Where did you learn electronics? (Amps)

Discussion in 'Amp Tech Center' started by Fretting out, Feb 7, 2020.

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  1. willie

    willie TDPRI Member

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    Back in the 50's I began a fascination with radio. In 1962 I began studying for my first FCC amateur radio license and took some basic electronics classes at a local radio club. I studied radio electronics manuals and handbooks and sat for and passed two FCC license exams. I was already playing guitar a bit and began working on guitar amps for friends and friends of friends. In the 1964 I got a job working after school working in a TV repair shop. The old TV bench jockeys didn't like working on stereo, hi fi or guitar amps, so I got to work on those...plus I got to sweep the place out too. I continued learning about vacuum tube theory and associated circuits and got some more training while in the USAF as well as taking college courses in both electronics and solid state physics. I kept studying through the years (passed another FCC ham exam) keeping up with the "state of the art" and finally ended up owning a music store and service center after I retired from the USAF. I continued with that formally until 2013 when I decided that I'd had enough of the "state of the art" and shut down my business. That's the short story of it all... :) I still do limited amp work for a local store on vintage fender, marshall and ampeg amps....and some solid state stuff when they talk me into it.
     
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  2. robrob

    robrob Poster Extraordinaire Ad Free Member

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    I found that learning electronic theory by just reading was very difficult. I tried several times as a youngster because I've always been interested in electronics but the equation for parallel resistance blew my mind. When I actually started building electronics it motivated me to learn how they worked and that led me back to electronic basics and really learning the theory.

    An example I like to use for newbies is the typical 100k plate load resistor. I ask, "How much current is flowing through this V1A circuit?" Typically the answer is they'd have to disconnect something and put a multi-meter inline to measure current. When I explain that all of the tube's current is flowing through the 100k plate load resistor and since we know the value of the resistor we can measure the voltage drop across that resistor and apply Ohm's law to calculate the current the light bulb goes on. A simple, real world example of Ohm's law like that can motivate a budding builder to actually learn what's in the book.

    Also, when I realized I could use a calculator's 1/x key for that parallel resistor equation a huge light bulb came on for me :) I've always been a calculator freak so I was elated that I found a real world use for one of a scientific calculator's keys.
     
  3. Goldenshellback

    Goldenshellback Tele-Meister

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    First rule in soldering. Buy a high quality soldering iron and high quality silver solder.
    Second rule. Don’t grab things that you don’t know what they are or what they do.
     
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  4. Asmith

    Asmith Friend of Leo's

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    I learnt the equations at school, ohms law, P=IV and parallel resistance. Once your comfortable with the rules, its not hard to take the steps afterwards. I learnt everything I know online from places like @robrob's site, valve wizard, ampbooks and elsewhere through google.

    Anyone whos hand with a soldering iron can build an amp following a paint by numbers procedure from a kit. But if your ultimate goal is to be able to build something you cant get in a kit, you do need a genuine interest in the circuit design.
     
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  5. dougstrum

    dougstrum Tele-Afflicted

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    When I was a kid I got to watch my dad put together a Scott kit. In my mid 20's I worked with an old engineer who was into ham radio. I had an old Premier amp that I picked up at a junk shop. I kept the amp in my work space. I think Doc Ed was tickeled to see a young guy interested in tubes. That man taught me a lot during lunch breaks and slow Fri afternoons:)

    Tube amp book 4th edition~Pitman
    How to service your own tube amp~Mitchell; are two books that I have. If you can can follow a diagram you can figure it out~but sure is nice to have a mentor!
     
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  6. Jesco

    Jesco TDPRI Member

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    I'm surprised no one has mentioned Rob Robinette's website. I learned most of what I know from reading almost every page. It is an excellent resource for a beginner. Start from the breakdown of a champ circuit.

    I also used the AP Physics course on Khan Academy (free online modules) to learn the basics of circuits and Ohm's law.

    And of course, Uncle Doug's videos on the basics (if you watch it at 1.25 speed, it's even better).

    Still so much to learn...
     
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  7. dickey

    dickey Tele-Afflicted

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    Never did.
     
  8. bftfender

    bftfender Friend of Leo's

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    decide which way(variation) of the bassman you want to travel,,,then add speaker of need for your mix..sit it right on a P bass...guitar vol on 3-5 for cleanish..5-7 crunch..dime for leads...add MV (2204)toss an extra tube (900 slx) or pre type thing to angry( it up in it after a 3rd generation over the pond situation..maybe even whip out the TS
     
  9. Andy B

    Andy B Friend of Leo's Silver Supporter

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    Learned initially from my Father. My work as a camera repair technician refined my soldering technique. Got an AA degree at some point along the way. While repairing cameras and related equipment I started working in a commercial amp repair shop and opened a shop in a local music store when the other shop closed. Did that for three years until I retired. I still do selected work for my previous employer as well as freelance work as time permits.
     
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  10. black_doug

    black_doug Friend of Leo's

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    I was born curious about how stuff works.

    My brother and I both went to same college to study electronics and share an interest in it. He's got a workbench now in his basement and probably knows more than I do just from repairing and building stuff.
     
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  11. Platefire

    Platefire Friend of Leo's

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    I had a guy known on the internet as "Casey4s" talk me into doing a F51 Champ Kit. He even offered to hand make the kit plus the instructions. How could I refuse. He did just what he said and we created an amp that I'm still play on today. That was in 2001. A few years later he built a kit for the same amp, for my Son, that he also still has and uses. When I first started I read everything I could get my hands on about tube amps. I finally got to where I could build amps from scratch by myself---well almost by myself!!! I've always leaned heavily on the Hoffman Amp forum for advice and direction. Great bunch of folks there! Like it's been said, there are tons of info on the internet. All you got to do is search and read. Platefire

    BTW---My Lunch Box 5E3 variation called the T-Deluxe
    Scott T-Deluxe 027.JPG
     
  12. trev333

    trev333 Telefied Ad Free Member

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    My Dad was a tube amp geek through the 50/60's. He was the local MC/DJ and built his own PA amps and tube tape decks and serviced/repaired friends tv's and stuff.... I sat on a stool from a young age and watched him work/troubleshoot circuits...

    He used to explain what he was doing and what parts did what and basic safety.... most of it went over my head.... though a lot of the basics stuck....

    I was soldering stuff through primary school days....

    he stopped doing repairs when appliances came with printed circuits and used transistors... he couldn't use his old tricks on them.... gave all his tube stuff away to a younger guy at his work who showed interest in tube gear... and went fishing...:)
     
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  13. moosie

    moosie Doctor of Teleocity Ad Free Member

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    I learned everything that I know (limited) in the last few years, by reading some books and websites, building a few amps, and by modding and servicing a few old SF amps. It took me a while just to get my head around how tubes actually work in a circuit. It's pretty amazing, actually.

    Watch some Uncle Doug. Check out Rob Robinette's site. It's jam-packed with useful information, fairly accessible to the beginner, too. From those sources, learn to work safely. Then buy an old amp and tinker with it. It's a start.
     
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  14. jvin248

    jvin248 Poster Extraordinaire

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    .

    High school electronics classes.
    College engineering courses.

    .
     
  15. Uncle Daddy

    Uncle Daddy Tele-Afflicted

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  16. Jon Snell

    Jon Snell Tele-Meister

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    I learned the basics from my Dad in the 50s. Refused to take any exams at school then went with the Admiralty Under Water Weapons Establishment and enrolled as a Craft Apprentice Electrician for 5 years, then went to college and on to University.
    Never looked back apart from how to fix, design or build stuff no one else can manage and owned an ran a large repair workshop for 25 years. Retired now but still busy.
    I think it helps to be dyslexic.
     
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  17. Squawker

    Squawker Tele-Meister

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    Dad had a box with a few switches and bulbs and wirewound potentiometers. And we had a Hornby Dublo (three rail) model railway. And Subbuteo floodlights needed battery power. And I was curious. Then somebody at school had the bright idea of starting an electronics club, so at the age of 13 or so I signed up for that. Mostly we'd strip broken solid state circuit boards for usable components, then build things like flip-flops and headphone amps. At some point I must have started reading the theory, not just building circuits by rote - but I don't honestly remember where the information came from in the pre-internet days. Most likely the public library.

    So I stumbled through school, doing pretty well in physics and chemistry and the next step after VIth form was assumed to be university. By this time I'd been dabbling in computers - dad's office CBM 4016 and my own Vic-20, and some of the others had Sinclair ZX81/Spectrums, or even a BBC Micro!! Despite loving the programming side of things, I wasn't read to commit to computer sciences, so I signed up for a BEng in Electrical and Electronic Engineering. Still ended up on a computing track more than anything else, but in theory I know lots about waves and digital circuits, and everything from semi-conductor theory to 3-phase power generation. Not a lot on electron valves, I must admit.

    Roll on my 30th birthday and I decided to buy a guitar and try to learn how to play it. Cue one '96 MIM Standard Telecaster and a rapidly increasing interest in guitar amplifiers. I stumbled over the AX84 website. I bought Aspen Pittman's "The Tube Amp Book". I contacted Northcoast Music in the States to get decent copies of the Vox schematics. I bought Morgan Jones' valve amp books. I scoured the internet for reasonably priced parts - then I built an AC4. It wasn't a great build, but I learnt a lot, and was ready to apply new skills and new knowledge to other projects.

    I'm still not a great guitarist - anything but! I love the technology side of guitars and amplification. I rebuilt the AC4, I have a Doug Hammond Firefly with a Matchless Spitfire input stage. I build a GA-8 Gibsonette. And I'm always doodling away on some project or other waiting for the time and spare cash to do something about it.
     
  18. screefer

    screefer Tele-Meister

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    I'm in the same boat....green as grass. What is working for me is reading the SBro forum back from page 452 ( I'm on p. 310).
    An equal dose of Rob's site and Uncle Doug is also turning lights on.
    Persevere!
     
  19. Viejo

    Viejo Tele-Afflicted Silver Supporter

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    Technically I don't know electronics, I don't know the math. I can use the ohms law equations but that's about it. I know "practical" electronics. Go through and service the amp, clean and retension sockets, clean jacks and pots first, that may solve your problem. Then the Jack Darr handbook is a big help. Doug Hoffmans diagram showing signal flow through a Marshall was a big help. Reading books, watching videos. There are some very knowledgeable people on this forum who are very generous with their time and have helped me greatly. I am far from being a tech and often think the problem is caused by something other than what is causing the problem but I can usually find the fault and fix it
     
  20. Controller

    Controller Friend of Leo's Silver Supporter

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    I learned everything I know about electronics (almost nothing) from TDPRI. For some reason I enjoy reading these amp threads even though I understand about one percent of it.
     
    Last edited: Feb 10, 2020
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