The Amp Garage

Absolutely beautiful work!!! Thanks for contributing another awesome amp to the DIY community. Looking forward to clips and your thoughts about the amp.

Absolutely beautiful woodwork-the cabinet and guitars!!!!! Now since you learned how to build the ODS amp here, how about helping us learn to build the hardwood cab and guitars to match. If only I had the time. BTW, the amp sounds very nice and really enjoyed your soulful playing. Thanks for sharing...

I always tape the section I'm going to cut, draw my line on the tape and then cut with a fine toothed blade. Comes out very clean.

Thank you so very much Gil and Billy!!! You are most generous.

The Heyboer guys were great to work with. Call and ask them regarding the Mojo trannys.

Great question Normster. I completed my build with a 100 watt Marshall Plexi output transformer and Fender 100 watt PT from Heyboer. I followed the Hybrid A, non HRM OD and the 97 PS. It was Dumbley sounding, but rather aggresively so with mids being a bit in your face and not a very smooth transiti...

MarkB thanks for the clarification between plate voltage and bias voltage. Aiken's articles are great reading, I just forget I read them sometimes.
Dogears said,

I knew what Robert was really asking.....

Now if everyone else could just read my mind.....

The great oracle from the east said: You should not have 30v difference between V1 and V2 unless you are running the 97 schematic with maybe 12k between them. You are right -- pretty damn amazing!!!! I need a better supply of 2 - 3 watt resistors to tweak it closer but it is interesting how it sound...

I have recently been interested in the bias on the preamp tubes. At Dogears suggestion, I hung a 150K resistor off my power supply dropping resistors at the B5 node to simulate the load from the FET circuit. This dropped my voltages after a little resistor adjusting on V1 to 165 and V2 to 195. I rea...

I am equally frustrated by my CS 1955 Strat OD tones. Cleans aren't bad though. I figure you just can't have it setup for both. However, I would like to play with a Humbucker/Strat switch around the OD entrance. I tuned my amp with humbuckers and as I recall found some resistor values to be way over...

I apologize Gil for the error. I have collected many articles regarding Dumbles especially from Ampage. Several of the forum threads from their archives had conversations with you in them. Seemed like you were the most knowledgeable at that time and I must have assumed you wrote it. Anyway, my inten...

Here's a great read by the very knowledgeable Steve Ahola written some years ago. It has some of the circuit evolution of the Dumble amps over the years. It should answer some of your questions. I think this is in the Dumble files section but couldn't find it.

Gil,

What a wonderful surprise to read about this AM!! Loved the analysis and pictures. As always, Thank you for sharing!!

Robert

Hey Norm,

I always loved your earlier layouts and used them to design my boards with. Thanks much!! Its also nice to see some of Dogears knowledge put on paper. I notice you didn't include the 4M7 resistor to ground after the 300pF treble cap. Any thoughts on that one?

Scott,

What is the dropping resistor on V1 you are referring to?

Thanks!