.
I’m here to ask questions or share details about projects or doubts that I will possible have, anything, really.

Regards and have a nice day.

,I am yash from India Delhi And very well intrest in audio and engineering and in making of speaker with quality

Hi there,

This buffer proves very difficult to stabilize. It is the result of a collaborative effort between Kenpeter and myself, and had never been tested IRL, just in sim.

Since I needed a high-perf buffer, I decided to give it a try.

It is based on well-known principles for this kind of circuits, ie. keeping all the conditions of the actual buffer element as stable as possible, but here this principle is pushed to the extreme.

The circuit is perfectly stable in sim, but my prototype oscillates madly.
The oscillation is a maximum amplitude squarewave of ~1MHz, which led me to think that the initial conditions triggered some kind of repetitive latch-up and let go, but it isn't the case: in fact, the cause is a VHF oscillation that builds up very quickly and ends up saturating everything, and upsetting DC bias-points.

What I have tried:
I tried to kill the bandwidth at every point possible; the only completely effective cure was a C-B cap of 10nF on Q2. Needless to say that it not only kills the oscillation but any usefulness as well.
The second best was a RC of 220ohm/47pF between the base of Q1 and the ground. I found this one by touching the point with a screwdriver, but it doesn't not remove the oscillation completely: it remains present as very short VHF bursts separated by a few ms, when the bias points have the time to settle.
Nothing else seems to have a positive effect.
In sim, I have tried to reproduce the effect by adding parasitics here and there, but I can only get an oscillation if I add a grossly exagerated parasitic cap (>15pF) in parallel with the 1µH (this one provides the compensation of the linearizing loop).

In general, I manage to tame even the most indocile beasts, but this one proves a tough nut to crack. The fact that the sim and prototype do not converge is problematic, because I built directly the definitive version, and making physical alterations is seriously unpractical.

One more detail, the prototype has been properly implemented from a physical point of view, with decouplings, shieldings, etc.
For my work, I routinely develop and build test-jigs good to 500MHz~1GHz, which means I know the rules and apply them properly.

Any ideas?

Hello all,

New here, and fairly newbie in DIY based in the UK.

I have a modest hifi system, A&R A60, Manticore Mantra and Ariston RD11 (a very early one), hooked to a pair of Epos ES14.

I am now in the process of recapping a Revox B750, which I hope will be a nice upgrade. I have little knowledge but I tend to be willing to learn.

Thank you for welcoming me

Does anyone have info about the clock used in the Musical Fidelity M1 DAC - photo for an early model is below but the later ones look similar. Ideally I would like to view the datasheet - reason for asking is I am looking to replace it with TCXO or maybe OCXO - natrually I'm interested if someone has alredy done similar.

Hi all, i'm new to the site so please bear with me!

I have recently changed a laser assembly twice(!) in a cyrus cd8x and still have a problem. The cd player now plays the discs, but is prone to skipping or 'getting stuck'. I'm going to db check the mech etc but I am quite sure that it is okay. Am I suppose to tune the transport slightly for the player (laser intensity etc), is there a known issue between the disc platter of the new transport and the old clamp, am I suppose to follow through witrh my threat and cut the dam thing down into tiny pieces and feed it to the player devil?

Please help!😱

I spend most of my time here in the multi-way forum. So I'm posting this here because there have been discussions looking for amplifiers for DIY active speakers.

https://bellarossafabrica.net/6-channel-amplifier

Can an advertisement that has been placed have the title modified? Can the advertisement be removed? Thanks

Hello,
This is my first thread here so please forgive any mistakes. English is not my native language.

I started building a DC blocker for my AV set-up devices: Pioneer VS-LX305 multi-channel amplifier in a 7.1.2 speaker configuration, Panasonic HD DP-UB424 BD Player + a few smaller components.
When building a DC blocker, I wanted to use a ready-made solution. No, not high-end because I don't expect a miraculous improvement in sound😉 I just want to proactively protect the equipment from a possible DC component so I bought a medium-sized module on Aliexpress. The schematic was not included, I drew it in LTspice:



Question #1:
What do you think about such a DC blocker? It seems a bit oversized or maybe even exaggerated, but it is built rather classically.

The total capacity is 9900uF and consists of 12 pieces 3300uF/10V capacitors connected in opposition (as bipolar). I want to believe that the Nichicon print on the capacitors means real Nichicon and not "clones"😉

I have doubts about the huge number of diode bridges. There are 6 bridges (KBJ2510 1000V / 25A), which means there are 24 diodes in the system. Please correct me if I'm wrong: diodes connected in this way will limit the maximum reverse voltage on the capacitor pairs to a maximum of 2.5-3V. In my opinion, this means that the reverse voltage on a single capacitor will be 1.25-1.5V. It seems to me that this is a bit too much. I would prefer to stick to the maximum reverse voltage of 1V on a single capacitor.
On the other hand, diodes connected in this way ensure blocking of the DC component to 3V. In my home installation, I absolutely do not expect such a high DC component, so the value of 3V in my case is oversized.

Question #2:
Would removing two bridges with diodes D17.. D24 be a reasonable move? What do you think? This would reduce the reverse voltage on the capacitor pairs to a maximum of 2V. Of course, the DC component in the home network would then be blocked to 2V and not 3V.

I would be happy to hear all opinions on the subject I have raised 🙂

thinking of one thing.. for those of you who have backup units, won't these degrade over time when they are stored? thinking of capacitors and belts for example

All 6 woofers perfect working order- pickup 44405 $75 for all 6



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