What are the two holes in the case and bar? Aren't they for screws to oppose the heatsink bar to the chassis, by design?
Looks like this design clamps the bar to the chassis from the outside. Without using nylon screws and silicone thermal pad, the bar is going to connect the chip thermal pad analog ground to the chassis ground.
On blocks for my amp, I use screws from the PCB to clamp the block to the chip (with thermal paste in the small pad mesa). The block itself is clamped to the chassis floor with PCB stand-off screws and there is a silicone thermal pad between the block and the chassis. Here is the block closeup.
On blocks for my amp, I use screws from the PCB to clamp the block to the chip (with thermal paste in the small pad mesa). The block itself is clamped to the chassis floor with PCB stand-off screws and there is a silicone thermal pad between the block and the chassis. Here is the block closeup.
Hard to care much for an amp that sells for $40. 🙂
But good design only needs to be done once and they did everything just not with care to the finer points: no thermal paste, no silicone pads, screws grounding the block, not enough thermal dissipation in the case. Etc.
The Topping PA-5 amp (TPA3244 I think?) that was so highly regarded for its ultimate low distortion better than the Benchmark reference amp had thermal issues that caused early demise as well. It’s not cheap ($399 if I recall) but still has issues. Mostly from stuffing it into too small of a package and not accounting for thermal issues. Not too many people like those amps now because they died in a few months (or a year in my case). I bought one to evaluate and it’s now dead on the left channel about 2000 hrs in. I think the solution is the secret sauce opamp block needs to be replaced by the aftermarket reverse engineered one offered by a member here on DIYA.
Users on ASR report about a 50% failure rate. Ouch that is high.
Member Plott built a wonderful TPA3255 amp - look how much space and room he leaves inside the box. No thermal issues here.
Compared to Topping PA-5 interior. Cramped and prone to overheating.
But good design only needs to be done once and they did everything just not with care to the finer points: no thermal paste, no silicone pads, screws grounding the block, not enough thermal dissipation in the case. Etc.
The Topping PA-5 amp (TPA3244 I think?) that was so highly regarded for its ultimate low distortion better than the Benchmark reference amp had thermal issues that caused early demise as well. It’s not cheap ($399 if I recall) but still has issues. Mostly from stuffing it into too small of a package and not accounting for thermal issues. Not too many people like those amps now because they died in a few months (or a year in my case). I bought one to evaluate and it’s now dead on the left channel about 2000 hrs in. I think the solution is the secret sauce opamp block needs to be replaced by the aftermarket reverse engineered one offered by a member here on DIYA.
Users on ASR report about a 50% failure rate. Ouch that is high.
Member Plott built a wonderful TPA3255 amp - look how much space and room he leaves inside the box. No thermal issues here.
Compared to Topping PA-5 interior. Cramped and prone to overheating.
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Some user put this amp vertical and report drop of the temp about 5C. Well, i think its not just about the chip it shelf, if you put the electronic stuff with no ventilation, the other part will quickly die.... they promote this amp use 'audiograde' cap (Elna) and we know that 'audigrade' cap is a cap with only 85c rate.... so im sure in 1-2 year the amp will begin to failure. My best bet is re paste the amp, play with 36v adaptor, and someday re cap with 105 rating cap and move the amp to big case with lots of mods
It sell with $110 price tag (exclude shipment) for 1 mono amp without adapter, and i got it under $40 (include shipment) ...for TPA 3255 with PFFB and good review, who can resist that temptation? And i'm agree with your opinion, why on earth they race to make miniature amplifier, cage in small enclosure and pushed to their limit? i got 3 amp TPA32XX series and all of them are naked.....they sound clean without any interference and surely damn loud in 36v for my HT
Attachments
Found the D-01 reverse engineered board by member gamerpaddy. Will attempt to fix it now. I guess I need to use a hot air gun to desolder the existing D-01 brick.
I use mine in nearly every build. 
You were not kidding about having a hard time deaoldering that unit! It took 20 minutes of hot 390C air from my hot air pencil to finally dislodge that old unit. It was smoking hot. I hate having to heat anything up that hot - and I used a soldering iron to add local heat as well. Cleaning out the old solder holes was a pain too. The new one is installed. Fingers crossed that it works.
@xrk971 Great video of the heat block install. What thickness of silicone pad do you recommend between heat plate and chassis?
Also, which DC socket do you recommend when keeping the power supply out of the enclosure? I need to install one by tapping the thick alloy casing and screwing in the DC socket housing. However I am not sure if it is OK to install the metal DC socket housing VS the plastic DC socket housing version, as the DC negative signal from power supply will obviously be in contact with enclosure.
Thanks for any input.
Also, which DC socket do you recommend when keeping the power supply out of the enclosure? I need to install one by tapping the thick alloy casing and screwing in the DC socket housing. However I am not sure if it is OK to install the metal DC socket housing VS the plastic DC socket housing version, as the DC negative signal from power supply will obviously be in contact with enclosure.
Thanks for any input.
Those sockets aren’t good for the kind of current the TPA3255 needs if you want full power capability. Don’t let the PSU GND touch the chassis. So the metal one is no good in any event.
The connectors used for RC drone battery charging are great for DC power and high current.
XT60 panel mount works well. Good for 90A!
https://a.aliexpress.com/_m0tMTiJ
You can get the mating plugs with pigtails or bare. They look like this.
https://a.aliexpress.com/_mMebAkX
This is what I used on my Vera-link BT amp speaker out.
Alternatively, Mil-Spec round connectors work as well as Neutrik power connectors.
The connectors used for RC drone battery charging are great for DC power and high current.
XT60 panel mount works well. Good for 90A!
https://a.aliexpress.com/_m0tMTiJ
You can get the mating plugs with pigtails or bare. They look like this.
https://a.aliexpress.com/_mMebAkX
This is what I used on my Vera-link BT amp speaker out.
Alternatively, Mil-Spec round connectors work as well as Neutrik power connectors.
The repair of the PA5 amp works like a champ. Without these DIY fixes I would have a $400 door stop. Similar thing happened on my SMSL Su-9n DAC. The clock chip went bad from thermal burnout. Someone reverse engineered the part (it was ground off on the chip) and I swapped out a $6 part to save a $400 DAC. Still working like a champ. The original clock was a bad low quality part that overheated.
That was a general pic, but thank you. I have a couple 10A rated 5.5 x 2.5 female DC sockets to try.
Precisely for this reason TI says that the thermal pad needs to have a good connection to PCB ground. (Datasheet page 32 note T3)