I've got this client who plays guitar and keys, and he bought a passive Leslie to go with his M110 Hammond. He got a Leslie 25 amp off ebay, and he wants me to mod it to take either guitar or organ.
So my plan is to install one more tube, a 12AX7, and add vol/treb/bass controls. It'll have a jack before the 12AX7 for guitar, and a switched jack after it for the organ input.
As you can see by the schematic, it's an odd duck of a booster amp. It's got 6L6 tubes, but is dialed way back to make only about 20 watts.
If you look closely at the schematic, you'll also notice a balanced output transformer design, which has a center tapped secondary. I've never seen this before, and I was wondering if anyone on TAG understood these in depth. In particular, I'm curious of the impedance relationship here. If I lift the CT, how does that affect the reflected impedance? What about the power handling of the OT?
Any ideas?
Leslie 25 amp project
Moderators: pompeiisneaks, Colossal
Leslie 25 amp project
You do not have the required permissions to view the files attached to this post.
Rich Gordon
www.myspace.com/bigboyamplifiers
"The takers get the honey, the givers get the blues." --Robin Trower
www.myspace.com/bigboyamplifiers
"The takers get the honey, the givers get the blues." --Robin Trower
-
Cliff Schecht
- Posts: 2629
- Joined: Wed Dec 30, 2009 7:32 am
- Location: Austin
- Contact:
Re: Leslie 25 amp project
Hrmm.. Might be to intentionally cause a 180 degree phase shift between two or more speakers. Or might be 4 Ohms on one side and 8 Ohms on the other. I've never seen that done before though..
Cliff Schecht - Circuit P.I.