Any Short Path To Learning Basic Amp Repair?

soundchaser59

Thank You Great Spirit!
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I mean without having to quit my day job, won't make me move to another city for school, and won't break the bank.

I have an Associates AAS background in Electronics, so the basics would come back to me easy enough......I just haven't used it because I got into programming instead, it paid better.

But now that I'm up to my ears in buying and selling tube amps and unrelenting amp and pedal GAS.....and partly because the only tube amp whiz kid here in my town dropped dead last year from a heart attack.....I find myself wishing that I could do basic amp repair and cap jobs and tranny upgrades, etc, for my own good and to help the other players here in this area. Besides, I figure it's probably a good skill to have on the side 10 or 15 years from now when I retire.

So what's the shortest route to reach the point where I could start telling other people here in town that I can fix their amps? Are there local users groups? Correspondence? Anybody ever attended the Bruce Egnater amp building class? Is there enough resource online to let me sort of teach myself?
 

zenas

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8,866
No short cut. Lot's of reading, I've been reading tube electronics books for 20 odd years now mostly the musty smelling old books written "back in the day."

Big diffirence between repair and design. I tought myself how to repair amps starting 20 some years ago. I was married, had kids, ran a buisness and didn't have the money it takes to go from one "tech" to the next to find a good one. (most suck)
So I started reading and messing around. Old books are best and some books (old or new) are best used for leveling table legs.

Now design is a whole diffirent level and frankly I have no intrest in that anymore than I do in redesigning my car. I just want to repair the dammed thing and make it work right.

Internet forums are great of course. Just plan on snarky comments because you didn't build a time machine, go back to 1955, attend MIT and get a PHD in vacuum tube enginering.
 
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Blue Strat

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30,197
Your 2 year electronics degree should help a lot when you learn to apply what you already know.

There are a bunch of tube amp books and repair books that discuss circuit analysis. Then, get into one of your amps with a meter, signal generator and scope, and start getting your feet wet.
 

VaughnC

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18,112
With your degree, you should have a handle on electronic theory & the math behind it, and understand practical application...so, all you'd need is some decent test equipment & proper tools. Guitar amps aren't rocket science, but too many "amp repair techs" are just parts swappers that wouldn't even know how to turn on an oscilloscope, let alone use one. Start by investing a good multimeter, signal generator, oscilloscope, variable temperature soldering station, and appropriate hand tools, learn how to use them, and have at it. IMO, if you want to learn electronics the right way, there are no shortcuts. You need knowledge and the proper tools...otherwise, it will be guesswork.
 
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Diablo1

Member
Messages
620
Buy and read valve wizard's book.
Jack Darr's book is good too, and free on the web somewhere.
Read Aiken amps tech info.
That should be a good start
 

zenas

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8,866
I'm one who can't turn on an ocilloscope. (used them on cars though) I do need to get one though. I spend hours sometimes nailing down exactly which resister or coupling cap is bad before I unsolder and replace it.

By the way plenty of techs with ocilloscopes are parts changers.
A tool is only as good as the guy using it.
 

RiftAmps

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207
To supplement the reading, you could start out building yourself an amp from a kit, that way you learn a lot of the techniques as you go...

Once you've fitted 30 resistors, 20 caps, 5 valve sockets, 6 pots, 2 transformers and 2 input jacks, wired it all up and thought about each process as you go, then replacing any of those parts in a customers amp isn't a big stretch.

My first repair job was a power tube replace+bias, the second was a broken input jack and the third was a cracked valve socket. If I hadn't built a few kits for my mates beforehand, I wouldn't have been able to do those repairs confidently.

I'm not saying it's quick and easy but it really helps.
 

corn husk bag

Member
Messages
4,242
:aok
To supplement the reading, you could start out building yourself an amp from a kit, that way you learn a lot of the techniques as you go...

Once you've fitted 30 resistors, 20 caps, 5 valve sockets, 6 pots, 2 transformers and 2 input jacks, wired it all up and thought about each process as you go, then replacing any of those parts in a customers amp isn't a big stretch.

My first repair job was a power tube replace+bias, the second was a broken input jack and the third was a cracked valve socket. If I hadn't built a few kits for my mates beforehand, I wouldn't have been able to do those repairs confidently.

I'm not saying it's quick and easy but it really helps.
 

corn husk bag

Member
Messages
4,242
No short cut. Lot's of reading, I've been reading tube electronics books for 20 odd years now mostly the musty smelling old books written "back in the day."

Big diffirence between repair and design. I tought myself how to repair amps starting 20 some years ago. I was married, had kids, ran a buisness and didn't have the money it takes to go from one "tech" to the next to find a good one. (most suck)
So I started reading and messing around. Old books are best and some books (old or new) are best used for leveling table legs.

Now design is a whole diffirent level and frankly I have no intrest in that anymore than I do in redesigning my car. I just want to repair the dammed thing and make it work right.

Internet forums are great of course. Just plan on snarky comments because you didn't build a time machine, go back to 1955, attend MIT and get a PHD in vacuum tube enginering.
I have found that most of these guys give up the goods, and in the end can be helpful. You have to take the good with the snarky. If you do it without getting ruffled, some of the snark like ones can become friends!
:bonk
Kind Regards,
Steve
 

zenas

Member
Messages
8,866
Steve you are correct. I have found that to be the case in many phases of live.
The interaction between people is lacking on Internet forums so it can put a person off.
Hell I get snarky myself from time to time.

Sometimes we forget we all started from ground zero.
 

benjammin_

Member
Messages
267
Always found Gerald Weber's books to be super helpful for me, as well as just reading anything I could find. If you can find a Valve Junior cheap, it's a nice platform to start messing around--tons of mods, and way cheaper than a kit if you mess it up :]
 

jay42

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7,065
I have two suggestions:
1) identify an amplifier which is less expensive to DIY than buy an original. Source all the pieces instead of buying a kit, e.g. '57 or '59 Tweed Twin, early JTM 45 with KT-66s, etc.
2) buy an '83 Fender Concert or Twin Reverb II and make improvements
 

RocksOff

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7,457
Build an 18 watt. Easy build. However, be careful. Poking around in an amp can cook your goose. Literally.
 

ned7flat5

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4,660
Gerald Weber puts out a fairly good Basic Tube Amplifier Maintenance and Repair DVD that I've watched a few times and got a lot from. Not a dry technical publication but some great advice and insights which should give anyone (with some commonsense) enough confidence to work on their own amps to attend to most situations which emerge from time to time. I've just checked and there's even a few excerpts on Youtube.
 

zenas

Member
Messages
8,866
Building kits is great but how about buying broken amps and repairing them? Nice thing is you have a better shot of getting your money back if you sell it.
Old tube radios are fun too no money in it but fun.

Also gets you away from layouts and into schmatics. In some cases you can't even find a schmatic.
 

icr

Member
Messages
2,855
Learning basic tube amp design, function and repair is easy. The problem will be when a customer brings a modern, complex, two sided printed circuit board amplifier for repair. You either need factory specific information or lots of experience with that type amplifier.


 

soundchaser59

Thank You Great Spirit!
Gold Supporting Member
Messages
12,881
The problem will be when a customer brings a modern, complex, two sided printed circuit board amplifier for repair. You either need factory specific information or lots of experience with that type amplifier.
Which is why the amp techs here now always ask "What kind of amp is it?" They only agree if it's (1) under warranty, which likely means they will not be the one working on it, it will get shipped, or (2) it's an older hand wired amp and they know they can figure it out or they have a schem in the bottom drawer.
 






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