so ive had my 857 for about 4 years now and overall its a solid rig but the receive audio has always bugged me a little, its just kind of thin and harsh especially on SSB. been reading about the collins filter mod and also the electrolytic cap replacement on the audio board. some guys swear by it and others say they didnt notice much difference.

my question is has anyone actually done both mods on the same radio and if so was the improvement noticeable enough to justify cracking the case open. im reasonably comfortable with a soldering iron, done some work on older tube gear so small SMD stuff doesnt terrify me but i also dont want to mess with something thats been working reliably for years if the gain isnt worth it. the collins filter in particular seems like it could make a real difference for CW but i mostly do SSB and some digital so maybe its not even the right mod for my use case.

also if anyone has the specific cap values handy for the audio board replacement that would be helpful, ive seen different numbers floating around on different sites and im not sure which version of the board mine has

did the cap swap on mine maybe two years ago, used a mix of Nichicon fine gold series where they fit and standard low-ESR electrolytics elsewhere. honestly the difference was real but subtle — less harshness in the high mids, slightly better low end presence. not a night and day thing but if you spend a lot of time with headphones on it adds up. worth doing if the caps are old anyway just from a reliability standpoint.

i skipped the collins filter mod because like you i mostly do SSB and the stock murata ceramic filters are fine for that. the collins really shines for CW where you want that tight passband. for digital it probably doesnt matter either way since the DSP in fldigi or whatever youre using does most of the heavy lifting. if you do open it up check the PA board heatsink compound while youre in there, mine had basically dried out completely and the thing runs noticeably cooler now with fresh stuff on it.

cant really speak to the specific cap values you need but W4RT used to sell a whole mod kit for the 857 that had everything you needed, not sure if theyre still around though. the schematic is on the yaesu site if you can find the right service manual version for your serial number range, thats probably your best bet for confirming what your specific board has.