In the April issue of Elektor, there is a guitar distortion article derived from the Ibanez Tube Screamer. The input and output buffers are removed to simplify the design, which is the general idea I used for the AMZ Son of Screamer. They also made a few other changes to the Ibanez circuit.
However, there is a mistake on the schematic in Elektor.
The R5 resistor is shown connected to ground and it should not be. The resistor should connect the plus input of the second opamp stage to the 4.5v bias supply (not ground). This will provide the correct dc balance to the opamp stage so that it will work properly. I cannot tell from looking at the magazine whether it is correct on the pcb or not, but I would expect it to be correct since they have tested prototypes.
If you decide to build from the schematic in the magazine, be sure to make the R5 correction.
It’s a nice article and I encourage you to pick up a copy of the April Elektor at your local newsstand.
Alternatively, one could simply omit that resistor altogether.
>>>Alternatively, one could simply omit that resistor altogether.<<< As I did in the S-o-S regards, Jack
I’m surprised that no one has commented on the bypass method used in this project. Definitely not true bypass 🙂
Bypass is interesting. Looks like the tone circuit would still work.
did anyone build this http://www.elektor.com/magazines/2002/june/tube-box.55713.lynkx pretty another elektor distortion? mine doesn’t work 🙁