Fake STK3152/STK3102

Hello!


I own a PM80 SE that has a failed STK3152 that replaced an already failed 3102 around 15 years ago. It's an insane coincidence that David created a replacement just before I was in need for a repair.


A friend and I ordered a few boards made with David's design from China which will arrive next week presumably. I will take pictures and report if and how well it works!
 
The replacement is working and producing great sound!


Pics:



U890IzT.jpg
lO8826D.jpg
LUAYCdF.jpg
 
I didn't think about the thickness when I ordered the pcb. Now I would order it definitely in 1mm or thinner.

The STK that was in it had a heatsink merged with the pcb.

Maybe in a few years it blows again then I'll optimize the heatsink 😀 So far it's been running day and night
 
I attempted to fix some of the weaknesses of the original module and the fakes. Splitting the high voltage dropper resistor that seemed to degrade into R7/R10 and the higher power output devices should help reliability.
If anything is getting too hot, let me know.
 
This is the latest KiCad 5.1.0 generated version.
I see what happened, KiCad has changed the Gerber file names slightly and I mixed a version.
The circuit is unchanged, I have just cleaned up the tracking a little to improve clearances and maximised copper area on the output devices
 

Attachments

I attempted to fix some of the weaknesses of the original module and the fakes. Splitting the high voltage dropper resistor that seemed to degrade into R7/R10 and the higher power output devices should help reliability.
If anything is getting too hot, let me know.


The split is clever. Didn't notice that until you mentioned it.

I honestly doubt it will break down anytime soon by overheating. If that counterfeit lasted for over a decade your design will for sure
 
The unknown is the heating when the speaker output is shorted. What happens to this module depends on the details of the power output stage wrapped around it. Some STK3102 based amplifier schematics that I have looked at seem to lack output protection