Solid State Guitar Amp Forum | DIY Guitar Amplifiers
Solid State Amplifiers => Schematics and Layouts => Topic started by: KB0NES on May 30, 2019, 02:28:45 PM
I just pulled my 1981 Yamaha JX20 amp out of the closet for the first time in decades. Playing around with it a bit and would like to mess with the circuits a little and retro in a digital reverb etc. Looking for service docs/schematic, I've been Googel'ing for a spell and haven't got lucky yet. Found the owners manual and service docs for a JX30 & JX40 (those may be close enough).
Does anyone have a JX20 service manual or have a link to one in an archive that I haven't found yet?
Thanks,
Phil, KB0NES
Burnsville, MN
https://www.owner-manuals.com/-manuals-1-20a.html?alpha_filter_id=74 (https://www.owner-manuals.com/-manuals-1-20a.html?alpha_filter_id=74)
See YAMAHA JX20 Owner's Manual page 7 (block diagram) for the difference between amps JX20 and other JX series amps.
Already ahead of you there. I actually still have the printed manual I got when I bought the amp and I did download a PDF of it too.
A high school friend of mine had a JX30B that we added a HF horn to use for his keyboard amp. Indeed all the variants are likely very similar. If I can't find the actual manual I'm sure I can just inspect and markup the JX30 manual which is likely quite similar.
I saw on another thread where the OP was looking looking for a JX25 manual that he stated he had found one for the JX20, so they must be out there. Funny I can't dig it up with the search engines.
Phil