Amp building

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neato
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Amp building

Post by neato » Thu Sep 29, 2022 12:12 pm

Hello,

I've been meaning for a long time to learn how to build my own amps. Ive dabbled in some pedal builds and had a lot of fun and figured why not.

However, I'm not sure if there are any suggested starting places?

I've purchased a book "Guitar Amplifier Electronics: Basic Theory by Richard Kuehnel" as a high level overview and that has been fun digging through. But I'm not sure if there is a dedicated online forum around, or recommended places to buy kits? I know of Mojotone but wasn't sure about any other resources.

Thanks all

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Re: Amp building

Post by Dr Tony Balls » Thu Sep 29, 2022 12:32 pm

I started with a Weber kit ages ago. They're somewhat known for not being the best around. They provide you with shit, unmatched tubes, sometimes the jacks and pots were shit, and they dont come with instructions, just a schematic, a layout, and at the time they had a messageboard. The iron, chassis, cab, and speaker (if building a combo) are all great though, and that's what counts. Given the relative drawbacks, though, I thin I learned a bit more about how things are done and why they are done, whats shit, whats good, all that. That was a dozen years and ~60 amps ago.

I will say this, within reason build what you want to build. If you want a JTM45, build a JTM45. Dont think you have to go with a tweed champ to start just b/c it'll be simpler.
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Re: Amp building

Post by neato » Thu Sep 29, 2022 12:36 pm

Dr Tony Balls wrote:
Thu Sep 29, 2022 12:32 pm
I started with a Weber kit ages ago. They're somewhat known for not being the best around. They provide you with shit, unmatched tubes, sometimes the jacks and pots were shit, and they dont come with instructions, just a schematic, a layout, and at the time they had a messageboard. The iron, chassis, cab, and speaker (if building a combo) are all great though, and that's what counts. Given the relative drawbacks, though, I thin I learned a bit more about how things are done and why they are done, whats shit, whats good, all that. That was a dozen years and ~60 amps ago.

I will say this, within reason build what you want to build. If you want a JTM45, build a JTM45. Dont think you have to go with a tweed champ to start just b/c it'll be simpler.
Appreciate the advice, thanks! Yeah i've seen people recommend the simplist kit possible at first and while I understand where they are coming from, if the person building the kit isn't excited for it because it's not the amp they want, I imagine that would lead to many unfinished amp projects.

I'm hoping to find one that has good documentation as I would really like to learn "why" all the parts work together and why it was designed the way it was. I'm a designer by trade so I like all that stuff :D

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Re: Amp building

Post by JackFawkes » Thu Sep 29, 2022 2:14 pm

I've never built an amp, but the little bit that I know about amp circuitry, I learned from reading Rob Robinette's Tube Amplifier Website.
Not only does it have a lot of excellent information about how amps work and how to read and understand diagrams, but he has a whole bunch of information on micro amp projects you can build as well.

Jack

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Re: Amp building

Post by wproffitt » Thu Sep 29, 2022 2:41 pm

I agree with all that had been said in the replies above. I built a 5e9 tweed Tremolux (imagine a tweed Deluxe) with an onboard tremolo) back in 2017 and lobed not only the build process, but the finished product as well. Did It work on the first try? No! Did I eventually get it running with some advice from fellow forumites? Yes! I’m performing with it tomorrow and still love the way it sounds. Check out Dave Hunter’s book on tube amps [url="https://www.amazon.com/Guitar-Am ... p Handbook[/url]for a bit background reading on some of the classics. Also, this [url="https://www.valvewizard.co.uk/se ... lve Wizard[/url] website is full of great information.

If you want to go with a kit with great documentation and support, I hear great things about Trinity amps.

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sal paradise
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Re: Amp building

Post by sal paradise » Fri Oct 07, 2022 9:52 am

JackFawkes wrote:
Thu Sep 29, 2022 2:14 pm
I've never built an amp, but the little bit that I know about amp circuitry, I learned from reading Rob Robinette's Tube Amplifier Website.
Not only does it have a lot of excellent information about how amps work and how to read and understand diagrams, but he has a whole bunch of information on micro amp projects you can build as well.

Jack
This site is awesome. and now I want to build a Princeton micro. I might do this. It’s about time I learnt how to do electronics, and how to solder properly.
I have nothing to offer anybody, except my own confusion?

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Re: Amp building

Post by jthomas » Fri Oct 07, 2022 10:26 am

Weber kits are fine and at a good price point.

Tube Depot (in Memphis) has some kits and they have some videos on their website showing the construction.

Robinette's site is a tremendous resource and Dave Hunter's book is a good place to start.

https://www.amazon.com/Guitar-Amplifier ... 087930863X

You also might look up "Uncle Doug" on YouTube. He does amp repair, but also has build at least 1 (maybe 2) amp(s) from scratch and demonstrates his process. He also has some instructional videos talking about caps and resistors, power filtering, etc.

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Re: Amp building

Post by øøøøøøø » Sun Oct 09, 2022 1:02 pm

Building tube amps can be as shallow or deep as you want, really.

Much of what you'll find on the topic is based on what my dad used to call "horse sense": a sort of developed intuition and instinct that will lead you to a workable conclusion most of the time, despite not understanding much about the theory (a good example of this is the old Ted Weber books).

The thing is, this is totally valid and can work perfectly fine; old Fender, Marshall and Vox circuits are simple enough that some basic rules of thumb (and awareness of certain potential pitfalls) are all that's really necessary to put together a working amp that sounds pretty good (as long as you aren't trying to reinvent the wheel too much).

But there's also this whole other level where you start to operate with greater understanding of the factors you're actually manipulating, and can proceed with intent toward a sound you like (instead of relying on a mixture of luck, superstition, and specious hearsay).

Most of us start out working from that first place, and it can be plenty gratifying. But there's also something to be said for pushing toward that other level, and the best author I've found who does that is Merlin Blencowe, aka "The Valve Wizard." He has three books in publication and I can recommend all three.

They're a pretty good balance of theory and praxis, in my view--he illustrates the mathematics, but you can kind of skim over the mathiest bits if your mind doesn't work that way. His texts are definitely written with an appropriate awareness that advanced calculus doesn't have to be a prerequisite for building a good amp (but it can sure help with being an effective designer).

For a starting place, it doesn't get much easier than a good 5F1 Champ kit with a good set of instructions. There are numerous options out there. Can you take a bigger bite and start with a 5F6-A Bassman or something more complex? Sure, and you might succeed.

But the low stakes of the simple/small/cheap Champ is what makes it a good idea, in my view.

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Re: Amp building

Post by jthomas » Sun Oct 09, 2022 6:48 pm

I am in the process of re-building a Weber Maggie kit that I initially put together in 2012.

I've played around with different components modifying my original build and it is just plain ugly... thus my rebuild. This is a Dave Hunter Two-stroke with one output tube, so otherwise a One-Stroke. It is a Champ that has a beefy power transformer and output transformer that allows for using KT66's, 7581's, 6L6's and 6v6's, has a tone control, and a switch to change the voicing of the preamp tube.

I thought that I would provide a few notes about the cost of a scratch-build.

The Weber kit with everything (cab, chassis, tubes, speaker, and every thing else) currently is $730.00
The Weber kit without cab, speakers, hook-up wire, tubes, and chassis is $495.00
Everything needed to build the amp (not including chassis, tubes, wire, power cord) costs = $208 purchased through Weber (transformers) and amplified parts.

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Re: Amp building

Post by hulakatt » Mon Oct 10, 2022 3:49 pm

neato wrote:
Thu Sep 29, 2022 12:36 pm
I'm hoping to find one that has good documentation as I would really like to learn "why" all the parts work together and why it was designed the way it was. I'm a designer by trade so I like all that stuff :D
Marsh amps has really good documentation for a first time build but it's more of How than Why. Good kits too.
Valvestorm makes great ala carte Marshall kits with good documentation.
Mojotone kits are solid with just a layout and schematic.
Triode Electronics are good kits with just a layout and schematic.

I hear good things about Trinity but they're mostly original or heavily tweaked circuits.

Weber are OK, decent for the price.
Boothill kinda suck.

I've built several tweed Champs and...
Tweed Champs are great because it's a pretty simple circuit that's great to cut your teeth on!
Tweed Champs suck because that's a lot of intricate solder work crammed into a very tight and small chassis!

Marshall type chassis and Fender BF chassis are great to work in with lots of elbow room but they are more complex circuits.

TLDR: If you want a Marshall, look at Valvestorm. If you want an old Fender, look at Marsh. If you can work from a schematic or layout, you got options.
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Re: Amp building

Post by ryland » Thu Oct 13, 2022 7:10 am

hulakatt wrote:
Mon Oct 10, 2022 3:49 pm

I hear good things about Trinity but they're mostly original or heavily tweaked circuits.
I built a Trinity Triwatt and it sounds fantastic and had amazing documentation. I think they're going to re-launch their amp line soon.

I've also recently built a few Mojotone amps, but those had no documentation and I made quite a few reliability tweaks to them:
5e7 Bandmaster,
6G2 Brown Princeton,
Working on a 5E8a piggyback combo currently...just need the very specific power transformer to come into stock.

The Psionic Audio Youtube channel is fantastic, I've picked up a ton of tips and understanding from it. The video on the Marshall grounding scheme and grounding in general is amazing and worth a search.

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Re: Amp building

Post by øøøøøøø » Thu Oct 13, 2022 7:51 am

A generally applicable caveat:

The internet is the world’s largest repository of misinformation, and tube amps are no exception to this.

In earlier years (when I *thought* I knew a lot more than I actually did) I probably even contributed some.

Most of the time the sorts of bad tube amp info you run across won’t kill you. But sometimes it very well might.

Building a kit is pretty safe if you follow all instructions. For anything beyond that, vet your sources very carefully, keeping in mind that the loudest, most confident, and most-prominent voices are often dead wrong.

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Re: Amp building

Post by N0_Camping4U » Thu Oct 13, 2022 11:43 am

ryland wrote:
Thu Oct 13, 2022 7:10 am
hulakatt wrote:
Mon Oct 10, 2022 3:49 pm

I hear good things about Trinity but they're mostly original or heavily tweaked circuits.
I built a Trinity Triwatt and it sounds fantastic and had amazing documentation. I think they're going to re-launch their amp line soon.

I've also recently built a few Mojotone amps, but those had no documentation and I made quite a few reliability tweaks to them:
5e7 Bandmaster,
6G2 Brown Princeton,
Working on a 5E8a piggyback combo currently...just need the very specific power transformer to come into stock.

The Psionic Audio Youtube channel is fantastic, I've picked up a ton of tips and understanding from it. The video on the Marshall grounding scheme and grounding in general is amazing and worth a search.

God I want to do a 6G2 Princeton head build. But I've only soldered once in my life. IDK if I have the skills to build an amp.
"I've been waiting for you, Obi-Wan. We meet again, at last. The circle is now complete. When I left you, I was but the learner, now I am the master."

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Re: Amp building

Post by ryland » Thu Oct 13, 2022 12:06 pm

N0_Camping4U wrote:
Thu Oct 13, 2022 11:43 am
ryland wrote:
Thu Oct 13, 2022 7:10 am
hulakatt wrote:
Mon Oct 10, 2022 3:49 pm

I hear good things about Trinity but they're mostly original or heavily tweaked circuits.
I built a Trinity Triwatt and it sounds fantastic and had amazing documentation. I think they're going to re-launch their amp line soon.

I've also recently built a few Mojotone amps, but those had no documentation and I made quite a few reliability tweaks to them:
5e7 Bandmaster,
6G2 Brown Princeton,
Working on a 5E8a piggyback combo currently...just need the very specific power transformer to come into stock.

The Psionic Audio Youtube channel is fantastic, I've picked up a ton of tips and understanding from it. The video on the Marshall grounding scheme and grounding in general is amazing and worth a search.

God I want to do a 6G2 Princeton head build. But I've only soldered once in my life. IDK if I have the skills to build an amp.
The 6G2 is not something to attempt if you're new to this. I had to take an existing Mojotone chassis and create an adapter plate for a transformer with the correct voltages to start with. It also took a bit more planning than usual to get everything to fit correctly. It does sound great, though. I'd build it in a Princeton Reverb chassis if I were going to do it all over again.

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Re: Amp building

Post by Dr Tony Balls » Fri Oct 14, 2022 6:45 am

Things I just thought of...

1) A good tool to have for startup and a very easy one to build is a light-bulb limiter. Plan on that.

2) Tweed-style Fender amps have a relatively crowded and cramped chassis, compared to 60's Fender-style amps or most English style amps. A lof of people start on tweed style Fenders so i'm sure its okay but if you want more room to work, the other style kits provide you with that.
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