Anyone work on Amps too?

[fractal33]

I bought a Marshall 2203 reissue from reverb a little while ago and it arrived with a broken FX loop(which is kinda the whole point of the reissue for me.) So I took it to an amp tech a day or two after I got it and didn't get it back until nearly two weeks later. Once I finally had it back and spent some time playing it, I realized I was getting really bad hum/buzz using the high input. Anyway, I didn't want to go back to a tech, and here I am building and starting to design my own pedals so I thought this was a good opportunity to learn a little more about tube amps. After much blood, sweat, and tears, and a little help from some nice folks on another forum and some guidance from the tech who fixed the loop, I finally ended up tracking down the source of the hum which was a blown "hum balance" trimmer. Kind of ironic eh? I did run into one condescending guy on this other forum that told me I needed to go to college for 5 years before working on amp, so obviously I was even more driven to do this myself and stick it to him. It was a very interesting learning experience and I had to do quite a bit of research on safety precautions before I felt comfortable poking around in there. Being careless inside a 9v pedal ain't gonna kill you but a 100w tube amp on the other hand...

Just curious if anyone else on here dabbles in tube amp repair/building/modification. There is definitely a crossover with the pedal building, but I've come to learn high voltage work is a different animal. Once I started to understand the basics of how a tube actually works it became much clearer but I still have a lot to learn. I definitely felt like I was learning in reverse because in my head I'm comparing a transistor's functionality to a tube when obviously the tube came first. Heaters, plates, transformers, yada-yada, lots of stuff that you don't come across building pedals.

 

[PBWilson1970]

I'm gearing up to build some amps. A few friends and I decided to give it a shot and spent lots of time on the various forums. Luckily there's a lot of documentation going around these days and even voltage readings to help troubleshoot.

The amps that I'm assembling are a Trinity Tramp head (small Tweed single-ended amp with a good deal of flexibility), a Marshall 18 Watt clone and a Komet 60 Clone (called the Asteroid on some forums). The last one is most likely more than I need but it's such a great circuit and I got the transformers for a good price so why not?

I also have a local builder who said he'd take a look at them during first fire up to make sure everything is as it should be. Gives me confidence for sure.

 

[thesmokingman]

built them, modded them, repaired them ... I started in amps first then moved to pedals

 

[Dan0h]

This is the the direction I am headed. I am recapping my 70’s 100w tube amp this weekend. I too was shocked… surprised when I saw those filter caps holding 600volts well after the amp was powered down and unplugged. I drained them down before putting my hands in there. Pretty scary to think about your child accidentally being curious and touching one of those. The current caps are originals so over 40 yrs old. Going to move them to the inside of the amp so there’s no way they can be touched without pulling the chassis out. Also putting in a couple 220k resistors to help speed up the draw down on them. The original schematic has them but when they built this guy they didn’t install them. Excited, I’m also on the fence for doing a deluxe reverb clone. Be safe.

 

[thesmokingman]

This is the the direction I am headed. I am recapping my 70’s 100w tube amp this weekend. I too was shocked… surprised when I saw those filter caps holding 600volts well after the amp was powered down and unplugged. I drained them down before putting my hands in there. Pretty scary to think about your child accidentally being curious and touching one of those. The current caps are originals so over 40 yrs old. Going to move them to the inside of the amp so there’s no way they can be touched without pulling the chassis out. Also putting in a couple 220k resistors to help speed up the draw down on them. The original schematic has them but when they built this guy they didn’t install them. Excited, I’m also on the fence for doing a deluxe reverb clone. Be safe.
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fwiw I was never more frustrated by an amp build than when I did a Princeton Reverb and one of the RCA cables to the reverb pan was bad ... because your default is to assume it's a resistor/cap/tube/transformer or the reverb pan and not something stupid like an ostensibly brand new cable

 

[HamishR]

Like the Smoking Man I started on amps before getting into pedals. I can say that if you have a problem with a tube amp it is usually a tube. And problems with FX loops are often just the jacks not shorting properly.

I have had no electronics education at all, but have a brain, am curious and can work logically. I have read a lot about how amps work and how to build them and there are a lot of people online who can help. Unfortunately there is also a lot of wrong info and people who think they know more than everyone else, but just ignore them. Amp forums can bring out the patronising in people so I don't have much to do with them - a shame, because you can learn a lot too.

But building an amp which sounds better than anything you can buy in a shop, with less noise and fizz, and tighter lows, complex mids, etc etc is wonderful. It's also addictive, just like building pedals. If not more so!

 

[vigilante398]

I do both, but I have to limit my amp builds as it's easy for them to get wildly expensive. I've made good money buying broken tube amps to fix and flip, but building from scratch is a lot more satisfying.

 

[PapaBear]

I've dabbled in amps a bit, but very little bit

 

[fractal33]

Good to know so many of you also have experience with amps! I really want to build one now after all of this.

Turns out the condescending guy playing gatekeeper on the other amp forum was none other than the only living founding member of Marshall. Told me I was a prime example of someone who goes on youtube and thinks they know everything. All I did was state that I have some knowledge of circuits in the scope of building guitar pedals and I was willing to learn and try to fix this problem without a tech.

The whole thing really made me miss the PedalPCB forum. Fortunately, there were some less bitter people there that helped me out. Now I know I can bug you guys instead. Just kidding, well sort of.

 

[thesmokingman]

Good to know so many of you also have experience with amps! I really want to build one now after all of this.

Turns out the condescending guy playing gatekeeper on the other amp forum was none other than the only living founding member of Marshall. Told me I was a prime example of someone who goes on youtube and thinks they know everything. All I did was state that I have some knowledge of circuits in the scope of building guitar pedals and I was willing to learn and try to fix this problem without a tech.

The whole thing really made me miss the PedalPCB forum. Fortunately, there were some less bitter people there that helped me out. Now I know I can bug you guys instead. Just kidding, well sort of.

don't visit All in Good Fun then

 

[vigilante398]

There are a handful of DIY forums that have a welcoming community that are polite and civil. Unfortunately there are a great many more that are unwelcoming, condescending, and unhelpful.

This is one of the good ones.

 

[fractal33]

don't visit All in Good Fun then

It's one thing to vent about it there through comedy, another when someone is just asking for help and told to go to college for 5 years. And apparently, I'm the one that insulted him.

 

[vigilante398]

It's one thing to vent about it there through comedy, another when someone is just asking for help and told to go to college for 5 years. And apparently, I'm the one that insulted him.

If it's any consolation Bruce Egnater said that one of my tube preamp pedal designs was garbage, so that was neat. And I already had my EE degree at that point.

 

[vigilante398]

Also I should mention, anyone that tells you to go to college before working on amps probably hasn't gone to college. No universities that I'm aware of teach analog circuits at the level you need to have an understanding of tube amplifiers, especially at the undergrad level. Guess where that knowledge comes from these days? FORUMS.

 

[fractal33]

Also I should mention, anyone that tells you to go to college before working on amps probably hasn't gone to college. No universities that I'm aware of teach analog circuits at the level you need to have an understanding of tube amplifiers, especially at the undergrad level. Guess where that knowledge comes from these days? FORUMS.

Yeah exactly. I get that a lot of people in my generation think they can learn everything on the internet and that must get annoying to someone who has been working on amps for longer than twice my lifespan, but the thing is... well actually you can learn pretty much everything online if you have some common sense and a strong work ethic. I've taught myself more than I ever learned at college through means of the internet and am quite proud of the things I have accomplished when I set my mind to something. I don't think I have an innate talent for anything, but the one thing I do have going for me is endless curiosity and an extreme passion for the things I take interest in. I will stop at nothing to figure something out or learn a new skill. At the end of the day, that mindset is worth far more to me than any education alone.

 

[coltonius]

Yeah exactly. I get that a lot of people in my generation think they can learn everything on the internet and that must get annoying to someone who has been working on amps for longer than twice my lifespan, but the thing is... well actually you can learn pretty much everything online if you have some common sense and a strong work ethic. I've taught myself more than I ever learned at college through means of the internet and am quite proud of the things I have accomplished when I set my mind to something. I don't think I have an innate talent for anything, but the one thing I do have going for me is endless curiosity and an extreme passion for the things I take interest in. I will stop at nothing to figure something out or learn a new skill. At the end of the day, that mindset is worth far more to me than any education alone.

That's how I taught myself to build pedals- not just assembling, but what the different components and gain structures do. I've recently applied this to amp building, which isn't too far off conceptually!

My biggest problem now is that amp building is just as addicting as pedal building and 10x more expensive!

 

[fractal33]

That's how I taught myself to build pedals- not just assembling, but what the different components and gain structures do. I've recently applied this to amp building, which isn't too far off conceptually!

My biggest problem now is that amp building is just as addicting as pedal building and 10x more expensive!

Some people have the type of brain that immediately leads them to want to know the why and how and some are fine with just following instructions and like the gratification of assembly. I don't mean any condescension by that because they are both valid and who am I or anyone else for that matter to tell a person how to live their life or enjoy their hobbies.

It took me tubescreamer kit from stewmac and 1 PedalPCB build till I started teaching myself what was going on under the solder mask. Some people it might take 100 builds, some never do, but that is just how it went for me. I had to give myself some basic physics refreshers just to even comprehend what was going on from guitar to electricity to pedal to amp to a speaker vibrating air molecules. LTSpice was invaluable in the beginning to really get an understanding of what was happening on a basic level as far as understanding circuits.

I build so that I can have complete control over my guitar's sound so obviously tweaking and eventually designing my own circuits was in the cards for me. Having the same control over my amp is also appealing but considering how much I've spent on pedal building already, what you said definitely concerns me.

 

[coltonius]

Some people have the type of brain that immediately leads them to want to know the why and how and some are fine with just following instructions and like the gratification of assembly. I don't mean any condescension by that because they are both valid and who am I or anyone else for that matter to tell a person how to live their life or enjoy their hobbies.

It took me tubescreamer kit from stewmac and 1 PedalPCB build till I started teaching myself what was going on under the solder mask. Some people it might take 100 builds, some never do, but that is just how it went for me. I had to give myself some basic physics refreshers just to even comprehend what was going on from guitar to electricity to pedal to amp to a speaker vibrating air molecules. LTSpice was invaluable in the beginning to really get an understanding of what was happening on a basic level as far as understanding circuits.

I build so that I can have complete control over my guitar's sound so obviously tweaking and eventually designing my own circuits was in the cards for me. Having the same control over my amp is also appealing but considering how much I've spent on pedal building already, what you said definitely concerns me.

It will definitely help you realize what you like/don't like! I can't bring myself to sell any of my builds (yet), but I may have to.. My overflow has crept into my classroom at school!

 

[fractal33]

It will definitely help you realize what you like/don't like! I can't bring myself to sell any of my builds (yet), but I may have to.. My overflow has crept into my classroom at school!

Yeah I haven't sold anything yet either but now that I'm getting the graphics down I'm debating trying to at least help pay for my pedal building habit. I see a decent amount of PedalPCB builds on reverb being sold, but I don't want to accidentally get into some weird competition with other members here and drive the prices down even further.

 

[vigilante398]

Yeah I haven't sold anything yet either but now that I'm getting the graphics down I'm debating trying to at least help pay for my pedal building habit.

That's where it starts I started selling to offset the price of builds I wanted to do for myself, and now I sell way too many. PedalPCB boards are probably the best out there for people to get started in my opinion, but obviously if you're selling builds with them then you're going to be competing with everyone else that uses them, which makes it harder to stick out.

Not that big of a deal if your only goal is to break even for parts or make some beer money though.