Tube Amp Archive

Most people insert a pot to vary the series resistance when experimenting with GNFB level. It's hard to do anything stupid. You can play with GNFB and change rectifiers to your heart's content. Just make sure your PT has sufficient current rating if you try a 5U4, and reset the bias for each rectif...

My WZ34 has a series pair of 39ohm internal resistors to simulate sag. That drops far more voltage than a real GZ34. In an amp, it drops the power output perhaps 25%. A GZ34 is better simulated by a 22ohm resistor. Guitarists use the term headroom to refer to both sytem power output and system gain...

… Can a 500V voltage rating capacitor be used for the A/C shunt capacitor … Which particular component is being referred to by ‘A/C shunt capacitor’? … I think with a Weber Copper Cap solid state rectifier, adjusted bias and a 100R NFB tail resistor the Vibroverb will have a little more clean headr...

1 - That layouts should be fine. Spreading it out a little bit shouldn't hurt anything, condensing it might. Low gain though, so less worry. 2 - If your PT doesn't have a center tap for the filaments, you must use two resistors for a virtual center tap... No matter what power tubes are used or how ...

Hello TAG...:mrgreen: I want to build a Blackface Deluxe Reverb (current project) and a Blackface Vibroverb (next project) AB763. I want the amps without the vibrato on the reverb channel and a mid control added on both channels tho, thx to Rob from robrobinette.com that was quite easy! I also upped...