Tube Amp Archive

Unless you are driving the tube to the point of a square wave, it is unlikely to sound "bad" for preamp tubes, because there is usually a whole bunch of tricks after the fact to take care of the fizz. In the power amp, the output is THE output, and any stray harmonics are going to be noticeable. Als...

The "grey cap" in the pi is a trim pot used to set the bias resistor to taste. I will be taking them out once I tune them properly. Some parts of the amp construction do look sketchy, but I have traced everything, and there hasn't been anything to indicate problems. I will be redoing aspects of the ...

There is no theoretical reason, but for guitar amps, there is a big trade off in sound. Usually the hard upper limit for grid stoppers is determined by input capacitance, but for most power tubes this is no bigger than any of the preamp stages. The corner frequency with 100k stoppers should still be...

Here are the guts, just for the hell of it. I intend on cleaning up the wiring, but seeing as it doesn't seem to suffer from parasitic oscillations or noise, I am not too concerned. [img:2592:1944]http://i.imgur.com/2o6VXlf.jpg[/img] BTW the finish on the chassis is engine turning using a scour pad ...

The schematic is shown below for the CF and PI; the originals are actually hand drawn and virtually illegible. Note the tonestack is missing, as right now i is bypassed in an effort to supply the PI with as much input as possible. [img:909:740]http://i.imgur.com/cnxTYu4.png[/img] I may have used (re...

Hey everybody, long time lurker here. Just finished this earlier today. Here is a peak. [img:2473:1041]http://i.imgur.com/FoJg8rU.jpg[/img] The preamp is basically a couple of garden variety 12ax7 triode stages feeding a two knob EQ (similar to Big Muff tone control, but with a variable mid scoop), ...