Parallelyzed...hmmm...

[mydementia]

I've been contemplating a simple buffered loop selector project for a while now and decided to throw everything together to see what it did.  My basis was the Parallelyzer from GGG (http://www.generalguitargadgets.com/index.php?option=content&task=view&id=94&Itemid=122)
Here's what I did:
Simple 'A or B' DPDT switching w/dual color LED->Input goest to either Buffer A or B->Buffer A goes to Send 1, Buffer B goes to Send 2->Return 1 goes to 10k mix pot 1, Return 2 goes to 10k mix pot 2->Pole 2 of mix pot 1 to mixer input 1, Pole 2 of mix pot 2 to mixer input 2.

I made this dual buffer layout from the single buffer at GGG using banika's layout program  - pretty cool.  The idea was to make this a dual buffer module to build a 2, 4, or whatever even number of buffered parallel loops. 


I ran this into the mini-mixer found in Torchy's archive (here:http://www.indyguitarist.com/torchy/). 

I got everything wired up and plugged in to find that I can mix two looped signals like a champ...but I can't A/B the loops...
I've been soldering a lot tonight...can I just install a switch to toggle between outputting through the mixer or going straight out?

I like the idea of having a single stomper to select between a jangley/echoed clean sound and a raunchy Dr Boogey'd/flanged sound...just have to figure out the mixer...

Thanks for looking.
Mike

[metal god]

Isn't pin 4 supposed to go to ground?

[Connoisseur of Distortion]

...

I think metal pretty much nailed it...

[mydementia]

Yeah, yeah - I missed that one on the redraw - the image is correct now.  I originally built the buffer section without R5 and R6 (not sure why I didn't think they were important...) - I figured there was a problem when I was measuring 1.3V on my TL072 pins (1,2,3,5,6,7) instead of 4.3V...  I realized while I should have been sleeping last night that I created a voltage divider when I tried to incorporate R5 and R6 into my layout - I used one 2m2 resistor branching to both input caps - dumbass!  I split them up this morning and now get ~4.3V on the TL072 where I expect it.  I also put in a DPDT on the 'return'.  My thought was to run switch side A directly to the output jack (for one loop at a time selection) and B into the mixer section.  When I fired it up, it seemed like the buffer was doing what I originally thought it was supposed to do and that I need to remove the DPDT (switch side A didn't do much).  I need to do some more verifying tonight (darn day job) but I think all I have left is to put in a 'both' switch to push both loops through the mixer...then I'll be parallell processing to my hearts content.

Any thought how I should put in this 'both' switch?  I'm thinking I'll loop the guitar input signal to the center pole of another DPDT and run pole A to both buffer inputs and leave pole B open (DPDT will let me use another LED too).  I haven't had much coffee yet...does this make sense?  Is there a better way?
Mike