Tube Amp Archive

I used 350-0-350 PT and a 6K6 OT transformer - both Hammond. I am in the process of getting a hold of "Hot Blue Plates". I crossed paths with him on the Chetboard a while back - so we will see what happens. I still would like to find out more information about why the tone stack is setup the way it ...

I do agree - the 270K plate resistor and the 620 ohm cathode resistor is strange and that puts the bias towards grid current limiting conditions. I did change that resistor, I think to a 2.7K to bias it more towards the center. I think we are talking about different schematics. I have seen the "napk...

One other piece of information that I thought I would throw in here is that I do have a reissue Stanel 25L15. It is one of the early ones with 6550 output tubes and also reverb and effects loop. Yes the circuit is quite different - but it still sounds really great. Now when I push the amp around 6 o...

Thanks for responding guys! Cameron - you drew that schematic that I attached? Am I hearing you right? What was your affiliation with Bob Crooks, the way you speak of him it seems that you worked with him. If so - maybe you could tell me what is going on electrically with the 12AT7 - that tone stack...

Hey Fella's, I will start off by saying that I am a huge fan of the Standel 25L15 guitar amplifier. Almost everywhere you read, you will find that everyone says that the 25L15 has amazing cleans and unbelievable headroom. I have built 3 of these amps VERY similar to the hand drawn schematic that I a...