Line out from tube organ

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OK, at long last, here is a sample of the Conn 427: Conn 427M sample 1 at Home on Saturday evening by Revolution Eagle on SoundCloud - Create, record and share your sounds for free

This is a recording from my iPad, so the distortion is the iPad's mic breaking up rather than the organ's speakers breaking up.

The tune is Agincourt Carol (pronounced A-jhin-CORE), a midieval celebratory song from England. It is sung to the words "Our King Went Forth to Normandy", as well as to the hymn "O Love, How Deep".
 
per the picture above the power supply vertical can cap has blue writing, not stamping, so it is not fifty years old. Could be recent depending on the date YYWW. The organ is so old there are probably only one or two more electrolytics. To concur in one thing, paper caps don't need replacing unless debug proves them bad. To concur in another thing,on a poorly working device I replace at most two parts at a time between function tests, to make sure I didn't make a cold solder joint or otherwise make things worse. Easy to back out that way.

Well, the can cap has a Conn parts number on it, so it can't be newer than the 80s. Also, I took a look inside the amp and found just what I was looking for: three big paper-wrapped electrolytic caps (with the clearly marked + and —) that are obviously original. Those will have to go.
 
OK, so there is something goofy in the amp itself. If you haven't already done so a fairly comprehensive recap is in order to avoid letting out the magic smoke. It is possible that just doing that might solve the oddities.

I think you are going to enjoy this piece.

Oh, wait. The pedal definitely should be controlling the volume. Have a look at the pedal and see if it has pots (potentiometers) on it or if it is a capacitive or optical type. If you are going to play music with this thing the expression pedal needs to work properly.

OK, found the pedal problem! Turns out, when I unplugged the 12" I could hear the pedal still working perfectly with the 5.25", controlling swell like nobody's business. So apparently the problem lies all on the side of the 12" (I'll assume it's either the pot or the resistor).

Also, the 5.25" must have its own tremolo separate from the rest of the organ, which would explain both the regular clicking and those three other wires running into it.
 
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