6v6 single ended guitar amp?

Started by Arn C., January 23, 2007, 03:55:05 PM

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Mark Hammer

I've brought my wee Princeton to "basement gigs" with friends, and although it had an extremely hard time being heard above the drums and rest of the band, that was largely due to the fact that it was an 8" in an open-back cab.  Something with more, and more serious conservation of, bass would have made it much more capable of competing.  Not cleanly, of course (anything over 6 on those "goes-up-to-12" amps is largely grind), but at least being easily heard above the din...or mixed in with it.

Arn C.

Firstly, thanks for all the tips and advice on this topic.

I took the amp apart and looked it over with the schematic and then I soldered some 1uf caps across the  cathode resistors to see what would happen.

Next, I started checking for any bad soldering.
The first place I started was the large caps from the rectifier tube.  I had to parallel a few caps to get the proper values.  One of the solder joints was loose.   I resoldered the bad joint.   

I put the amp back together and still kept the same cheap 30 watt speaker.   

Wow!  Really loud now!   I believe the power circuit was starving for power, that was not available due to the bad solder joint.

I now have only one more problem.  It now has a sort of fizzy treble sound now.  It has a sort of fuzz/overdrive going on but to hard on the ears.  If I  remove those 1uf caps I  put across the cathode resistors, would this help?

Thanks!
Arn C.

Arn C.

UPDATE:   

I just clipped the second stage cathode resistor paralled cap off and lost some of the fizz, next I will remove the first one and see if it is all gone.

Peace!
Arn C.

Arn C.

With both of those caps removed the amp sound great!!!!!!!!!!

I can see how those caps definately do affect the sound.   If someone wanted a bit more distortion, that would be the way to go.

Mess with adding different value caps across the cathode resistors.  Maybe put a switch to switch it in and out.
Once again thanks for the assisstance!!!!

Peace!
Arn C.