This one's a bit above my semi-novice troubleshooting. Recently picked up a second Optigan on the cheap and all about it is a dream except crackly distortion, mostly prominent all the left channel chord buttons. I bought a new speaker and installed it, thinking that was the primary issue. But alas, the speaker is not the issue, I still have distortion on the left side. Using the Bossa Nova Style disc to test the full range of effects, the Special Effects buttons (4 & 5) that feature drums are bass distorted. 1-3 SE switches are fine in tone.

When I play the O with headphones in, there is absolutely no distortion on the left side, all is flawless, both SE switches and chord buttons. The wires running from the left speaker appear in tact- both to the amp and to the headphone jack. I even tried to run a left-right splitter adapter from the Optigan into my Presonus firebox. The keyboard side sounds great. The left side, faint and just not there.

Any input waaay appreciated.