Introducing the Frog Tube Preamp. It is based on the Fender Dual Showman preamp section from the late 60’s and inspired by the iconic 1970’s era Alembic F2b preamp based on the same circuit.
The Frog, guitar Tube Preamp F1a is based on the 1st two stages of the Fender Dual Showman, using exactly the same tube preamp circuit like the iconic Alembic F2b Preamp. Its unique because it is pounds lighter and fits in a small pedal enclosure that can snuggle up with your other pedals on your pedalboard. These are a few sample builds:
Because of the unique power supply, it is very small, and can fit in a standard Hammond style cast aluminum enclosure 1590BB. It runs on a standard 9-12 volt DC wall wart transformer. The power supply, using very little PCB real-estate, pumps up 9-12 volts DC to 185-200 volts DC. So, that means the 12Ax7 type preamp tubes run in Class A, so there is no “starved plate” in this preamp. It is a very low noise power supply which means it is a low noise preamp! The tube heaters are run on filtered 6 volt DC regulator as well.
Also, I have added a Hi-Cut capacitor that can be switched in that will give you a little less of the high end, emphasizing the the mids/lows. The other change is an optional diode clipping switch and diodes that can give you a little bit of that overdrive/fuzz sound. Again, completely optional.