Once upon a time a guy on TDPRI pulled a boatload of 12FQ8 tubes from a Wurlitzer organ. They’re pretty odd tubes – Think of it like a 12AX7 with both cathodes tied together, and each triode has not 1, but 2 plates! He graciously sent me a half-dozen to experiment with. This is one of the projects that spawned from my experimentation.
This started out as someone on TDPRI asking for some enlightenment on what the various components do in a 5E3… before I realized it I had described nearly every component! Here it has been consolidated and reordered, along with a copy of the Weber 5E3 Deluxe layout that was used as reference.
I had been wanting to try an octal preamp for a while, so I figured 2011 would be a good time to build one. This amp has gone through about a dozen revisions with tons of experimentation along the way. After 2 years without major modification, I ditched the cascode and moonlight tone stack on Channel 2 in favor of a two-stage design. After a ton of trial and error, attempts at all sorts of interesting preamps, the current “final” version squeezes roughly 50 watts into a chassis smaller than your typical 18-watter. It was quite a challenge, and it’s...
The idea behind the Revibe is brilliant: Take a standalone reverb unit and add the two-phase “harmonic vibrato” found in the 6G12 Concert. I first built this Revibe in 2010. I bought the fiberboard and power transformer from Weber, and used my own components for everything else. I modified the layout to fit a narrower chassis by relocating the power filtration section to a ‘doghouse’, but all the fundamental orientations remained the same as stock.