Help! Damn leslie

jrmintz · Jul 20, 2005

Hey all,

I'm in the middle of a record and the f*cking leslie 122A stopped switching between fast and slow - it's stuck on slow. It's not the switch or the cable, and Goff is closed til August. Does anyone know what could do that? I heard one of the tubes in the Leslie amp controls the speed relay, but that if it were bad the Leslie would be on fast. I'm at the studio and my schemos are at home. Anybody? It's a 122A - did I say that?

Thanks - I'm flipping out. I really need the thing to work.

cayocosta · Jul 20, 2005

http://www.hammondb3organ.net/schematics/leslie/122/122.GIF

cayocosta · Jul 20, 2005

Good troubleshooting thread:

http://groups-beta.google.com/group/alt.music.hammond-organ/browse_thread/thread/20dd6af99a74a1f8/263beaace4375ff9

jrmintz · Jul 20, 2005

Thanks Ron. I'm going to do some reading and see if I can figure out what's up.

NewYorkDave · Jul 21, 2005

Once you have the problem sorted, it wouldn't be a bad idea to add a flyback shunt diode across the relay coil. The flyback when the coil is deenergized (when the 12AU7 is in cutoff) is hard on the tube. C4 looks like a potential source of failure also.

jrmintz · Jul 21, 2005

Thanks for your help Dave. It was almost certainly a bad tube. I'm only uncertain because I also seated and reseated all of the tubes and five or six molex connectors, some of which looked suspiciously dirty. Thankfully we got it working today and finished the rhythm tracks. This Leslie is also a 122A, which has a different motor control layout than the 122. I haven't been able to find a schemo online.