Tube Amp Archive

I do believe that you gentlemen were right about the wiring being wrong but when I tested the output transformer and it was bad. I replaced it with the Hammond as recommended and went through startup. Checked the bias and I ended up changing out the cathode resistor to a 250ohm and it has a calculat...

Apologies, I didn't see that this discussion went to a second page and you had already answered this question. I will get a replacement and get this project completed. Thanks again for your amp information

Steve: I took on the Dual Lite project and got it all assembled. It has been a fun project and great learning experience. Please see picture. I used Rob Robinette's startup procedures and found that there is no DC power at v5 pin 7 where the output transformer connects. Pin 7 at v4 is 472 v DC. By t...

Thanks for the recommendations. I have previously built a 18w tmb and really like both sides of the amp. I am also intrigued to have an AC15 side of the Dual Lite that Sluckey recommended. I looked at the schematic and layout and it looks to be in my wheelhouse. The layout includes a PPIMV which I h...

A while back I salvaged a power transformer and output transformer from an old radio console. I posted to here to ask for help identifying the transformers and had a few responses that indicated the transformers were likely from Ceco Manufacturing. The console looked like it was probably from the 19...

I was at a property recently and saw an old radio console in the junk pile with tubes and transformers showing. Turns out it had el84's and two Mullard 12ax7. The transformers look to be in good shape but don't have any name or label to identify. There are numbers on the bottom of each but a search ...

Thanks for the reply. Maybe I am just surprised by the power of the amp and a linear pot for the master volume may be a good next step to get better control. I play a Gibson 335 which give a ton of bottom end. I tried a Tele today and it sounded really nice. The layout and mods are attached. These a...

I recently built a 5e3 as my first build. I used a small parts kit from Mojotone for most of the electronics and used Classic tone transformers. Also included several Rob Robinette modifications including a negative feedback switch, a pre-phase inverter master volume and rectifier diodes. I used RCA...