Yamaha CS80

On a related note, anyone trying to work on a CS80 (or other analog
synth) needs the following:

anti-static wrist strap - about $10
digital voltmeter - about $20 - $100 new/used
analog oscilloscope/probes - about $50 - $100 used (only need very
simple 10MHz 'scope)
non-conductive trimmer/adjuster - $5
tuner
   a $30 chromatic tuner will work
   Here's a cheap replacement for a strobe tuner if your 'scope has an
X/Y mode (most do)
      1) create wave files of sine waves at the reference frequencies (I
used Sound Forge and can post the files)
      2) attach your soundcard output to the 'scope's X/horizontal input
      3) attach your CS80's output to the 'scope's Y/vertical (normal) input
      4) set the sound to loop/repeat
      5) set the CS80 to sine wave as directed in the standard tuning
instructions
      6) when the frequencies match, the 'scope squiggle will be a
static, or very slowly changing line or ellipse
         Look at this excellent website that shows what it will look
like: http://www.mathcats.com/explore/lissajous/lissajous.html
         Make X and Y frequencies the same and then change one slightly
to see the "beating" effect. Notice that you can
         change one frequency by octave (double, half, 4-times, etc) and
it still works, so you don't need to change the computer
         sound file to tune different octaves.


If you're going to be replacing parts, add:
Good, grounded tip soldering iron -
Soldapullt solder remover - $10
Solder wick - $10

And, if you're going to replace all the CMOS chips:
de-soldering station - $100 - $300 new/used (I bought one and then sold
it when I was done)

Anything I missed?

 David