The Amp Garage

Well I tried it just like martin manning said, the overal headroom was minimal but the clipping characteristics were not great.. it was clipping in a weird non musical way.. could that be crossover distortion? With the volume higher, the distortion was heavier and sounded kind of decent with a lot o...

Great, I'll open the amp up as soon as I have the time and mess with it !! Thanks a lot !

Killing the signal on one side of the power amp means that output tube isn’t effectively conducting AC, so the OT primary on that side will not be in the equation of load impedance. (Transformers only transform changes in voltage/current.) So it's like changing the ratio of the transformer ? The cu...

What if I connect a 20uF cap from grid to ground? Wouldn't that sent the signal from the PI to ground and keep the tube at idle? I'm asking because it recures no modification in the wiring at all, so I can test it and see if I like it.. Then I could keep it or do what you said!

martin manning wrote: ↑Mon Apr 29, 2019 11:53 pm Like this:

Thanks!! Wouldn't that change the bias of the "disconnected" tube, because of the missing 220k resistor? That way it'll run cooler right?

That would work too, but it would also change (unbalance) the load on the PI. Then what do you suggest? Could you please explain me this again, I didn't get it :? To be clear, you'd disconnect it from the PI coupling cap, and connect it at the junction of the 220k's, same as the description in the ...

To be clear, you'd disconnect it from the PI coupling cap, and connect it at the junction of the 220k's, same as the description in the Ampbooks link. Wouldn't it be the same if you just used a switch to disconnect the PI coupling cap (or send it to ground?) from the grid resistor of the output tub...

From what I've read I think it's really bad to pull out a tube because then there will be high voltage across the winding of the OT and may cause arcing etc..

Hello, I have a Fender Blackface clone, an upgraded princeton, that I'd like to use in lower volumes and make it break up earlier for home use.. After building myself an L-Pad attenuator from guitar magazine, changing the GZ34 to a 5U4GB, and still not being very excited with the changes, I thought ...

I just noticed that with the reverb pot on 0 there's still some wet signal passing through :\

sluckey wrote: ↑Wed Dec 19, 2018 6:44 pm I highly recommend a dwell control even if you have to mount it on the back.

well I guess it'll help both ways.. lower reverb decay and make it a little less bright

However, with idle current at 9.5 mA the driver transformer is running about twice the level it would see using a 12AT7, and it may not stand that. It doesn't make sense to run that tube into such a high impedance. Could you please roughly explain me these? about the transformer and the impedance o...

any ideas where to create a simple high cut filter in the recovery section ?

jjman wrote: ↑Wed Dec 19, 2018 3:03 am I guess you got the 10watt tranny or still 3watt?

I got the 3.5W tranny, the plate to cathode voltage is 360V and with 9.5mA current the power happen to be 3.5W.. I'll try it in high volume after and if it cold clips I'll bias it a bit hotter.. saddly I don't have a scope!

I just finished it and it sounds very nice, it got potential but needs some tweeking.. any ideas how can I darken the reverb tone at the recovery stage? I tried some caps at the 1n-15n range from grid to ground, as many suggest but it didn't help at all, it made it sound like a horn with the standar...