Quote from: J M Fahey on March 09, 2015, 02:06:31 PM
What happens if you turn it on with all controls set to 0 ?

It happens with all controls set to 0  and nothing plugged into amp. 

Getting multiple pops when turning on this amp in vibrato or chorus mode.  Multiple pops signal first detected at last IC stage of vibrato prior to going to power amp stage.  Has anyone seen this?  Is this just a normal occurrence for this amp when powering up in this mode?  When in the normal mode, I only hear the normal turn-on pop.  Of course, the vibrato circuit is not connected to the power amp in this case.

Quote from: DrGonz78 on February 20, 2015, 04:16:47 AM
I originally type in a web page you had to have an account to get the file. So here I have the file here instead for you...

http://dropcanvas.com/pu3pr

Thanks for the 1979 Service Notes.  The wave forms for Vibrato and Chorus were what I was looking for.  My amp is a later unit.   I have the1983 Service notes, which cover my unit, but have no Vibrato Osc or BBD waveforms.  I think that with the two documents I should be able to work it out.

I really need a JC-120 service manual.  I have searched online and all the standard sources have removed this document.  I an looking for some one that has this PDF file.  My Amp S/N:477562