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    Building, troubleshooting and testing of these amplifiers should only be
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help, Built from scratch Kalamazoo 2 noise

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My first tube amp build from complete scratch is a Kalamazoo 2. I picked it only because it seemed to be simple enough while still having tremolo.
the problem: a foggy ground hum (as I expected)
a screech
I used a star ground method and hit every point so I think I'm stuck with the hum. The screech though, it appears at 3/10 on the volume pot and increase in volume as I turn it up. The tone pot does eliminate it tho, if I turn the Tone down it subsides with only implied buzzing (kinda hard to explain)
I have replaced the tubes, checked all soldering/wiring, temporarily lifting the ground, and even temporarily bypassing the rectifier tube with diodes (last resort). nothing effects the screech except that tone knob.
If you could give me a clue, I'd appreciate it. If I can give you more info to help I'll post it. Thank you for your time.
Here is a link to the schem and info on it.

Kalamazoo Amp Field Guide (frames)
 
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