DIY tube amp primer

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standup
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DIY tube amp primer

Post by standup » Thu Nov 12, 2015 7:41 am

I'm looking at Amazon, and there are dozens of books on tube amp repair. Who has a favorite for a beginner?

I know amp work can be dangerous, so I want to do some reading before attempting anything.

I just picked up an Ampeg Jet 12b amp. It was made in '61, and the tubes are 6V6 and 6SL7, all of which are still available.

Right now it's very quiet, the tremolo doesn't work at all, and the tone control does nothing except in the last 1/8 of the turning radius in the "Dark" direction.

Speaker and tubes look very old, might be original. I dropped a pair of 6v6 in last night, and that didn't change anything.

The circuit looks relatively simple, maybe a dozen capacitors and a dozen resistors.

My soldering skills -- I've mostly worked on guitar electronics and built cables, and built a lunchbox power supply from a kit. With the Jet I'd be replacing caps and resistors with components matching the spec, not modifying anything.

Recommendations, especially a decent book that will help clarify things? Even if the recommendation is "don't go there"...

kslight
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Post by kslight » Thu Nov 12, 2015 8:41 am

Maybe you have a cool tech in your area (like me) that is relatively cheap and will let you watch them work? At least for me, I don't learn with books, but if I do it firsthand I understand it a lot better.

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floid
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Post by floid » Thu Nov 12, 2015 9:42 am

The UncleDoug channel on YouTube has lots of good info.
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vvv
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Post by vvv » Thu Nov 12, 2015 11:02 am

FWIW, I hadda 1960 Rickenbacker M8E stop working on me.

I took my time and kinda just figured out the circuit, notice a fried cap and that the output tranny smoked.

Replaced those and it went fine - but just a simple Champ-type circuit.

You oughta hear it thru a 2x12" on "Down By the River" or early Zep ...
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Drone
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Post by Drone » Thu Nov 12, 2015 11:58 am

If you already know electronics, Google Jack Darr's book, it's usually downloadable for free from someplace.

http://www.trinityamps.com/ForumGallery ... ndbook.pdf

If you don't know electronics, get Tom Mitchell's book on the subject.

http://www.amazon.com/How-Service-Your- ... 0962817007
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standup
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Post by standup » Mon Nov 16, 2015 9:00 am

Thanks for the replies. I took the amp to a place that specializes in tube amps, much faster than mucking around myself.

The Mitchell book has a gated awful cover illustration, I would have passed that one over. Ordering it this week, might as we'll earn something after all these years, if not to fix this little Ampeg amp

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