I am currently quite intrigued by tube driven overdrive pedals. Specifically the Kingsley lineup like the Jester or Minstrel. I’m curious to see if we couldn’t pool some collective tube amp knowledge and translate that into a pretty cool overdrive pedal / preamp. Some of my design curiosities / goals: Run a 12AX7 at proper high voltage. Keep things relatively simple to start. Trim bass early, probably with switching on the V1A cathode bypass cap to limit bass. Trim treble late with a Tweed style tone control. Have the ability to run this as a preamp and as an overdrive pedal into a typical tube amp. Incorporate a solid state boost before the tube to saturate it more heavily for more distortion. Have a power supply setup that doesn’t suck. Let’s address some of these one at a time. High Voltage In my research on tube driven pedals in general, I think there is a mixed bag. One main point of deviation seems to be whether or not the tube is running at what we in amp land would consider normal preamp voltages (mayb 250-ish vdc) or whether they’re starved. My assumption is that running a tube at starved voltages kind of defeats the purpose. However running a tube at higher voltages in a pedal format creates its own set of challenges. Mainly things like transformers, power supplies, and size. Take a look at the guts of a Kingsley Jester, for example: http:// https://medias.audiofanzine.com/images/normal/kingsley-jester-1152669.jpg I see what may be some kind of induction coil better in this picture: I don’t see any transformers. My assumption is that you’d need something that can take some sort of reasonable DC voltage on the input and convert it to both a HT 250vdc output and a 6.3vac filament winding. Here is a more recent picture of a Kinglsey Jester. I see some kind of PCB circuit on the bottom. Here is a picture of the Harlot’s guts - including another shot of what I believe is the power supply on the PCB at the bottom. I’m thinking a 12v input with a 20x winding ratio to produce about 240v on the output. Many tube pedals I see accept a 12v input with a pretty high current. Any ideas on how to power this kind of device?