Leslie Combo Preamp Power Transformer gone missing

[jrcreative]

I got a great deal on a Leslie combo preamp and then realized why... the power transformer was missing. I'm looking for a power transformer with 34VAC output and it's apparently not a thing people have around anymore. I reached out to Jameco to see if they had something that would work in its place and they sent me here. The manual (page attached) says it's a TI Power Transformer 020446 which gives me nothing helpful in a google search. Any thoughts on what could replace it? I don't care so much about keeping it stock, so if the circuit can handle a different output voltage that's more commonly available, I'm happy to use that. If it requires custom winding a transformer I'm not sure it's worth it.

 

[dmp]

It is filtered to 48v DC then down to 40v for the preamp, I believe (posting the schematic would have been helpful). You could get this to work with other vac transformers.
The physical constraint on it might be more tricky.

 

[jrcreative]

yeah, here's the circuit, and you're correct. It's filtered to 48vDC, and then 40vDC.

Any recommendation on a replacement would be much appreciated. I think there's enough room in the chasis to accommodate a larger transformer depending on how much larger. Would it be able to generate enough volume to power the Leslie Amp if I were to replace it with a 24VAC transformer? Those are easy to find.

 

[dmp]

You could probably adapt it to use a 24vac transformer if you make it a full wave rectifier. (Add a diode bridge. )

 

[Brian Roth]

Combo preamp,,,,a blast from the past 50+ years ago in my garage band and music store service dept. days! In decades past, a Hammond Organ dealer and/or a music store selling Leslies would be a likely source, but alas.....

I found a couple of Youtube videos showing the guts. One was for a 230VAC version, and the part number stamped on it matches the service docs. It is an open frame package. . The other video shows a 120VAC version, but that transformer has metal end bells and I can't seem to read the part number.

I see some 34ish Volt possibilities in the Hammond Mfg. (NOT Hammond Organ) transformer catalog....assuming they will fit. The first thing is measure the hole spacing for the two mounting holes.

Can't link directly. Search Youtube:

Leslie Combo Preamp Inside for 147 230V Version Circuit Breaker Overload Protector Switch​

Other link:



Bri