I have been doing some experiments with super simple switching mixers that will make it easy to build a Ring Modulator Pedal without the diodes or doubly balanced Gilbert Cell mixers. Still working on the basic circuit but it should be very easy to build. More to follow.
I think the amp has better head room for high output guitar pickups and better overall balance in the tone, when I attenuate the bass a little and remove the treble boost. This means making C3 1000pF instead of 1uF and eliminating R29 and C30. The schematic below reflects these changes.
New schematic with minor changes in values:
Fortunately the layout remains the unchanged!
Gain distribution is tricky in this amp, partly because of the low voltage supply and the need to not over drive the FV-1. Some may have trouble with the first preamp being overloaded with hot signals. Increasing the emitter resistor R5 in the first stage and lowering it in the last R24 may help with this. The overall point here is that there is lots of room for adjustment.
Got a nice layout comming – hopefully some will be able to use it.
I am going to do PCB board layouts of some of these projects in using expresspcb.com’s free layout tool. I will use through hole parts as mush as possible. All the parts I spec will be available from digikey, mouser, mojo or small bear – no condor eggs! I will post the files and anyone who wants can mod the boards or order them as is from expresspcb. It will take me a couple of weeks – I want to be very careful and make sure I have no errors. So check back soon.