I was wondering if anyone has a schematic for the MXR distorion + pedal that shows which pins are being used by which components. i have a scheme from R.G. Keen but it does not have the pins numbered. please help.
Have you seen tonepad's project:
http://www.tonepad.com/project.asp?id=2
If you want to know wich pin is which, you can do a search for the datasheet of whatever op amp you plan to use.
Suggestion to consider...
http://www.muzique.com/lab/sat.htm
I put the 'twangy bite' Saturation control on mine [didn't try others].
I found this little addidtion really helps open up the tone of the pedal, can increases output, and softens the harshness of the clipping, and makes it a more adjustable effect.
I just need someone to tell which pins are used for what. i know you dont use 1, 5, or 8 but the chip has two inputs and i do not know which one is used.
Look at this schematic. (http://www.tonepad.com/getFile.asp?id=4)
This is a good schematic and it also includes the pin numbers. If you follow the traces from the opamp, you will run into the components that connect to each pin.
Here's the datasheet, pinout is right on the first page:
http://www.national.com/ds/LM/LM741.pdf
Watch the pot values, the tonepad ones aren't the best! Search for the article "MXR Distortion Plus Questions" for more info.
Factory spec is 50k log for Output (volume) and 500k rev. log for Distortion. You can go up to 100k log on the Output for more volume.
For each a single OA output, there will be - [neg] and a + [pos] input...marked on the schematic ... in the triangle [the opamp] look for - and + signs.
Match these - and + input signs to the OA - and + signs.
pin 2 is the inverting input on a 741 [single type] or -
Pin 3 is the non- inverting