The Amp Garage

[quote="kgreene"]I'm still a bit mystified about that amount of idle current. Will the 6v6's tolerate that?[/quote The numbers don't add up, something is wrong with your test setup....the voltage across the cathode resistor indicates 74 mA total for BOTH tubes, not the 120mA you should see if each t...

The difference between plate to ground and cathode to ground, etc., is what you want, same deal across resistors,etc (i.e if plate to ground is 350V, cathode to ground is 20V, then plate to cathode = 330V, etc.)....that way one probe is clipped to ground and you are only handling one at a time so yo...

another good option is a tube extender, a relatively safe way to check voltages

[img:600:800]https://lh6.googleusercontent.com/-yuR4 ... 154911.jpg[/img]

The HV 650 VAC secondary has a center tap intended for use with a full wave rectifier...the voltage from the CT to either of the other terminals would read about 325VAC.

FWIW I've used connector bolts on some of my builds and they look OK and and work well, have seen them in lengths up to 5" or so...the large head supports the load well and the low profile is good appearance wise....big box hardware stores carry them. [img:400:400]http://www.homedepot.com/catalog/pr...

I understand what the ratings are about, my point was that running the transformer at a lighter than design load and PULLING LESS CURRENT will in some cases cause the B+ and filament voltages to run high in itself and that is what I am seeing...B+ is about 30V lower running 6L6's and filament voltag...

I was just looking through schematics too and the Valco Aztec is something that might work well in there too, and room to add a second channel. http://www.ampix.org/albums/bargainbin/valco_aztec.pdf Regan That would work fine. FWIW I changed mine to a similar Gibson GA-50 design yesterday and that ...

Interesting thread and I recently got educated on this myself when I converted an old PA amp from 6L6's to 6V6's...the lighter load made the B+ and filament supply voltages go too high so I changed the cathode resistor back to a 6L6 value and installed new 5881's this evening and the voltages look m...

Now that it's built (for the most part), it wasn't that bad. I work at a rather large power plant (coal fired), and we are in a very major outage, where we rebuild/repair/replace everything that needs attention. Along with this, there are some serious scrap materials to be had, if one is willing to...

Looks like this isn't the right catalyst, thanks! Not as is, but you could probably reuse the OT, buy a reverb unit PT plus a 6SJ7 and a 6V6 and build a 5C1 Champ for not too many $$$. The organ amps make great guitar amps as was said and I have two in the pipeline but they are not a good choice fo...

That appears to be a series filament amp with NO isolation from the AC power in....if so do not fool with it until an isolation transformer and three prong cord are added, as is series filament amps are dangerous and if a guitar is plugged in can put 120V on the strings...that could be very painful ...

I converted a PA myself recently and wired it like a guitar amp with a similar tube lineup and that worked really well...it is PLENTY loud and sounds great. Did not wire a tone stack initially and now I'm not all that motivated to add one, sounds good to me as is...but will eventually for the sake o...

very cool! I have an ancient prewar PA amp I'll be building along those lines as the tube lineup is similar and I'm a big fan of Charlie Christian so an EH series inspired build seems ideal...BTW a Cannabis Rex speaker might be worth a try, I used one in a Gibson BR-6F I rebuilt that was completely ...

Many of these old amplifiers can't be safely powered up without servicing them first. Doing the wrong thing can blow the transformers or worse, and then your find is a big doorstop. If you don't know what you are doing, ask. You'll get help. Remember, once you let the smoke out, you can't put it ba...

Looks like a custom build all right, late 40's to early 60's. May have been some band's PA amp. 50 pounds, I wouldn't doubt it. Tube gear ain't light. Good luck on your sales. Post a link to your ebay auctions or let us know your ebay name so those interested can follow the auction action, if you'r...