Tube Amp Archive

Hey Overlandltd, Having built a few dumble clones (HRM, #102, #40, #Bluesmaster clean channel, ultraphonix High gain, and a John Mayer Sig clone), they all have different tone stacks; The skyliner tone stack is very typical Dumble glassy tone (#102), but more aggressive (glassy) John Mayer sig and #...

Hey Ales, Sorry for the late reply, it's been a busy september for me as well; To answer your questions : - Is having individual tone controls what you mean by "uncouple the two channels interaction"? No, if you take a look at the schematic (or the layout), you will see that the volume pots are both...

Congrats on your build, looks great !
Once you get the sting, it is hard to get off of it !
Cheers;

Fred.

Hey AleS, Great project ! I have now built three different renditions based on the "Tweedle Dee"; -1st one had silicone rectification, Cathode bypass + NFB on a switch and the rob robinette cascading gain mod. No low input, only high input and Lar Mar type 2 MV and FX Loop to insert time based FX be...

Yes indeed Bias tremolo.
Now you got me curious to taste the harmonic tremolo
Thanks again for the support, and this great community;

Fred.

Hey Sluckey, Thanks for all the input, I trully appreciate your help; I found the culprit : wired the bias feed of the rectifier tube ... but after the protection diode; No wonder I found the amp was missing bias : there was none ! :roll: Lucky me is using worn out tubes for all my smoke test... jus...

Hey sluckey, Thanks for catching this one ! Yes the cathodes are connected to ground with a 1ohm resistor; Vibrato is working indeed. Smoke test went well, nothing burnt or smelling wrong; Voltages are good but on the bias; I have sound but it feels like I have not enough negative voltage. Will try ...

Amp is finally all wired up ! The build process was challenging as the tubes layout is not ideal to manage efficiently cable runs. Hopefully the amp will remain quiet. I have used a known grounding scheme that worked very well in my previous Tweddle Dee builds. The remaining questions is : will the ...

Been moving slowly but got to get together the preamp board PXL_20250518_204042140.RAW-01.COVER.jpg And finishing the heaters as the donor would not leave me many options PXL_20250518_204008470.RAW-01.COVER.jpg Ran out of eyelets for the power amp board, order is on the way PXL_20250518_204125035.RA...

I would add that using a D-Lator on my dstyle builds adds volume significantly. And when that input gain is maxed, I get distortion, which is normal. Try and clip an alligator cable bypassing the resistor/ capacitor, and play. Listen to what the network does. IF I remember correctly, the network wou...

So I see in the schematic you are using a DC to DC high Voltage converter outputing around 300VDC. I am really curious to understand if there is any effects on the B+ vs a beafier toroid transformer that would get the secondaries up to 300VDC. Have you messed around with these DC to DC HV units befo...

Hey dmoose5835, Your layout references a Hammond PT 1182L6. How will you get the B+ voltages inline with what is expected dor a D-style amp (200 to 235ish VDC on the plates)? FYI I have built a badger rack preamp that works fine with a Antek AS-05T200. Where do you get uour PCB printed? Thanks; Fred.

Hey Dmoose5835, Very interested with your PCBs. I am switching over to rack preamp builds. Amp are taking too much space, and Dumble power amp sections re very redundant; Where do you get your PCBs printed? Do you have a reference for the connectors on mouser? Never used any of these and dont know h...

Here are a few pics of the donor Symphonic amp. Originally a stereo tube amplifier with single ended 6V6s, tube rectifier, two 12AX7 and a third smaller tube for tremolo. Probably 2 x 5 watts output judging the size of the small OT. 3 inputs and a pair of RCA jacks as speakers outputs. PXL_20240819_...

Hey guys, Another Tweedle Dee build is on the way! I want to assemble : - a single bright channel - with cathode bypass and NFB as provided on Rob Robinette's website (I love this feature that really extends the palette of the 5E3); - Dumble PI cathodine (with Lar Mar type II Master Volume and 470k ...