Tube Amp Archive

Mine buzzes like mad, but when you crank it up the signal to noise ratio is fine. And I like to think that that's how it likes to be run

I'm reverse engineering my tube radio to a point where I can turn it into a guitar amp and then continue forward again. Pretty simple so far, considering all the nay-sayers on the internet of AA5 conversions.

This amp is based off a printed circuit board so that schematic is of no use to me. Do you have any idea why the 12BA6 doesnt want to work as a regular pentode? Is it just not designed to amplify audio frequencies? Or is it just a bad tube?

Well you guys have not been tons of help but I figure I'll ask. So I got the parts and pieces I needed in the mail today and started wiring it up. Well it turns out that how I have my circuit setup it didn't work. So I placed my input lead on the up side of the volume pot (as most people do) and sur...

Alright folks, I've re-done the schematic to include my modifications to most importantly, make the thing safe, and secondly, to make it an amp rather than a radio. [IMG:1023:699]http://i966.photobucket.com/albums/ae142/leviman2001/schematic-1.jpg[/img] Alright, so as you can see I've tapped into th...

Alright! So does everything I have sound good? Like it'll work? Haha

Well that's the plan... And I think I've determined that the isolation transformer I linked to in the original description will work. The rating on the bottom of the radio is 120 volts and 30 watts so that works out to .25 ampres which is within the specs on the transformer. Cool!

FUCHSAUDIO wrote:This is dangerous for sure. Play the guitar, touch a radiator, die. Not fun.

If I add an isolation transformer and a grounded cord would it not be safe then? Because that's the plan...

Read again please. My plan is to make it safe to operate. If you have any suggestions to help with that I'd love to hear 'em. But I'd like to kindly suggest anyone who's going to tell me to wimp out on this project to go away. Also as for the speaker, the schematic reads "voice coil 2.65 ohms" which...

Hey folks, I've been lurking around here and posted about my Gibson GA-15RVT I modded and now my text project is going to be the ever hated AA5 guitar amp conversion! :twisted: I hear lots of people saying "don't do it, you need to add and isolation transformer!!" Yeah... so what? That is very easy ...

Check out my thread on my GA-15RVT for the mods I did. I love the way mine sounds. Lots of mids and warm too (odd for a gibson).

Make sure your multimeter is a good one and isn't broke. I was reading 500+V on the plate of the EL84s of my amp, did a bunch of diagnosis and ruled out everything but the power supply (that was a sad day in which I thought my amp was fried). Then I tested a dead-ish 9v. On the normal range (20v) it...

Thanks guys! Here's the promised gut shot video. Sorry for the quality, it's just my cell phone, I don't have a video camera

http://www.youtube.com/watch?v=94zN6-4BWYk

It's okay, I bought a box of unkown tubes for $20 once. Turned out I didn't recognize any of them and can't find a use haha. But someday I will gain the skills to design a circuit from a datasheet and build crap out of all of em!

I just wanted to say, I'm damn lucky. I've been shocked by the B+ a few times. Once on my Pignose G40V. I installed metal case 6L6's but pignose didn't think of those tubes when they built the amp. So they used the pin that's used to ground the cases as a junction point for their anode resistors!! :...