This is the personal Mod I am working on (EMO MOD).
What I wanted to achieve is a DS-1 capable of function as a single channel preamp ranging from clean to usual high gain. I didn’t removed the R9 resistance due to that reason.. I added a 1k Pot to adjust pregain level. 10 k is over kill. I might try 2.2k before final assembly, but currently 1k good enough. The tone stack is currently very useful 47nf is too bassy for me so I went with 22 nF, I had the inspiration from numero6 and other resources as well.
For clipping alternatives I go with Reverb’s transistor clip and Wampler JCM 800 mod.
I found out that Red LED combinations compresses too much and reintroduces fizzyness I want to get rid off. Green emphasises mids. Yellow a more high mid. Blue LED’s is the best for tube like clipping.
My main 2 clipping mods will be no diodes and IRF530 mod I experimented. For the third one I will make 1N4148 and 1N4001 in series combination. I have to check out LEDs in low gain setting if there is a meaningful clipping otherwise I will have one no diodes position in the switch.
UPDATE: One position will be No Diodes and for the Third one I find a rather interesting solution. 4X 1N60 in PARALLEL for D4 and 4X1N4001 in PARALLEL in D5 position.
Serial Connection is for Marshall and Vox Lo vers,
For Modern Hi Gain I found Parallel is the Key, and LED s clip too much especially RED LED.