When I first build this there was alot of layout errors and a wrong resistor value, here are my findings and how they make this layout like the original SansAmp.
EDIT: Added layout here for reference.
http://4.bp.blogspot.com/-giA-7d3plvs/VknwbkJdygI/AAAAAAAAALs/nG6zm4IiMTo/s1600/SanClassic%2BCuts.pngFirst the 10K resistor (was 100K in the schematic) on pin 7 of IC2 is wrong, I found this out by the layout Alex made with the Kurt Cobain settings/no DIP switches. With those settings on an original where you have Amp Drive & Presence Drive all the way off it would be like a cleanish booster, but with the 10K in there on
the layout it would distort way too much. A 220K resistor should replace that 10K (100K) and it will sound like the original.
And the errors on the layout are Amp Drive & High pots are wired backwards which means when you have the DIP Sw 11 to Amp Drive lug 1 it won't sound like the original, DIP Sw 11 should be to Amp Drive lug 3. The High pots just worked backwards so High lug 1 should go to Output lug 3 and High lug 3 should go to the pin 13 junction of IC1.
Lastly, again when I made the Kurt Cobain settings layout that Alex made, I found that the layout didn't sound exactly like an original, there's alot of high end fizzle that can be tamed by adding a low pF capacitor between pin 13&14 of IC1, I mention
here that I went up to 330pF and still sounding like an original. So, maybe a socketed one to test out what works here would be best.
With these findings you should get a clone of the SansAmp Classic.