Silvertone Chord Organ Restoration

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Hey everyone!

My friend gave me a Silvertone Organ recently. I cannot seem to figure out which model I have and subsequently cannot locate a schematic for it. I have been building and modding amps for 12 years and used to work for a great company called Sommatone, although now I just dabble for fun.

The amp is super clean. My buddy told me he played it pretty regularly and when I played it the only bad things I could hear were a bit of hum but mostly the volume was super low. I'm only planning on replacing two of the electrolytic caps, one cap that looked like it was in rough shape and popping in a fresh set of tubes. I was surprised to find the microphone was stuffed into some foam. Is there a better way to suspend it? I have to imagine all that foam must muffle the sound a good bit. I'm definitely open to any suggestions anyone may have about any upgrades while I'm in there! I'll also be taking apart the keyboard and blowing it out with air, clean all the contacts. One of the chord keys didn't work so I'm hoping to amend that as well. I can update with progress shots if anyone is interested.

Oh, and I found this comprehensive list of Silvertone Schematics here I just need to know which model is mine!

If you can't tell by the photographs the tube layout is 5Y3GT, 6AQ5A, 12AX7, and what I believe is also a 12AX7 but is unmarked.
Sorry I couldn't figure out how to get the images to display nicely.

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Put your ear inside the reed chamber. It is very loud and shrill in there. You WANT to muffle the mike. It was voiced to work that way.

The model number is more likely stamped on the outside of the chassis.

:D I will have to take a listen when I get it back together. There is a number stamped on the chassis: 157.47211

Unfortunately googling that model number got me no further.
 
I have the exact same amplifier and I can confirm that it is *NOT* a model 4784. There's an extra 10MFD power filter cap that the 4784 doesn't have, and I'm not sure about yours, but on mine the first half of the first 12AX7 isn't even connected. Nothing soldered to lugs 1,2 or 3.

Any luck tracking down a schematic? I have the same chassis number, 157.42711 and did manage to track down a schematic for the model 4784, but that's not what we have here. That model is chassis number 157.10000. Looks identical from the outside though.

I'm going to try and re-draw the schematic at some point this weekend.
 
I was going to suggest drawing out the schematic using the parts, Not a whole lot there. Just took apart a few 'tone boards' from a Wurlitzer, real point to point with a wire grid up in the air. Not my picture, was glad someone to a picture of it, nothing was coming up for a while in my search.


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