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Baldwin organ model 5A tube amps to rebuild for home hi-fi use

M

mike kelley

Member
I was able to pick these up for a song. I have two of each. They came out of a sort of working Baldwin 5a organ. Sort of working as in the tubes all fired up but the volume was exceptionally low.

Now what I would like to do is convert them over to home hi-fi use. Not sure what I have but I would like to use the smaller two as mono amps for my home system and get suggestions on the best uses for the larger ones.
My abilities include soldering and limited use of a multi meter and even more limited use of a scope. Some schematic reading. Hope this helps.

I’ve been reading the forum for a long time getting help with all the other piece of vintage equipment I have and would like to be able to start a thread where I go through the process, step by step and document it all
 

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Hopefully you have the schematics. How were the amps wired for the organ?
 
Thats some beautiful iron to play with there.
Dual 5u4 rectifier suggests lots of b+ current available probably half an amp or so. I could see you pulling 50 or 60 watts easily. Are you planning to use original output transformers or do you have something clever up your sleeve? Officially following...
 
Tinkerbelle said:
Hopefully you have the schematics. How were the amps wired for the organ?
Click to expand...
I have the original wires from the organ. I was the one who took it apart. Not sure what you mean. should I draw a wiring diagram.? I can also wire it together and upload a picture.
I may have the schematics for the amps. I've down loaded every one I could find.
 
trainbuftony said:
Thats some beautiful iron to play with there.
Dual 5u4 rectifier suggests lots of b+ current available probably half an amp or so. I could see you pulling 50 or 60 watts easily. Are you planning to use original output transformers or do you have something clever up your sleeve? Officially following...
Click to expand...
Thanks for the info. I'm planning on using as much of the original amps as i can. Always looking for advice and suggestions. Do you know if the smaller amp has a model number?
 
All 4 amplifiers came from same organ?
Looks like they split frequencies between amplifiers. Ones with smaller output transformers will be for High - Mid frequencies and ones with larger OPT for Bass
 
The Chora Tone section was a Chorus effect amplifier used to create a chorus type sound out of an organ. It does have about a 20 watt output.
 
The amps using four 6L6GC's are considered 40 watt. These one's are full range and the smaller transformer underneath is a choke. I don't know the other amps but two 6L6GC's in push pull are usually good for 20 - 25 watts.
 
grindfix said:
All 4 amplifiers came from same organ?
Looks like they split frequencies between amplifiers. Ones with smaller output transformers will be for High - Mid frequencies and ones with larger OPT for Bass
Click to expand...
All four amps came from the same organ. It had two tone box speakers with two woofers and a smaller full range speaker. they stood 6 ft tall and that is where the two different amps were located. one of each in aech box.
 
mike kelley said:
Can that be used as an audio amp for home speakers?
Click to expand...

It is an odd design that has circuits built in to create oscillations using the smaller tubes for effects before it reaches the large amplifier section. the effects section can be
disabled to utilize just the amp section if one has the schematic.
 
Dennis Gardner said:
It is an odd design that has circuits built in to create oscillations using the smaller tubes for effects before it reaches the large amplifier section. the effects section can be
disabled to utilize just the amp section if one has the schematic.
Click to expand...

Thanks Dennis. Ill probably just list those on ebay.
The smaller ones I would like to convert to mono home use.
 
I took a look on ebay. The same amp that you have is being sold as a stereo model. They are using the pedal and main speaker outputs as separate left and right.
 
Last edited by a moderator:
No, those are not field coil speakers. Generally the organ amps for field coil speakers look much older than the ones in the picture, and use stuff like 2A3s.
 
I have a Wurlitzer organ amp that uses 6L6's and has a field coil speaker. A lot of Hammond tone cabinets used field coil speakers with 6V6 tubes.

Those are some good speakers and would have some good kick with those amps.
 
century tek said:
I have a Wurlitzer organ amp that uses 6L6's and has a field coil speaker. A lot of Hammond tone cabinets used field coil speakers with 6V6 tubes.

Those are some good speakers and would have some good kick with those amps.
Click to expand...
Unfortunately they were all bad. Brittle cones and when i tried to test one of them, I blew the amp. Dead short.
 
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