Re: JamMix - Headphones Practice-Play-Along Amp

Posted by MAO on Jan 03, 2016; 4:06am
URL: http://guitar-fx-layouts.238.s1.nabble.com/JamMix-Headphones-Practice-Play-Along-Amp-tp26681p26908.html

Corrected link Electronics Now - 10/1996

Follow up letter regarding the ICs and decoupling caps here on page 14 Elcetronics Now - 04/1997 

I think the 1458 is a better IC for this type of distortion/clipping, looks similar to the DOD 250 and MXR distortion+ type distortions which used the LM741. I believe the 1458 is a dual version of the 741.  Unfortunately the way I laid this out, the guitar signal passes through 1/2 of the 2 bottom ICs.

For this build, I ended up using 4 TL072s and a 1458 for the bottom right opamp.  So the distortion is happening around the 1458, but so is part of the right channel of the headphone signal.

If I were to build another, I would update the layout so only the clipping takes place around the 1458 (or maybe a 741 since only 9 or the 10 stages are being used), and the rest of the audio passes through the TL072s.

Not a big deal of course, as it's just a headphone practice amp.  

I'm also wondering if I could sub in the actual DOD 250 for the distortion circuit or maybe even a Plexi drive :0)    

Actually, it looks pretty easy to try, just disconnect the Level 2 wire from the pot and connect it to the output of the DOD 250. Might check that out tomorrow.