The Amp Garage

I had the pleasure of repairing/restoring this old trooper on the weekend and playing it for a few days. Just thought I'd share. It had a solid state rectifier in it, but previous to that the socket was wired for a 6X4 :shock: and adhesive labeled on the chassis as such. It was also labeled for a 6L...

I have a few nice power transformers around I'd like to make use of. A couple are oil filled. No signs of leakage or anything though, and they seem to test OK. What are your thoughts on using them in a build? I know the oil contains PCB and if it leaks it's bad news. What about relative safety when ...

Thanks guys. Yeah there's not much to it... I can draw out a schematic... but before I mod it I just wanted to see how close it is now to original... doesn't look like much has been done. Usually I would just gut it and start fresh but I don't think I'll want to in this case. No doubt theres cap swa...

Anyone know a good source for Bogen schematics? I found what I think is a Challenger CHA-30. It's been painted unfortunately, but otherwise it looks original aside from whatever was added to the cover... can't find a Bogen schematic for this model though. Anyone know where to find one? More pics her...

perfboard just for testing? On the subject of the board, I scored some nice vintage bakelite sheets at another estate sale... I'm thinking of maybe drilling a couple them out for turrets to use as boards in these amps. I know this stuff is brittle though, anyone got any insight on doing that? (besi...

I scraped the numbers off the glass and put it back in... I'm going to cut some slots in the wood on top for cooling but it actually doesn't seem too bad, the back is open and the speaker cloth lets air through. https://i.imgur.com/cxSCxyF.jpg re: PTP... Why are people so against it? It was going to...

This is what I started with. I neglected to take a picture of mine before I started, so I stole this picture off the interwebs (only one I could find!). https://imgur.com/sLLvEwn.jpg It's an Eastman-Kodak amplifier out of a 16mm film projector. It uses a single 12AY7 driving a 12SL7 and two 35L6's i...

The problem was I forgot to give the first grid of the 6SN7 a DC path to ground. Thanks to all who replied. I guess I'll add myself to the random acts of stupidty thread

I'm building an amp from scratch. I've based it on the 5E3, except instead of a 12AX7 in the PI I'm using a 6SN7/6SL7. Anyways, all that works fine, I can feed a signal into the 6SN7 grid and get sound output. Low volume but it's there. Then I add in a pre-amp tube. I can feed the first grid of a 12...

It's my first ever build, I just used what I had kicking around. I was concerned about the extra capacitance the copper holes on the back would add, not to mention maybe arcing, so I scraped off the copper from a lot of them near the danger spots. I'll probably re-do it at a later date with my own b...

Well it makes sound! I had three 6sc7's around here, 2 of which were good, one was bad... but I can't find the second good one. So I powered it up with the weak one and it works, just can't get much gain out of it till I find a new tube. 360v plate to cathode voltage, which is higher than I'd like, ...

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I have a bunch of Italian Geloso PA amps that I paid <100EUR a piece Yup, these are a similar thing. The tubes these came with would have cost me more to buy. The red one was $25 CAD ...the black one was $40 and came with other stuff. Out of them I got 4 good 6V6's, 6SC7's, 6SF5's, 5z3 and a few ot...

...and the black one cleaned up pretty damn nice too...

I have also used Radio Shack solder and it was good too. Mike You must mean the earlier stuff from RS? ...or maybe the batch I got was bad. I got a bunch of rolls from a closing store in Myrtle Beach for dirt cheap, It always cures very dull and dirty looking. I threw it in the junk drawer and use ...