Hi there !!
First a couple of word about myself, as I'm new to this forum.
I'm a norwegian mech. engineer and guitar-player, running my own tube amp repair shop on hobby basis.
I've been posting on the Weber amp building forum for some time now, and I'm responsible for the last ReVibe revision... (Called "the Tore T mod" on the Weber forum) 8-)
Let me explain how it works:
Changing V1B from a cathode follower to a "normal tube gain stage" brings up the signal through the vibrato cirquit to a level 35-40 times higher than in the original ReVibe design... Bettering the signal-to-noise ratio by the same amount... And bringing the signal level in the vib circuit closer to the levels found in the original brown Fender amps.
(I realized this after trying to understand why my '62 Pro was totally noise free without any shielded cables or magic grounding etc, while the ReVibe seemed to pick up tons of noise, even after lots of shielding and trying different smart grounding schemes... The signal level in the original revibe was BELOW the guitar output level, where it is amplified 50-100 times before the vib cirquit in the Pro...)
The R50 / R24 voltage divider brings the "vibrated signal" down to "normal guitar level" again, but it DOES NOT CUT THE VIBRATO LEVEL....! It even adds the possibility to tweak the overall gain of the unit, by playing with these resistors.
It's no magic at all, it's just bringing the operation a little closer to Leo Fender's original cirquit...!
It should be no problems to mod the Hoffman Layout to the modded schematic either....
The revibe still needs close attention to the wiring layout in the vibrato oscillator cirquit even with my mod, to prevent ticking, oscillation and "putt-putt"-noises... But hum and hiss is guaranteed to disappear with the mod...!
Good luck and best wishes from Norway,
Here's the link to the modded schematic once more:http://www.webervst.com/revibe/5h15_schem.jpg