paralooper with bazz fuzz

[sean k]

Heres what I built and it works but needs some improvements


The section on the return is just R.G's A/B just pasted in and it seems as if theres not enough gain on that side.The bazz fuzz and anything on the loop has to up full to get a balance and the loop just bypassing the original signal is barely audible.I haven't checked all the resistors,theres a chance I may have put the wrong value in somewheres,except for the 470k on the send which I thought might have been 47k but its 470k.So its either a wrong resistor or pasting in this circuit just wasn't a good idea.Oh,and the 1M in brackets in opamp A is a slight improvement but only on one phase.Any ideas?

I've also put together something in the bottom right corner which might work and is an idea from the Brass Master but I'm not sure if it'll work with fets and will have equal'ish outputs off drain and source.Comments please and anything else I could possibly use?

[idiot savant]

i just built a bass paralooper on perf using moose's layout, if you look at the layout vs. the schem, you'll see that the lone gain stage is that last opamp before the output, as drawn on the schem it has a gain of 2, looking at the layout r12 is changed to a 100k for a gain of about 10, so you could up that 10k in the feedback loop of the last opamp to a 100k and add some more gain to that last stage to make up for losses in the filter, and phase splitter. mine has plenty of gain on tap, and i use it as a boost with good results. hope that helps.

here's the links to compare...
schem:
http://www8.plala.or.jp/KandR/cir_bassthru.html

layout:
http://www.moosapotamus.com/paraloop/bplLayout.gif

[moosapotamus]

Cool!
Ditto what the idiot said... add the gain in the output opamp. :wink:

Myself, I never liked the low pass the way it's shown in the clean side, but if it's working for you that's totally cool.

AFFAIK, the bazz fuss is going to act differently if its buffered, as in your scheme. Maybe try putting a small audio transformer at it's input to simulate the load it would see coming directly from a guitar pickup (RE: tim escobedo, jack orman, et al...).

Another recommendation... instead of the replacement for "A" that you've shown, add that opamp at the send jack with a 1M pot in the feedback loop to allow you to send that gain into whatever you have in the loop (or to the bazz fuss).

~ Charlie

[sean k]

This box is basically finished and packed solid so the 100k resistor change is a goody and next time around I'll just have to think of another way of having a decent recovery and a phase reversal.The other possible was to have a transistor after the MPSA13 but at unity gain to get the phase back to as it goes in,maybe a 2N3904 with a small resistor from base to collector.Next time around I'll go for the transformer as well but at the moment theres no way it'll fit in.Thanks chaps.

[Bernardduur]

Nice build btw. Like the changeable input and output caps.

Did you know you can put two caps parallel and put a pot between them so you can dial in every cap value you want? I added that one to my paralooped bazz fuss.