I plan to wire the Normal Channel per the schematic with Martin Manning's 350k tapped pot alternative. For the Bass Channel, I am thinking of taking Roe's suggestion of going with a K50 preamp. Power supply caps will be 2x80uF F&Ts in series with 220k balancing resistors for 40uF 600V and the rest 22uF, solid state rectified.
Questions for general comment:
1) Thinking about adding a trimmer for the PI. It is interesting to note the rather large difference between inverting and non-inverting plate voltages (+20V). Perhaps this is part of the Bassman magic and should remain left alone, or maybe it could benefit from some Dumblizing?
2) The Presence circuit is 4k7 || 0.1uF-25k pot. Was thinking about going with the older Marshall 5k pot and 0.1uF as the sweep is much more effective.
3) Chassis has a hole for a second bias pot. Might be useful to be able to be able fine tune each power tube and especially in conjunction with a PI trimmer. Again, not looking to add complexity unnecessarily but it could be useful.
Starting to assemble this weekend
![Cool 8)](./images/smilies/icon_cool.gif)
Cheers, guys.