Need Help with a project for my Electronics Class

[RG_76]

Hi all!

I am currently an electrician\instrumentation apprentice at a copper mine in Arizona. Last week, our instructor asked all of the class to come up with an electical\electronics project for his class. The main catch with the project is that he gets to keep it after we are done with it so future classes can learn from it.

Being the ambitious little bastard that I am, I asked if i could make a home made distortion pedal and small tube amplifier.

The problem i am having is that I can't find parts to make an amp, or I can find schematics, but not parts lists. I just want to make a simple, inexpensive amp since he is keeping it for his class.

My questions for all that can help are:

Where can I find a parts list/schematic for a simple (haha) tube amp? If you know of any place that has a kit that would be cool too, but I am on a tight budget, and I have to give the things to the instructor when I am done.

If possible, what are some names of small tube amps that I could maybe find in a pawn shop or on evilbay that I could take apart and put back together on a different board?

All help is greatly appreciated! I will post pics of the project as it progresses

thanks in advance!

[rgr]

Distortion pedals are pretty easy, there are tons of schematics on the 'net. A small tube amp, say a Champ style amp, aren't hard, as long as you remember your working with lethal voltages, but the parts aren't cheap. I think Mojo, www.mojotone.com, has some kits, but I know a JTM45 head kit is around $1K. You might try the pawn shop route or check de 'bay for old amps in project or non-working condition.

Wouldn't a killer pedal be enough or do you need to make the amp too? If you build a killer pedal, you could build yourself one too

[RG_76]

thanks for the quick reply!

My instructor is expecting a masterpiece from me, and he expects me to build the distortion pedal and the amp. I wanted to build something that would blow away all of the other projects, and if I can pull this off, I will

I have looked at a few distorion pedal schematics, and the don't look too tough, and I can get all of the stuff for them at radio shack i believe. It's the amp i am worried about lol.

I think the "champ" style amp is what I am going after, I just need to figure out if it's possible to do it cheaply LOL :P

[Ant1981]

I built a distortion pedal once, I don't know where the diagram is though but some hobby electronics mags will have back issues you can try and search, suprised you didn'y find one online. But as rgr says, with a valve amp, you're working with some high voltages there - no room for error, just dont drop that screwdriver or slip with a probe!

[rgr]

ARRGGGHHHH, I had a long response typed up with links that got dropped because Jemsite logged me out, here goes again...

I used to build pedals for a store in NC, I even got one review on HC, http://www.harmony-central.com/Effec.../Fatbox-1.html. It was a really simple circuit, a single opamp design with no tone control, you can figure out what it was based on, it's "thing" was that it had a 5-way switch to select clipping diodes. Distortion/Fuzz/OD pedals are pretty easy, there are tons of resources on the net with a little googling.

The amp is going to be your problem mostly because of cost, what is your budget? Tube amps just aren't cheap to build because of the transformers, filter caps, chassis, and tubes. Your best bet will be to find a old amp to rebuild, but if you buy a broken amp, you don't know if the transformers are good or not, which is one of the biggest items you are trying to get out of it. There is a good supplier near you for this stuff, Antique Electronics Supply, www.tubesandmore.com.

Here's a link to a good selection of tube amp schematics: http://www.drtube.com/guitamp.htm

Generally people build tube amps for the experience, not to save money, it usually costs more than buying one, especially when you factor in the time required.

[RG_76]

my budget on the amp is $100 max. I might end up settling to make a pedal or 2 since I have had zero luck finding inexpensive amp parts lol. I had no clue that it costed so much to make an amp, even a small one at that.

Unless I can get my hands on some parts quick, i am going to scale my project back a bit and maybe make the amp at a later time.

Thanks for all of your help!

[rgr]

Yeah, it's hard to get the transformers for that amount. Even "fixer-upper" old tube combos go for that much or more. For pedal parts try www.smallbearelec.com, they have a good selection of enclosures and parts. You can get pots, jacks, resistors, caps, etc... alot cheaper through www.digikey.com or www.mouser.com but you'll have to do more work to pick out the parts.

[SalemB]

Try ax84.com for info about building tube amps. There's lots of info for builders and links to sites that sells parts.

[red5]

www.drtube.com has some schematics. I have a guys aim who used to build JTM45 replicas too, I can ask him if he'd be willing to help.