Gary D Olson
Skilled Tightwad
I have the service manuals and can solder, but is that enough with either of these pieces?
I have the service manuals and can solder, but is that enough with either of these pieces?
http://audiokarma.org/forums/index.php?threads/yamaha-c-70-project.747782/
There's a good thread by sonavor here covering the full restoration of a C-70, it should help a lot.
His component choices are very good too, I'd be inclined to use the same ones.
It probably goes without saying, but do be really careful with the orientation of parts and when soldering (to not create any bridges etc).
Any small slip-ups can result in mass damage (I speak from experience sadly!) so triple check everything before powering on again after service.
Edit - also something you might already know, but make sure you buy all components direct from a reputable electronics source (eg. mouser), don't buy anything off ebay etc - counterfeits galore.
Also, one of the biggest problems with old Yamaha amps is cold solder joints (they look dull and often have a faint ring / crack around the leg of the component) so it's worth re-touching all those with a spot of fresh solder. I've found that re-melting the existing solder isn't as good usually.
Good luck!
Probably be able to DIY. If the C-70 is presently working.
Thanks for the advice. I did read sonavor's thread (twice) and am prepared to follow it as best as possible. Everything will come from either mouser or digikey. Thanks for reminding me to fix cold solders. I'll be sure to take your advise and use fresh solder.
Did the advice also suggest to replace with component values like are on the board, not just order what the SM calls out?
Probably be able to DIY. If the C-70 is presently working.
I like to check the components I'm pulling out and putting back in so I'd recommend one of the inexpensive component checkers you can buy on ebay. It's probably rare as anything but I'd kick myself if I had to track down a bad cap or diode that I put there.
If you're going in may as well do the trimmer pots, heat sink paste as well as spot checking some of the fusable resistors to see if they are holding spec.