Building a tube amp

[Cooperman]

I've been researching over the last few days the practicality of building my own tube amp. I have a general electronics background and was wondering if anyone else has attempted anything like this. I've found some schematics on the net for preamps, power amps, power supplies and the like... does any one know of any good resources on the net that I might not yet have discovered or any good books on the issue. Of for that matter any schematics they can send me.

[Recording Engineer]

You're gonna have a field day with this one... See you next millennium...
http://astrosun.tn.cornell.edu/staff/loredo/ee.html

[Cooperman]

Thanks for the site Rec. Eng. I think that'll come in pretty handy. I don't think it's *that* much of a task. The main problem for me will be finding the time. In the Chem Department at my university we have an electronics workshop and one of the guys is into valves etc... and there's another tech staff guy who loves building practically anything... this guy is currently building me a Tesla coil for my experiments... and when I told him he had to build me one his face lit up!! So I don't think getting help rom these guys should be a problem.

Getting something to sound good is something else, but building something that works I don't think is that big a task.

As far as I know there isn't a fully illustrated, step-by-step procedure of how to build something like this on the net - you know with complete instructions, pics, diagrams etc... I think it'd be a cool task to undertake to not only build one, but to document its creation.

[Recording Engineer]

Yeah I have quite an electronics project too, but I have the schematics for it though; luckily.

Good luck on your project.

[CharlesThomas]

A few great resources. First of all, do a deja-new search for alt.guitar.amps. It's a great usenet group with some of the most knowledgable tube gurus out there. They helped me every step of the way when I started learning to modify and work on tube amps.

Next, there's the "AX-84 project", which is a step-by-step build-it-yourself tube amp project. http://www.ax84.com/

They'll love to help you out, 'cause they've all been there.

There's "Tube Amps for Beginners" http://members.aol.com/medmac/tubes/begin.html

Also, there's "Ampage", and some great people are also on there. http://www.firebottle.com/ampage/

For parts theres: http://www.mojotone.com/ http://wwww.hoffmanamps.com
and http://www.mouser.com

Best of luck. It's a blast!

Charles Thomas

[Daddy-O]

So far every one is pionting you in the right direction. But you need to get the "Bible" of tube amps....."The Tube Amp Book". And yes that is the name of it, This book covers everything from the history of the tempermental little things to specs and charachteristics of diferent makes. And in the back of the book you will find shematics to best tube amps ever made. The book also covers modifications, set up, how to bias the power tubes (very important!!!!) and troubleshooting. Two company that recomend for parts and a wealth of knowledge is Kendrick Amplifiers and Mojo Tone.......have fun!

[Cooperman]

Thanks for that Daddy-O... I was gonna go order a few recording books soon so I'll make sure to try and get that tube book too!

[hockey punk]

The tube amp book and tube amp book II were written by R Aspen Pittman and are available through Groove Tubes , 13994 Simshaw Ave. Sylmar California 91342 . I haven't looked for them on the web . These books are fabulous .

[Cooperman]

Thanks for the info hockey punk, I just did a search at amazon with no luck... if anyone has these books and could post the publisher and year of publication it'd certainly help when trying to order it in at a bookstore... otherwise I'll have to go thru Groove Tubes.

Are those two books radically different? Or is the second one just an updated version?

[Cooperman]

Actually don't worry about it... I just emailed the Australian Grrove Tubes Distributor to find out where I can get it.

Anyone have any suggestions for what tubes I should use? I was just gonna go for the standard 12AX7's and EL34's.

I'm thinking about using a rectifier tube or two in the power supply rather than solid state... pros/cons????

[Cooperman]

...although having just checked out that Mesa Boogie's, Crate Voodoo's and Peavey 5150's use 6L6's in their power amp stages I might have to go with these...

[CharlesThomas]

Hey Cooperman,

For a beginner just starting, I'd recommend something small, like a Fender Champ. It's a single power tube, single preamp tube, single rectifier tube class-A amp that's about 5 watts. But for home recording, they're absolutely incredible. The tone is so pure on them, and they have only a handful of parts.

Jumping in head-first with a four-power-tube, tube-rectified, phase-inverted, two-channel, 10 gain stage preamp project may quickly overwhelm you.

Another great suggestion is to do what I did... get a SF bassman or Bassman 100 and modify it to be whatever amp you want. You can turn them into a BF Bassman, almost any model of Marshall, any of the Tweed Fenders, etc. They don't have reverb or vibrato to make things complicated, and they have a LOT of room to work in there. They're also hand-wired which makes it a lot easier to understand what's going on than if you're working on a PC-board amp.

Good luck!

CT

[hockey punk]

The tube amp books are in my hands right now and do not list a publisher , so I suspect they were printed by someone for Pittman .They are mostly schematics of every version and up grade of every fender imaginable .If I can add a personal preference for power tubes for guitar I like 6L6's for their natural compression that produces that wonderful sustain .

[Cooperman]

Charles Thomas:

I'm not really after that vintage Fender kinda sound... more a modern hi-gain sound. I've rigged up a photomultiplier tube (similar to a valve) with a 2000V power suppy and managed to not get lost and not electrocute myself so if I have circuit diagrams to follow I don't think it'll be a huge problem. Not only would I like to use it to record with but also to play out with. How cool would it be to have someone come up to you and say "Great tone - what amp are using? and to tell them it's something you threw together from some bits and pieces...hehehe!! But thanks anyway!

hockey punk:

As I said I'm waiting on a response from the Groove Tubes distributor here - hopefully I should be able to pick the book up through them.

Most amps I've seen use 12AX7's in the pre... I am assuimg then this means that really it's the power section that defines the characteristics and tonality of an amp?

[S8-N]

COOP: Just get a POD and retain a bit of your sanity...
I have a bass tube preamp that was built by a local guy who builds tube amps...
His amps look like a 20 watt practice amp, yet fry your eardrums at half volume...
He's kinda scary... A total christian... Doesnt hear very well... Spouts biblical nonsense at random intervals... But come to him with a sonic problem... Like how to make a 6 string guitar play like a 7 string without bowing the neck and frying the intonation... He makes it work.
The damned preamp has never worked... Shorts out when you slap the E string... Clips.... Sounds pretty cool as long as you dont slap the E string... Apparently he cant fix it...
It looks cool, though...

[Cooperman]

S8-N... maybe I'm seeing things in a fairly simplistic manner, but if I've got a diagram to follow I don't see where the problem will be. It's not as if I'll be designing it from scratch. Plus as you said it'll look cool... I'm a big fan of stuff looking cool... my fav guitars Jacksons and BC Rich's - I think that says enough!!

[CharlesThomas]

> am assuimg then this means that really it's the power section that defines the characteristics and tonality of an amp?

Nah, it's a pretty equal partnership. The preamp is where your sound and tonality is shaped, and where your gain is generated. The power amp section adds its own flavor to things, depending on how much your amp is turned up. 12AX7 are the most common preamp tube because they have the most gain, but AT and AU7's are also common in the lower gain older Fenders. Then each poweramp tube has a distinctive "spin" that it puts on the sound. EL34's are the "classic" Marshall sound, while EL84's are the more British "Vox" sound. 6V6 and 6L6 are other very common power amp tubes. But it's not as much the tubes as how they're all configured that makes the sound. For example, a 5150 and a Blackface Bassman each use 12AX7 and 6L6 tubes, but they don't sound anything alike.

> I'm not really after that vintage Fender kinda sound... more a modern hi-gain sound.

I wasn't suggesting the Champ for its tone, but more because it's easier to learn on.

The problem with your project is that high gain amps are even more critical when it comes to circuit design, component layout, (and ESPECIALLY) lead dress. Any tiny flaw in one of these areas will produce oscillations that will sap your tone and cause uncontrollable, howling feedback from inside the amp.

Building a tube amp is no easy task, and a lot of it falls more into the "art" category" rather than the "science" category. That's why everyone doesn't do it themselves.

But I expect you'll find out for yourself soon enough!


> How cool would it be to have someone come up to you and say "Great tone - what amp are using?" and to tell them it's something you threw together from some bits and pieces

www.hoffmanamps.com has a section that outlines every part you'll need to build an amp. Sort of a checklist of everything you'll need from transformers, chokes, and tube sockets to resistors, pots and knobs. It's a good thing to check out.

>maybe I'm seeing things in a fairly simplistic manner, but if I've got a diagram to follow I don't see where the problem will be.

Heh. Famous last words.

My advice to you is still to start with a Bassman or Bassman 100 and modify it from there. I built a four-gain stage, two channel Marshall clone into one of mine, and the changes to make a Mesa Boogie, or Randall, or whatever you're after would be a lot less work than building from scratch.

But any way you take on the project, you'll learn a lot and have a lot of fun. I find soldering really theraputic.


[This message has been edited by CharlesThomas (edited 05-31-2000).]

[This message has been edited by CharlesThomas (edited 05-31-2000).]

[robnoxious]

The original Boogie MKI's were just Fenders that Randall Smith rebuilt in his shed.
Good Luck

[gaffa]

Coop,

go get 'em . I've been tossing up building a tube amp for a while. I've built some solid state amps before (it's all I actually have for amping guitar, and they aren't brilliant, but they work most ofthe time), but if you want to have some one a bit more "local" - and I use that in the loosest sense of the word cos it's still 6000km - to chat with, I'm up for it. Also, if you need to import stuff, and you kind of have to buy in bulk, wel you could count me in in an atempt to lowerth e import price or what ever.

And lastly, I don't know what the state of play is in Perth re electrnoics places, but there are some reasonable ones here whioch I visit reasonably regularly, so just give me a whistle if you need anything.

- gaffa

[Cooperman]

Thanks gaff, I've gotten some prices on some Groove Tubes from this dealer in Brisbane... I think it was generally $30 for pre amp valves and about $50 for power amp valves. I didn't think this was that unreasonable... I think the big cost is gonna be for the transformers and the choke. I can't say for sure, but I'm guessing these are made especially for amplifiers... and consequently are gonna be expensive... plus the shipping on them is gonna be pretty bad cos of the weight.

I'm still waiting to hear from my local music store about the Groove Tubes book... I'm gonna contact them tomorrow... if they can't get it in then that place in Brisbane can get it for me. Once I've got that and have gotten some plans of what I need to get and do... I'll hopefully make a start... as long I don't get snowed under with work at uni.

Thanks for the offer of help... if I can't get what I want here in Perth I'll make sure to give you buzz to see if you can help me out.

[Cooperman]

Don't ya hate it when stuff get's posted twice

[This message has been edited by Cooperman (edited 06-06-2000).]