Tube Amp Archive

Well ........................ passed the smoke test! But........................ no sound :( Weird.....................High pitched between a squeal and a hum barely audible but changes pitch as you move the master / level pot. Also changes pitch as you manipulate the bias pot. I know that the sque...

Thanks for the insight guys. Decided to scrap the DC heaters... Going to use some Iso trafo's too. I believe I'm implementing this right? can you actually isolate the whole circuit from the other? haha way you're doing it, you're separating the circuits by using green grounds and beige grounds. how...

i have 6vDC heaters on my dumblator. the transformer came with 6.3vAC filament taps, and I had them wired to the heaters in AC before, elevated by about 30v. I didn't have messy wiring or anything, but it hummed pretty bad. changed it a little, now using DC heaters and it is very quiet. I also do no...

the DC power jack is there because it fits there. you can't put the in/out jacks with the footswitch in the middle. however, the DC jack fits next to the footswitch in the center.

okay I'm going to get the Hammond PT, and figuring for 125VAC supply at my wall vs the 115 supply the PT expects, here's what I'm going to do to put 340V and 280V on the two supply nodes (got these values from an old schemo by structo, I think). I assumed 1.8mA for the CF since that was about what ...

availability, could you clarify? You are using a full wave, the rectifier at bottom left of the pdf, not a full wave bridge, right? I'm not sure what you're referring to when you use the term 'voltage doubler' http://www.hammondmfg.com/pdf/5c007.pdf I was planning to use the FWB and tape off the ce...

This looks like it will work with a FWB and AES has it for $40 where Mouser it is unstocked: http://www.tubesandmore.com/scripts/foxweb.dll/moreinfo@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?item=P-T261C6 250VAC CT, 50mA, 1A 6.3VAC Yes? i have this one, and although it measures 1.5" wide at the narr...

im not an english major, but i just want to say tony's dumble sounds quite amazing. you can market the technique whenever you figure out what causes that!

any preamp can clip. as long as there is a huge sound presented at the grid. but if the preamp doesn't clip, you can just limit the signal going into the output tube grid (resistor in series with the master volume) so with the master full, it's actually not full volume. then the power amp will never...

just to be clear, do you have tubes in there?

To start it off, the amp I am working on is not a Dumble clone. It is a Dumble inspired single channel amp with three gain stages. I really like the tone that's in between the famous overdrive tone and the sparkle clean tone, with a strat's neck pickup. and I believe the three gain stage design can ...

you're going to use variac without the tubes installed right? check unloaded heater/HT voltage, it'd be a little bit higher than the desired voltage but thats ok. set bias before you put in tubes so you don't have to worry about red plating anything. right?

on spec, your transformer should be seeing 117vAC, and you're seeing 124vAC (6% increase). transformer is out of spec by a bit too much, being 7.7vAC (which is off by 20% or so). heaters want to see 5.8v~6.9v, at most 10% from the 6.3vAC norm. I think 7.7vAC is a bit too much. 330mA is 30mA higher t...