With all the fun we had with the AC10 amp, whether it was a hybrid or not because it had some SS devices in the signal chain I thought I thought, what would I do with a two tube limit in a hybrid amp? I picked two tubes as I wanted to keep it relatively compact, almost a large pedal format. I have a PWM amplifier board to use along with a DSP chip to do the reverb. So it is the preamp section I really had to work on. I thought of whether to use a pentode in the circuit, to use a Marshall (or 5F6 Bassman) preamp circuit, in the end I thought I could get the most mileage (yummy distortion) using the second stage of the Marshall/Bassman amp, gain stage and cathode follower, along with the phase inverter section. Some amps with a master volume have it after the phase inverter just to get its contribution to the sound. And since different phase inverters also have different sounds by the way they are biased I added a switch to change between some standard resistor values. Another thing that I did was to add a switch that changed the signal level on one side of the phase inverter output to give an unbalanced signal to the summing IC. The other side of the two pole switch will switch a bypass capacitor on the input stage, without it there will be some bass rolloff. That is when I breadboard the circuit and find the right values. Might be a little while yet, I used to think up circuits when I did not feel up to actually building something, I have a ukulele on the bench now that needs to be completed. But I did want to build a pocket sized amp this winter so this is not just a paper exercise. I thought of a lead switch and using a triode as a stage of gain but did not want to give up one from the other stages. In the end I thought I could just drop down some of the signal from the normal pot and bypass it with a lead pot. The inline cap will roll off some of the highs. I wasn't sure if I should go with a standard volume control arrangement or as a variable resistor, decided to go different. The schematic shows a switch but eventually it could be a relay or some FET's to control the switching. So here it is, anything but a finished product.