Doug's Randall preamp

[RobBozic]

Hi,

Regarding the heads Doug built for Randall & in particular the preamp layout below

http://www.el34world.com/Hoffman/images/Ranpre.gif

Has anyone built this? If so, how much gain did it have compared to a typical superlead plexi?

Also in this layout there seems to be an error, the treble wiper connects to the B+ & 0.02 coupling cap of the V3 plate. I assume the treble wiper goes to V2 Pin 2, (a dwg error?)

Thanks
Rob

[sluckey]

Also in this layout there seems to be an error, the treble wiper connects to the B+ & 0.02 coupling cap of the V3 plate. I assume the treble wiper goes to V2 Pin 2, (a dwg error?)

I agree.

[RobBozic]

I was watching the Allman Bros. DVD from 2003 & Derek Trucks is using this amp & his tone is really clean & pure.

I was thinking of converting a JTM45 to this preamp & maybe playing around with V3 cathode resistor, maybe 10K unbypassed if there's too much gain.

Still, I'm hoping someone has built this to see what their impressions were of the preamp

Rob

[topbrent]

Here are some absolutely great clips of Derek Trucks from the 2003 "Live At The Beacon Theater"

&feature=related  "Rockin' Horse"

&feature=related  "Desdemona"