Sorry took a while but here is some answers
1. the trace between Q1 and R36/R37 must to be cut under C16 or under R29 (
http://solderman.fatabur.se/ada/ADA%20Audio.jpg)? I am almost sure that it must to be cut under R29, but...
-Correct. You may cut trace and the connect a wire from D on Q1 and one on R37/37 and have them to a switch this way you can switch in and out the Threshold Pot.
2. you said "There is a no pad for the wire for the Vb to the Enhance pot on the Audio PCB". I don't understand anything...which is the "Enhanced pot"?
-Yes P1 is “Enhace” lug 1 goes to Vb. There ought to be a pad there where it says P1-1 on the audio part.
1. maybe I'm stupid, maybe I'm too tired, but I can't find R62 and R68 (47 ohms both) and D7 (a 1N400x)...
-R68 is in the LFO part next to the 4007. I have removed R62,55,C26,22 40 and D7 cause they are not needed. C4 is swapped to 100uF. R77 is added as a current limiting R for the status LED.
2. which are the values of the R70-2 and R71-2 (I think that they are for MN3207)?
70-1=1K
70-2=14K
71-1=14K
71-2=1K
3. Charlie's instructions have the last resistor labeled R73, so which are the values of R75 and R76 that you added (and I
-suppose that you have no R74 because I couldn't find, too)?
R75 and 76 are both 68K they are for the IC2 Vb bias. There is no R74 don’t ask me why
4. Charlie's instructions have the last capacitor labeled R40, so which is the value of C41 that you added (I hope that's the only one that you added)?
-C41 is a filter Cap for the IC2 bias 10uF
5. who is your IC2 from the Audio PCB (in Charlie's instructions it's indicated as TL074, but it's too small for that...)?
-It’s any dual Op-Amp TL072 etc. for producing Vb bias to the audio part and separate the Vb bias from the LFO to avoid LFO ticking.
6. can you be a little more explicit regarding the jumper from the "Manual" pot (I want to have it externally, but simple...without an expression pedal)?
-Well, I don’t really understand since the P3 on the LFO part IS an external “manual” pot and to have it that way jumper the pad from lug 2 to the pad that goes from under R50.
Pleas get back to me if you have further questions.
PS.
I have Emailed you some pics hope you are on a fast link :-)