Author Topic: Rhodes power amp distortion, but external keyboards work fine??  (Read 152 times)

Offline nooxygen

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Rhodes power amp distortion, but external keyboards work fine??
« on: September 29, 2019, 03:43:13 PM »
My Rhodes 73 suitcase (Janus amp, 5 pin) is distorting pretty badly, almost like I'm running it through an overdrive pedal. However, when I plug an external synthesizer into the power amp input, the synthesizer doesnt sound distorted at all. I tested a few other things to try isolating the problem but I still can't figure it out:

•tested the RCA cable coming from the harp to the preamp, works as it should
•adjusted the pickup distance for all pickups and they're within recommended spec
•connected the preamp output on the power amp to my recording interface, clear signal with no distortion
•Plugged headphones in, no distortion in the headphones
•cleaned all pots and switches but that had no effect

Again, when I plug my synthesizer into the power amp input jacks (both A and B), the signal is totally clear so the speakers arent blown. And the preamp seems to be functioning as it should since there is no distortion when I listen using headphones or connect the preamp to my recording interface.

Any ideas what this might be??

Offline nooxygen

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Re: Rhodes power amp distortion, but external keyboards work fine??
« Reply #1 on: September 29, 2019, 04:35:36 PM »
Problem: SOLVED!! Turns out the molex connectors were the problem. After removing them, applying hot glue to the board, putting them back in, and then soldering each point the distortion completely went away. Here are some better explanations of my problem and how I was able to fix it:

https://ep-forum.com/smf/index.php?topic=8450.msg44725#msg44725

https://ep-forum.com/smf/index.php?topic=7916.msg41087#msg41087

Offline Alan Lenhoff

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Re: Rhodes power amp distortion, but external keyboards work fine??
« Reply #2 on: September 29, 2019, 09:41:59 PM »
Applause for solving your issue!  Those connectors seem to cause a lot of Janus Suitcase amp issues. The archives of this site are a great resource for troubleshooting.

Alan

Co-author, "Classic Keys: Keyboard Sounds That Launched Rock Music" (Coming November, 2019)

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1965 UK Vox Continental;1967 Gibson G101 organ; 1954 Hammond B2; Leslie 21H; Leslie 31H; 1974 Rhodes Mark I Stage 73; 1972 Rhodes Sparkletop Piano Bass; 1978 Hohner Clavinet D6; 1968 Hohner Pianet N II; 1966 Wurlitzer 140B; 1980 Moog Minimoog Model D; 1977 Fender Twin Reverb; Vox AC30CC2X amp.
(See the collection: https://vintagerockkeyboards.com/ )