i recently got a request from a mate about putting together a phaser pedal that he really wants, he had done some hunting and found this schematic to go along with it. i've tried turning this schematic into something workable but im definitely getting nowhere. just wanted to post here and see if anybody can help please!
This would be quite large but not too difficult to draw compared to some other circuits.
Now on the schematic..
Never seen this pedal before (not many infos) but I've found this:
http://www.effectsdatabase.com/model/sears/phasingpedal I assume "Q" is the Depth pot?
Are the original ICs LM324?
Do you know the original FETs?
Are diodes 2 - 6 1n4148?
I assume points marked 1.8V get connected all together (same thing for +6)
The Toe Switch numbering is not very clear.
I guess it's a DPDT like this:
I m currently not able to move much (injured leg) so i ll come back asap with move info. For now, i had found the transistor types in another forum but they were unobtainium. D4 to D6 must be 1n4148 since the voltage denoted on the junction is 1.8v (3x0.6v)
oh, and you re right, q is the depth / feedback.it comprises of trim pot that sets the maximum feedback possible (max when set to zero) and an external pot that allows manual control externally between the aforementioned max value and a min value that also depends on the trimpot value.
Also note that the fet bias trimmer value is missing but if the colour of the trimmers in the photo above is indicative of the value it can t be 1m since the q trimmer is 1m and the two trimmer colours are different.