Brown Sound Princeton Reverb

[peckjed]

I stumbled across this and was curious if anyone knew what was going on. Sounds pretty good.

http://www.krusekontrol.com/fender_mods ... ton_reverb

[pompeiisneaks]

A wild guess would be it is a VVR setup for the amp.

This allows the user to lower the B+ voltages down which replicates the Brown Sound of eddie's where he used a variac set to like 94Vac on the input to lower the B+ on the other side of the transformer.

~Phil

[ViperDoc]

I saw Dave Friedman describe also that when EVH variac'd his B+, he would also rebias the tubes to proper plate current. Double-whammy.

[pdf64]

I saw Dave Friedman describe also that when EVH variac'd his B+, he would also rebias the tubes to proper plate current. Double-whammy.

Assuming the bias was suitable at 120, it already would be fine as the variac was dialed down; and, to a limited degree, as it was dialed up. Because the bias and HT supplies are inextricably tied to being ratios of the wall input voltage, and hence will track it, thereby maintaining a reasonably consistent conduction angle.

Regarding the brown sound mod, from the absence of any noticeable reverb in the clip, my guess is that it may repurpose the reverb circuit.