Small portable, really portable practice amp

[Guest]

[quote author="Ptownkid"]Ok, so i built two of these guys, and all I get out of them is distortion, or a lot of distortion, there's no cleanish tone at all.

Also, when you pluck a note, it hardly sustains at all and then quickly crackles off into nothingness in the blink of an ye, it's like it's got a gate.[/quote]

leave out the 1k pot or 5k between pins 1 and 8.

for just raw clean power, try just a bare wire between 1 and 8.

 

[Ptownkid]

that's the part I don't get, if you listen to the sound clip for the little Gem on runoffgroove, it's a hell of a lot cleaner.

I'd still like to understand what causes the gating.

 

[PRR]

> all I get out of them is distortion, .... it hardly sustains at all and then quickly crackles off into nothingness...

Some stage is mis-biased. Without looking at the schematic, I would expect all R-C coupled stages to have a plate voltage very roughly half of the supply voltage. 0.3 or 0.8 might be OK, but 0.1 or 0.9 is dubious. Could be a wrong part, a bad part, a misconnection, or a sick tube. The transformer coupled output stage should show reasonable cathode bias (find the datasheet for the tube).

 

[Guest]

ive built a few.

you should get some clean tones out of it with the "gain" turned all the way down....

i think prr is right...something must be wrong with your build.