Hi all.
I don’t think frequency counters are useful at all for tuning. You can do it all - and very quickly - just using a reference tone and beating tuning by ear or strobe tuner or Lissajous Patterns (
http://www.youtube.com/watch?v=t6nGiBzGLD8). I just use ClearTune on my iPhone to play a sine wave at the highest pitch C and then do the first tuning step to match. Once you’re close, it’s very simple to tune it in perfect by beating. I even posted some sine-wave mp3 files here a few years ago -
http://groups.yahoo.com/neo/groups/yamahacs80/files/Tuning%20tonesOnce I’ve done some tuning step for Channel I, move the balance to hear both channels and adjust the same trimmer for the matching Channel II card.
The only trick is to keep the electronics warm. Unless you’re in my SoCal garage in the afternoon, the room temp is probably lower than the insides of a CS80. Just warm it up for a while and prop the lid up just enough to get to the trimmers and close it in between steps to get it warm again. I used to lift up the card rack until I realized a few years ago that Yamaha put the trimmers at the top end of the cards so you can get to them without lifting up the cage. d-oh! Just be careful to bend the wire bundles up out of the way.
David