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Topping PA5 fix - D01 Module Replacement for everyone

Just checked ebay to see if anone is selling a "for repair" PA5 in the UK. Thought it might be a way of getting one at low cost for playing with.

No joy.
 
If another manufacturer had copied the circuit, they would have introduced the same error as always, just like AIYIMA with the A7, Breeze Audio or even Fosi Audio with the new V3.
Hi R68, What is the error?

Thanks, Gary
 
I've been playing my PA5 (I bought it used on Fleabay) with gamerpaddiy's single sided replacement board now for a good week or two and I'll admit the PA5 is really a wonderful sounding inexpensive Class D amp, even using the powerbrick that came with it. It doesn't have that flat sounding Class D sound that many of the other low to moderate cost amps do.

Cheers,

Pete
 
Ive been working on the PA5 for a while now after mine died suddently,
like many others

Most of the PA5 units develop a crackling, hissing or just go a little silent or completely dead on one or both channels.
This issue is related to the potted D01 module.
Its potting compound expands and contracts when it heats/cools and rips off components in the process.


See my teardown and analysis of it in the PA5 thread here

After some kind ASR member donated a broken PA5 to me for research purposes, i went on an reverse engineered the D01 module.
My intention was to make a replacement module for anyone to build / buy so their PA5 will live again, and hopefully forever.

Its PCB and Schematic files are open source, and anyone who wants their PA5 fixed without dealing with the support or is out of warranty for drilling holes into it... can just order those at their favourite pcb house and even let them assemble it for you.



So ive started by depotting the module, which i did on my previous unit aswell and its now been running fine ever since. longer than before.
View attachment 281869

and after stripping & measuring all components, i sanded down the 4 layer PCB
View attachment 281862View attachment 281863View attachment 281864View attachment 281865

after that, i reversed the schematic from it.
View attachment 281870
(ignore mute sw L/R, i suspect its mute but could be a floating ground, havent looked into it yet)


And made & ordered some PCB's
View attachment 281872


After assembling the other side and testing them, they worked flawlessly.
View attachment 281866
View attachment 281867
View attachment 281868

They work, they sound good. Its a worthy replacement for the original Part which will last much longer.

instead of OPA1612 i used OPA1656 since they were in stock and not too expensive, they are very good too, i dont hear any difference.
i cranked the volume to max with nothing playing and didnt hear any hiss / hum.
and i got no way to measure the SINAD of it unfourtainly.


I will not Sell these myself. But i made the design open source so anyone can order pre-assembled PCB's at the usual chinese PCB makers.






The Project can be found here:
Just click on "Editor Open" on the top right.








i havent chosen specific parts for resistors and capacitors in the Bill of materials, when you order them you gotta select your own.
Because sometimes the ones ive chosen are not available 3 months later anymore and you gotta find suiteable parts anyways.

Some component values are weird, just select the ones that are the closest, it doesnt have to be exact. topping used some parts in series to get there like 3x3.3k instead of 10k..



There will be a few versions of this module, mainly focussing on putting every component ontop so Assembly gets way cheaper than both-sided, also DIP8 sockets for those opamp swappers out there. but overall it will stay the same.

just dont pot the module in epoxy or tar.. we've been there. it really doesnt need to be thermally equalized..
Also you dont need a metal shield around it. the D01 metal case is just for looks, it isnt actually connected to Ground for shielding.


edit:
the module i assembled for testing uses slightly different values and opa1656 instead of opa1612 as mentioned, i noticed it having less gain. the original one had its earbleeding volume at about 2/3, this one i can crank to 100% i also noticed a bit tighter bass, at least im seeing the cones move a little more than before.. or im just cranking it further for some reason.
i used 10k instead of 9.9k, 6.8k instead of 6.99k, 1.2k instead of 1.21k, 200 instead of 205ohms and so on.

Wow ! Amazing work.

Soon we'll see you employed at Topping lol

Isn't this how JY got his job there ?
 
Very good and nice work ! congratulations for this mod ! If it prolongs the life of the PA5, I say hats off and well done!
There is also an alternative to the PA5 / RA3, the latest 3E Audio Module which offers a nice Sinad of 105.8DB / THD+N in 4Ω / F = 1kHz, Po =5W = 0.0007%
And above all, which should be much more reliable over time) :

 
Daniboun, I applaud all the work you do introducing the community to the range Class D amps, and possible modifications to said units, but I'll have to disagree with your statement about the 3E amps. I've owned several of them (w/wo PFFB) and for all the power they can crank out, yes with pretty black backgrounds, they all just have that (blah) class D sound. The unique use of cascading op amps in the PA5, along with whatever circuitry tricks they also did, really led to a much more rewarding SQ than any other class D in this price range. I've implemented gamerpaddy's module changeout (also de-potted the original module which was still working when I took it out) and this little unit is really is a great sounding amp.
 
Daniboun, I applaud all the work you do introducing the community to the range Class D amps, and possible modifications to said units, but I'll have to disagree with your statement about the 3E amps. I've owned several of them (w/wo PFFB) and for all the power they can crank out, yes with pretty black backgrounds, they all just have that (blah) class D sound. The unique use of cascading op amps in the PA5, along with whatever circuitry tricks they also did, really led to a much more rewarding SQ than any other class D in this price range. I've implemented gamerpaddy's module changeout (also de-potted the original module which was still working when I took it out) and this little unit is really is a great sounding amp.

Hi,
I own the PA5 myself, you are confusing the DS_EAUMT-0260-2-A_Rev1.0 module and the very latest 3E Audio module 3E Audio 260-2-29A (fully differential with Coilcraft Inductors / PFFB on).I noticed that many readers confused the two 3E Audio modules. These two modules have nothing to do with each other

I am referring to the July 2022 module, see the measurements on my thread.

So if you take a good look at the measurements, you will see that this new module has similar performances to the PA5 /RA3

Sinad of 105.8DB / THD+N in 4Ω / F = 1kHz, Po =5W = 0.0007% so It's pretty close to the performance of the PA5/RA3 (Sinad 106DB / 5W)

Now if you consider that my first PA5 died after 6 months and that the second too and that my LA90 stopped working after 1 year, then I can say that Topping produces amps that measure well but which are not made to last... Hence my attention for the latest 3E Audio Module

1694359234756.png

1694359267317.png
 
Oh my God, why did they hide this nonsense in compound-filled modules?
IP protection, and it's legitimate, but it caused more problems than it prevented. If they hadn't used potting material the PA5 would have "taken over the world". It was the right amp at the right time and it would have had massive sales. Topping's image would not have taken a hit. It would have been a win win across the board.
 
Agreed jmiliar...It is a phenomenal sounding Class D at this price point, and slightly above. Their chemists/chemical engineers really failed them on this one....or was it their patent attorneys?
 
Agreed jmiliar...It is a phenomenal sounding Class D at this price point, and slightly above. Their chemists/chemical engineers really failed them on this one....or was it their patent attorneys?
The really sad thing (as the OP to this thread shows) the IP obfuscation can be circumvented by one guy working alone in a few hours. How long did it take their competitors do you think?

Topping near massacred their own reputation for absolutely no benefit whatsoever.
 
The obsession with protection leads to crazy decisions.... Topping implemented a pseudo anti-reverse engineering strategy without going through quality control. By wanting to skip the steps we end up endangering our image.
 
sure
the amp was just idling with no speakers attached, thats why its so cold
max. temp reached by the ne5532 after a few minutes is around 65°C, that cam isnt very accurate.
View attachment 312969
View attachment 312968View attachment 312967


I purchased 2 pure copper passive heat sinks, measuring 15mm x 15mm, to install them in the replacement module by gamerpaddy. Each one covers one NE5532 and one OPA1612, meaning, each heat sink covers 2 different op-amps. I haven't installed them yet; it might not be necessary, but I believe the NE5532 is close to its operating limit (70°C). Do you think there might be an issue? @gamerpaddy

1695088407154.png
 
its a recommended range, not a absolute limit. just leave it as is.

no one reported a failed module yet
and i forget to turn my pa5 off frequently and only notice it after days.... not a single issue so far.

the risk of a tiny heatsink falling off and shorting out components is far worse.
 
I purchased 2 pure copper passive heat sinks, measuring 15mm x 15mm, to install them in the replacement module by gamerpaddy. Each one covers one NE5532 and one OPA1612, meaning, each heat sink covers 2 different op-amps. I haven't installed them yet; it might not be necessary, but I believe the NE5532 is close to its operating limit (70°C). Do you think there might be an issue? @gamerpaddy

View attachment 313006
I'm running gamerpaddy's modules (one sided & DIP8; 8 ohm speakers) and there really is no reason to put heatsinks on the op-amps...they really don't run that hot when music is playing through them. I know the heat pictures make it look like they're burning hot but they are within range of heat tolerances. Better to drill a bunch of holes in the casing right above the module but even that may be just for psychological satisfaction.

The TI data sheet says the operating free-air temperature for the 5532 is 85C while that of the 1612 is 85-125C (if I'm reading that right).

JMTCs

Cheers
 
I'm running gamerpaddy's modules (one sided & DIP8; 8 ohm speakers) and there really is no reason to put heatsinks on the op-amps...they really don't run that hot when music is playing through them. I know the heat pictures make it look like they're burning hot but they are within range of heat tolerances. Better to drill a bunch of holes in the casing right above the module but even that may be just for psychological satisfaction.

The TI data sheet says the operating free-air temperature for the 5532 is 85C while that of the 1612 is 85-125C (if I'm reading that right).

JMTCs

Cheers
Bear in mind also that the surface temperature of a device will always be much higher than the free air temperature. This is taken into account in the thermal design of the part.
 
Hi, is it possible to remove the original D-01 from the bottom, cutting the pins and desolder?
 
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