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Capacitors on bottom of PCB (206A)?

Started by emutchler, January 24, 2022, 06:51:10 PM

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Hey everyone, so I started working on the PCB today for my 206A and when I flipped it over, there were a few ceramic caps that were soldered on there. I cannot seem to find any mention of these in any schematic or anything. Should I go ahead and remove these or do they likely serve a purpose? I attached a photo for reference.


Upon further analysis, it appears that each of these caps are placed in parallel with the base and emitter of transistors on the PCB. My knowledge of electronics is not good enough to know why these might be there, but I figured it might help someone else diagnose my issue.


Might be an "anti-hiss" mod. I recall something like this at least for the 200. But there the caps are between base and collector.

Vintage Vibe schematic:


I got an answer from the folks at Tropical Fish Vintage - apparently these were added by the factory to improve the amp design. Also, in case anyone is interested, there are similar ones on the pickup as well.