These are mods I have done on several customers Boss DD2 or DD3 pedals to obtain a more realistic tape echo sounding device.
naturally - only a tape echo sounds like a tape echo
the schematic can be found here:
http://www.freeinfosociety.com/electron ... php?id=126
Please note these mods apply to the original DD2 or DD3 which used the 64 pin DIP controller IC.
If anyone is sufficiently interested, I will post the mods for the later model SMD postage stamp controller IC model.
Okay - here we go
1: replace R14 (33k) with a 10k resistor.
2: replace R33 (47k) with a 22k resistor.
3: replace C26 (1uf 50v) with a 10n film capacitor.
4: add a 100n film capacitor in parallel with the effect level potentiometer ( between pin 1 and pin 3 of the poti)
That's it
bajaman
ps: check out that nice input buffer too.
This mod for the DD3a...
This mod for the DD3b...