“I just thought I’d let you know I recently finished an amp based on the tweed Fender Champ (specifically the 5e1 and 5f1 schematics). Without your build documents for your WF-55 I wouldn’t have been able to get this amp built. That was my starting point, but I ended up developing from there slightly.
“The main thing was adding a TMB tonestack. I wanted to try and stay close to the character (and voltages) of the ’50s Champ though – not copy the later ’60s Champ with similar tonestack. So I thought I’d try out a Mosfet buffer after the first stage – doing the job of a cathode follower effectively – to try and prevent the tonestack eating up too much signal. I didn’t want to bypass the cathode resistor on the second stage. The preamp is more or less based on the section of the 5f6 Bassman preamp with the cathode follower – except I used a 47k slope resistor instead of a 56k.
“I’ve been pretty pleased with how this has turned out I get the warm, rough-edged clean sound I was hoping for. I also really like the impact the Mosfet follower has: it really brings the (much maligned) TMB tone stack to life. It’s something I’ll certainly use again.”