Again, its not just the heat.
those chips dont get this warm to harm themselves. even in an enclosed space without venting holes.
its the potting compoung expanding and contracting when thermal cycling that seems to rip solder pads apart.
The best way to prevent thermal cycling would be to leave the amp running all the time or just removing the compound entirely.
since i removed it and fixed the solder joints, my pa5 is running as if it was brand new, for longer than it ever has been.
best way to remove it is with a lot of heat and care.
heat to 250..300C using a heatgun, and carefully scrape away the epoxy in chunks one by one. takes an hour or two and you may rip something off the board...
Because of that hassle,
im working on a replacement d01 module right now
for everyone to fix and make their pa5 live longer.. now that its discontinued
As im on a tight budget, im glad a kind ASR user donated me a PA5 for this purpose. thanks again.
its in its testing stage, parts are still missing.
When its ready, i wont sell them by myself, but i wouldnt say no to any donation
You can order the assembled PCB's on the usual chinese pcb websites or solder them by yourself.
I sanded down the D01 4 layer pcb to see where stuff is going and measured all parts.
View attachment 280601View attachment 280602View attachment 280603View attachment 280604
ive drawn a schematic and made some PCB's, and i will release it when im 100% sure it works properly.
I cant measure SINAD tho, dont have a APx. But since its using the same parts, it shouldnt differ much.
i want to make different versions of it, like for those people who want to do opamp swapping with dip8 sockets.
View attachment 280605
its missing the bottom side parts still, since they didnt have opa1612 in stock at that time.
I will post an update soon with more details.