Some one gave me parts from an old Leslie 122 ?? guitar amp maybe

[copperheadroads]

Someone brought this here instead of bringing it to the dump & asked if it was any good to me ,
they scraped the Leslie & kept the cab
so i ended up the chassis & reverb plus the motors .
Any way ,any one ever build an amp for guitar out of one ? it has 2 6550 's

[The Dude]

The schematics are here. One for the reverb amp and one for the main amp

Hammond-Leslie FAQ - Schematics

Lots of possibilities there, but you've got enough to start 2 amp projects. Good score!

[copperheadroads]

I'm thinking i need new bigger chassis to redo these in to guitar circuits as they are pretty compact & is there any benefits of using the OC3 voltage regulator tube or should i ditch it or put it on a switch ?

[The Dude]

You could go any way you want, of course, in regards to the OC3. You can still find them on eBay relatively cheap. The regulator tube was more important for an organ given the wider range of frequencies and more program information to cause breakup and sag. There would be little sag with a regulator tube. So, it depends on what kind of sound you're looking for. If you want sag, I'd get rid of it and create another supply node with resistor/cap combination. If you want less sag, but don't want to mess with the oddball tube, maybe go with zener(s). You could just leave it as is. Lots of ways to go.

[copperheadroads]

I've started gutting out some of the things for this conversion ,
I intend to use these tranny's,choke & chassis & keep the rectifier intact as is , probably ditch the 0C3
I'm not sure what exactly i'm building yet but something along the line of an amp with some breakup to it ,possibly jcm or something with simpler controls . & a master volume
the heater windings of the PT puts out 3.8A /6.3V so if i go with two 5881's It would power three 12ax7's but it's gonna be a pretty tight squeeze to get it all in there .
some sort of Supro/Valco type amp would be cool ,but I couldn't find much in schematics that is similar to what i'm trying to do here . I'm open to suggestions . Thanks .

[copperheadroads]

I also notice the output transformer is larger than the Power transformer .

[olddawg]

Since you are gutting it anyway... I would consider using a standardized chassis, new tube sockets, and all new components. You have the expensive stuff. You will have to buy pots, jacks etc anyway. Its not that expensive to start with a new, more conventional layout with more room. New ceramic tube sockets are only a few dollars. It could save you a lot of time and grief in the long by run.

[copperheadroads]

Since you are gutting it anyway... I would consider using a standardized chassis, new tube sockets, and all new components.

I do have 16" aluminum Hammond chassis here so I think i will go that route . also all the trannys are mounted through the chassis & i would rather have them sitting on top ,is there some sort way of doing that with a bracket or something ?

[olddawg]

I do have 16" aluminum Hammond chassis here so I think i will go that route . also all the trannys are mounted through the chassis & i would rather have them sitting on top ,is there some sort way of doing that with a bracket or something ?

Probably could used some 1" angle stock. Be careful with your orientation.

[copperheadroads]

Probably could used some 1" angle stock. Be careful with your orientation.

That's what i was thinking .I have a bunch of them here & i may paint the trannys & check if they need some TLC if the hum/buzz, I may have tocheck the laminates .
For now i do think i will build this with the Trainwreck express circuit in mind.

[copperheadroads]

So this Leslie main amp trannys are rehoused in an Hammond chassis to build a Train Wreck express circuit . my question is this . the leslie power tranny has no center tap for the high voltage, i have the original diodes/full wave bridge rectifier with the 8 ohm 5 watt resistor (R45) between the bridge & the PT . What else do i need to do for this build ? . I understand the virtual center tap for the heaters . but i concern about the full wave bridge compared to half wave or if my build has a center tap

[loudthud]

Just use the full wave bridge like the old Leslie. Problem is the bias supply circuit from the Express won't work. Look around at some Marshall 100W schematics that use a full wave bridge. It'll have a capacitor connected to HV winding.

[copperheadroads]

Just use the full wave bridge like the old Leslie. Problem is the bias supply circuit from the Express won't work. Look around at some Marshall 100W schematics that use a full wave bridge. It'll have a capacitor connected to HV winding.

Like this

[loudthud]

That will probably work. You have to limit the filter caps to about 10uF, otherwise they take too long to charge up. The 0.047uF needs to be 600V or higher. Make sure it works before you try it with the tubes plugged in. Also it will have problems if you switch from 60Hz to 50Hz.

[copperheadroads]

That will probably work. You have to limit the filter caps to about 10uF, otherwise they take too long to charge up. The 0.047uF needs to be 600V or higher. Make sure it works before you try it with the tubes plugged in. Also it will have problems if you switch from 60Hz to 50Hz.

Let me know if you have a better schematic to follow .