How did you get started building/fixing/modifying guitar amplifiers?

[RWood]

I've always been curious about how things work, something that we all might have in common. In 1969 when I was eleven, I had been playing guitar for three years and really thought I was up on the Top 40 world - I knew every song. Then my uncle gave me an FM radio, a Grundig table model, and my little world changed forever. The advent of underground radio (for me, WDAS in Philadelphia) was an ocean of new and different sounds and styles. And the fidelity blew my mind! But of course I had to try to improve on it, so I started plugging speaker wires from the radio into my Silvertone guitar amp (...whoa, that's loud!) and began hooking up various speakers around my bedroom (for stereo, don'tcha know). I screwed up the dial string on that Grundig and could then only get stations on the low end of the scale, so WXPN began to make a strong impression on me (anyone remember Michael Tearson?).

I was very lucky to have a buddy across the street who also played guitar and had the attitude of "let's just build what we need". Seems like we were always building little boxes with jacks in them to plug our guitars into radios, into phonographs, etc. I recently discovered that my family's Motorola record player from the 60's had the exact same tube complement as a Marshall 1974. Sorry to say my version didn't sound quite as good.

It was all very naive stuff and very basic in retrospect, but it was a healthy outlook and there was no fear of opening something up. It was really just word of mouth when, say, "my Dynaco power amp hums, what do I do? Lets change this big capacitor" or "my Twin stopped working...somebody said to check the screen resistors". I probably learned the hard way, like recapping an entire Ampeg just to fix a tremolo who's ground wire came undone, but aren't those the most lasting lessons?

I'll close by saying that for me, it was the internet (specifically sites like this one) that alowed me to start to understand what I was doing. I consider tube amps to be a limitless well of ideas and possibilities....and sounds. Kinda like what I felt about music when I found FM!

[Prairie Dawg]

I don't know about anyone else but I learn far more from my failures and struggles than my successes. When you have to get serious about figuring out how and why something works and why what you did to it didn't help or made things worse, that's when the bull pucky stops and the learning begins. One thing I have carried across from my years as an aircraft engine mechanic is to never get yourself in a situation you can't back out of. Always leave a trail of breadcrumbs and use that digital camera. Make shop drawings as you go. Put tags on loose wires. Relying on memory is a sucker's road.

[HTH]

I would always open up amps and effects pedals, I was intrigued by this stuff from my teens. I started off with changing pickups and doing some wiring mods on a Strat, then bought one of those 'Penfold' effects pedal books around the mid 90s. This eventually led to me making an EH Muff Fuzz clone and a silicon Fuzz Face from Justin Philpott's site (and some reading on RG's Geofex site). I subsequently made loads of vintage fuzz circuits - anything that was out there with a schematic available.

The change-over into amps came when I took two amps in for biasing (around 1999/2000) and they came back sounding gutless (cold bias) - plus the guy royally ripped me off for the work. I studied the schematics and worked on my two amps (a Tonemaster and a Bluesbreaker) eventually modding them to taste and learning how to bias them up. I caught the amp bug in a big way and never looked back.

[soundguruman]

It sounds as if you are more than sufficiently deranged, to be working on sound equipment.
It takes a certain type of person to do that. Not for everybody, as glamorous as it may sound,
it's actually something that takes a great deal of practice and patience.

[Chuck H]

it's actually something that takes a great deal of practice and patience.

And shocking the $h!t outta yourself at least once, several clumbsy soldering iron burns on both you and your table (that you should have put something down on), many blown up components and tubes, loads of builds that need to be rebuilt to newly realized construction standards and the ability to live on toast and coffee for up to a week at a time.

Oh... It also helps if you border on insane.

[soundguruman]

And shocking the $h!t outta yourself at least once, several clumbsy soldering iron burns on both you and your table (that you should have put something down on), many blown up components and tubes, loads of builds that need to be rebuilt to newly realized construction standards and the ability to live on toast and coffee for up to a week at a time.

Oh... It also helps if you border on insane.

Shocking the crap outta myself? I'm used to it, how do you think my hair got so curly?
I bought a soldering station that turns itself off, so I wouldn't burn the house down.
I give the blown up parts to the customers now, it helps decrease the shock and awe of the repair bill.
And the sale of $1 burritos has increased, for some reason (?) locally.
The guy who owns the local music store.....where I drop the repairs off.....is crazier than I am.
That's not ......good.

[jamesmafyew]

It's weird, I got started on amps because of this forum. I think I'm younger than the median of posters here (28). That's why it's so great; other forums are filled with 16-year-olds and all this absurd misinformation like "kinkless tetrode means that it's not mid-scooped." I've never posted that much here but I've spent countless hours reading threads over many years now.

I got started when I figured out how to install guitar pickups when I was 15 and had rock star ambitions. Later on I was broke but wanted better tone, so I stumbled on to this forum looking for tips for modding my Marshall. That's what got it going. I ended up touring around the country and needed to learn how to do basic repairs on my gear while on the road... searched this forum over and over.

Now I'm doing music/touring enough that I need a flexible day job... and fixing people's amps turned out to be the best way to do that. I never intended to be an entrepreneur or anything, I'm just doing work that I now know how to do -- mostly because of hunting through this forum and paying attention when the more experienced people post. I'm not really an autodidact, I guess you could say the "forum taught me" and now I'm actually making a basic living off of doing the work. Most repairs are easy. I like the hard ones better though, because I like solving puzzles and being forced to learn.

Has anyone here read the book Shopclass as Soulcraft by Matthew Crawford? It's an argument that handiwork has a higher level of intrinsic satisfaction than "knowledge work". The author is a philosophy PhD who started a motorcycle repair shop. The topic seems pretty relevant to why so many people get into this.

[Chuck H]

It's an argument that handiwork has a higher level of intrinsic satisfaction than "knowledge work". The author is a philosophy PhD who started a motorcycle repair shop. The topic seems pretty relevant to why so many people get into this.

I haven't read it... Yet...

I think a big part of the appeal is that this is an art that isn't now, nor has ever been taught. AFAIK there has never been a course on how to make tube amps distort in a pleasant and musical way to be used as an instrument unto itself. Obviously thier use is most important for electric guitars. There's a certain type of person that pursues things because the knowledge base is so bare that they can learn as much by doing as they can by reading. I do it for some of the same reasons I fish. I want to see what CAN happen as much as what does happen. Amp design and fishing also share the aspect of being a series of perpetual occasions to "hope". I wouldn't be at all surprised to learn that a disproportionate number of posters here are also fishermen.

[Gingertube]

I actually came at this from the HiFi end. I am an Electronic Design Engineer in the day job. I got to that the "hard" way, Apprenticeship, Technical Assistant, Technical Officer, Junior Eng, Senior Eng with lots of night school along the way.
I love my music, all sorts classical to heavy metal. I designed an built a number of HiFi Amps until I got to the stage were someone told me that if you really want stunning music then you should be using a tube amp.
So I built one, from someone elses design and it was glorious - never had a SS Amp in the HIFI System since but instead a succesion of own designed tube amps each new one exploring new insights and merging some modern SS techniques into the tube amp designs. You can see my "Baby Huey" design over at DIYAudio. The thread runs 80 odd pages and there have been around 50 of these built by various folk around the world.
Since I had good technical knowledge of tubes, was set up with oscilloscope, signal generator, Tube tester etc. someone asked me to do a repair on a Fender Twin Reverb, When he got it back he claimed it had'nt sounded that good when he bought it new. Things snowballed from there getting amps referred to me by word of mouth until around 3 years back I had a commission from a friend to design and build him the "ultimate" tube guitar amp - money no object, at which time I started looking at guitar amp design more seriously. His Amp (I did'nt tell him so) was another experiment investigating the use of parallel output tubes, since he did'nt need huge power, it ran a quad of 6V6 into a 50W Marshall Output Transformer. It also boasted 2 channnels footswitchable, tube driven reverb and recovery (3 spring long delay tank) , full tube effects loop, balanced line out, Power Scaling, switchable cathode/fixed bias triode/pentode mode on each output pair etc. He loved it, I thought it was really good but too many "bells and whistles".

The weird thing about this hobby is the things which can happen without you really working at it. The local "Guitar God" now brings me all his amps. He noted an old amp stuck in a corner at my place and asked to borrow it to check it out. He now won't give it back. That was an ex PA Amplifier that I did a quick and nasty mod/rebuild on one Sunday afternoon just so I would have an amp to run my new Nylon String with Pickup Yamaha Guitar into. I left the power supply alone (except for new caps), left the cathode biased EL34 Output Stage (35 Watts), replaced the 70V Line Output Tranny with another spare 50W Marshall Tranny and just redid the preamp to a Tranwreck circuit which is pretty much your standard Fender BF with an extra gain stage stuck on the end. This is the one amp I spent the least time and practicaly no new design effort on and yet it is the amp the best professional guitarist I know now uses for all his gigs.

Is any of this useful in the dayb job - surprisingly yes, I'm the Senior design Engineer for a Laser Airborne Depth Sounder System, the main Laser Receiver uses Photopmultiplier Tube, understanding how this works has allowed me to implement a tricky gain control circuit using the tube itself rather than rely on the "usual" method of running the photomultiplier tube into a logarithmic amplifier. That one little "secret" is why (well one reason why) our system out performs all its competition.

So (since I have access to "flash" tools etc) do I use modelling - Generally No, the only decent model of a vacuum tube is a vaccum tube, you have to build it and listen to it. I do occassionally use PSUDII, B2Spice and similar to set intial design but regardless of how much you spend the the ultimate bit of test equipment will always be your ears (aided by whats between them of-course).

Biggest Hint: The Speaker(s) you use will always account for 50% of your final sound, don't skimp on the speakers.

Fishermen ???? (See post above) - Not me, I'm in the Aussie school of:
- any fishing trip is a success as long as you don't run out of beer
- the only thing with wrong with going fishing is that there is always some silly bugger who wants to fish.

Cheers,
Ian

[Chuck H]

Is any of this useful in the dayb job - surprisingly yes, I'm the Senior design Engineer for a Laser Airborne Depth Sounder System, the main Laser Receiver uses Photopmultiplier Tube, understanding how this works has allowed me to implement a tricky gain control circuit using the tube itself rather than rely on the "usual" method of running the photomultiplier tube into a logarithmic amplifier. That one little "secret" is why (well one reason why) our system out performs all its competition.

Awsome. The idea that learning the compression and self limiting effect of tubes improved on current technologies tickles me where it counts. Proving that there is no limit to what we haven't learned yet.

Fishermen ???? (See post above) - Not me, I'm in the Aussie school of:
- any fishing trip is a success as long as you don't run out of beer
- the only thing with wrong with going fishing is that there is always some silly bugger who wants to fish.

I dunno... Tempting the abyss with a hook and coming up with food is not at all unlike using peripheral technology to find unpresidented results. Perhaps you should try fishing again. You may find that with a little consideration "fishing" can turn into "catching" which is emminently more satisfying.

[GregS]

Has anyone here read the book Shopclass as Soulcraft by Matthew Crawford? It's an argument that handiwork has a higher level of intrinsic satisfaction than "knowledge work". The author is a philosophy PhD who started a motorcycle repair shop. The topic seems pretty relevant to why so many people get into this.

For me handiwork is definitely more satisfying whether it's building amps, decks, sheds etc. Perhaps it has to do with creating something that's physically real.

I wouldn't be at all surprised to learn that a disproportionate number of posters here are also fishermen.

I also fish so there's some more support for your theory.

Greg

[jamesmafyew]

For me handiwork is definitely more satisfying whether it's building amps, decks, sheds etc. Perhaps it has to do with creating something that's physically real.

Crawford argues that knowledge work requires the worker to constantly interpret his work for other people -- explain why it's valuable, necessary, good, etc. Manual work is self-interpreting; i.e., the thing works or it doesn't. It speaks for itself. I find I'm less anxious about the products of my labor now than when I worked a desk after college. I'm also pretty proud of my workmanship in a way I never was when I was creating pamphlets and reports.

On the other hand, I think it makes for a temptation (for me at least) to get into a know-it-all mindset. I've learned a lot from people like Enzo on this forum who have consistently emphasized the need to treat all clients with respect and decency regardless of what they're bringing in.

[jmaf]

Crawford argues that knowledge work requires the worker to constantly interpret his work for other people -- explain why it's valuable, necessary, good, etc. Manual work is self-interpreting; i.e., the thing works or it doesn't. It speaks for itself.

I had never heard it put this way, and IMO you're absolutely right (Edit: I just reread and noticed you quoted someone, thanks for sharing that.).

I work with computers nowadays(who doesn't...) and when there's a family meeting or with friends I always need to "explain once more" what I do. And in the end, I always get this feeling it's as if I hadn't explained at all.

Yet, when an amplifier is sitting on a desk and folks come to visit and they see it, they say "hey this thing looks like an old TV set, it has tubes"...then someone will tell the visitor "he built it out in his garage"...the reaction is always the same. Sufice to say, the amp, built and sitting there, is self explaining.

[schraedertr]

I was born with the "Let's take it apart and see how it works" gene, and regularly got into trouble for taking things apart that didn't need it. I grew up in Iowa, and spent time at the blacksmith's shop looking how one motor with a line shaft ran everything from a band saw to a Little Giant trip hammer. Fortunately, my father ran his own business and so I learned to wire houses and do plumbing and heating, but mostly run a shovel. I managed to save enough for a year of college and was pretty put out when the intro to electrical engineering course instructor told us we weren't there to learn how to fix TVs but to learn how to design them. I'd already come to the conclusion that there were too many things poorly designed by people who didn't have to fix them.

Ran out of money, went back to being an electrician, got married, moved to Morocco and taught electrical construction in the Peace Corps. Much like Columbus heading West to get to the East, we decided to get rich by going through poverty. It worked, I had made too much money working to qualify for college loans or grants, but the time in the Peace Corps did wonders for loan qualification. I went back to college and did the Co-op program in electrical engineering. I co-oped with an architectural/engineering design firm and took all electronics courses. I was going to get a job, no matter what.

I sold my Dynaco tube stereo and my Vibrochamp along with a Gibson lap steel to get through the last semester of colllege. I had gotten hooked on motorcycles overseas and spent a long time rebuilding Triumphs, BSAs and Nortons. I really didn't play for years, until my oldest son became interested in bass.

I found out about the Musician's Friend outlet store in Kansas City and bought him a bass and an amp there. One other day I stopped in and they had their house brand (Rogue) 20 watt bass amps stacked about 10 deep by the door, your choice for $3. I bought 5. Over then next 5 years I bought over 600 amps from them. There were a lot of us very sad when they closed the outlet store at the end of 2009. The amp money bought a lot of nice guitar stuff.

I still maintain the amps for 2 high school jazz bands, talk about a tough testing environment. I'm doing more tube amp stuff now, but it's just a hobby. I'm about ready to build a tube amp from scratch, but I've got a couple of guitar builds to finish first. I'm always intriqued by how ideas from one field transfer into others, and I've learned a lot about troubleshooting from this forum. I also remember reading in Click and Clack's Rants and Raves that most of the math we learn is simply so we can learn more math and that the world would be better off if we studied decision trees.

Thanks for the help everyone, especially Enzo.

[Prairie Dawg]

Y'know this thread has got me thinking about something called Bloom's taxonomy of learning, which one of the schools I taught for was obsessed with. The idea is that there are different levels of learning from the least to the greatest: knowlege, comprehension, application, analysis, synthesis, and finally evaluation. They also were obsessed with methods of learning-visual, auditory, and so on.

One of the things that they never mentioned in faculty meetings was something that I know exists, and that is tactile learning-that is, learning by how things feel in your hands or appear to your senses. It is related to kinesthesic learning but you have to recognize that it's there. When I'd mention this they'd look at me like I had three heads, but I can tell you, having spent 12 solid years on the flight line, that's one way I learn. What was wrong with those folks was they'd never had a job working with their hands and had no frame of reference for it.

What does this have to do with amps, you ask? Simple. There is no one best way of learning-that is mere Taylorism, and unfortunately that is what they often teach in the universities because that is all they know. When you consider the complexity and power of the human mind coupled with the eyes, ears, hands and senses, it's really silly to think that there is only one valid way to learn and to master a discipline. On the other hand it is impossible to argue with people who know they've got the inside track-they don't much like heretics.