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Tips on tuning up an Ampeg VT-22

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4/10/2000 3:14 AM

Tips on tuning up an Ampeg VT-22

A buddy gave me a mid 70's Ampeg VT-22 to
tune up. It's pretty dusty, apparently
hasn't been used for quite some time.
One of the 7027s in it looked real frosty
and the bulb actually broke off in my hand
when I tried to pull it out.

I plan to replace all the electrolytics.
Then install some Svet 6L6's in place of
the 7027's as per Ned at Triod.
Make sure all the switches and jacks do
what they should. There's no bias control
but there is a hum balance control.

My question is is there anything else I should
do to this amp to tune it up. And how
to adjust the hum balance control. I
did get a schematic from the web.

Thanks,
jc

4/11/2000 12:55 AM
Randy Jamz	The hum balance control is used to attempt to balance the 6.3VAC winding. Turn the amplifier on and up, and adjust the control for the least amount of hum. Simple. I would scope out your output tubes and make sure the 6L6's are biased right. You should check plate current to be sure you don't exceed plate dissipation. After that you should be fine.

4/12/2000 3:42 PM
jc	Randy, Thanks jc

4/13/2000 4:33 AM
Richie	Alot of ampegs i have gone through. have resistors way off tolerence. Be sure to check these and replace if you need to. Can make the amp sound better. And that hum balance pot is usually kinda cheesy in these. So either add just the resistors,and remove the pot or put in a better pot. {~}==::: Richie

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