Super-duper-looper, would this work? Help needed!!!

[vanessa]

I want a good looper for a bass. I've seen the Splitter-blend from ROG and the Paralooper. I like both but would like the best of both worlds and I came up this (sorry for who ever's schematic this is, I can't read Japanese but will take this down as soon as I work the bugs out of mine.). I want the low pass filter in there (do you even need the high pass if the low is implemented?). Would this work?

 


See below

[tommy.genes]

So your intent is to also have a send/return jack pair in the EQ leg of the paralooper? I mean, it certainly seems like that is your intent, but it doesn't hurt to make sure.

Anyway, assuming that I understand what you want, it looks OK but needs one correction. You would need a coupling capacitor before the send jack on the EQ leg (J6). Just as you added C11 to duplicate what C6 is doing, you also need to do the same for C4. Alternately, you could move C4 "back" towards pin 1 of U1 so that it feeds into both R5 and R6 (it is only feeding into R5 as shown). I see that you already added the bias "back in" before going into U1b.

And now a suggestion, not so much a correction: having built a paralooper for bass myself, I've found the stock LPF shown on that schem to be rather underwhelming in terms of its usefulness. A single-pole, passive LPF just doesn't provide much radical tone shaping by itself. I'd suggest investigating a Big Muff tone control or "tilt control" - both are single-knob controls that actually boost low frequencies as opposed to just cutting the highs.

Good luck, and be sure to post a build report when done. 

-- T. G. --

[vanessa]

Something like this?

See below

[vanessa]

What's the purpose of R5? It looked like a high pass filter with C4...

[tommy.genes]

Yep, that's what I meant about C4.

I think R5 is a pull-down resistor for C4 (allows excess charge on C4 to bleed to ground if J3 should be plugged into an open circuit). It should still serve that function even with C4 in its new location. Anyone who knows differently is certainly welcome correct me however.

-- T. G. --

[vanessa]

Just a bump for good measure.

[vanessa]

Here is the latest version with a phase switch. Would 220k work for R16, R17, R18 (like the Splitter Blend)?

See below

[tommy.genes]

I can't say I've done a detailed analysis, but it looks close enough to go to breadboard. As for R16, 17 & 18, I can't see any reason they have to be any different than they are at runoffgroove.com. That circuit segment is pretty well isolated between C6 and C7.

One more problem I've found with my paralooper - it pops when I first switch it on. Placing a 1M pull-down resistor to ground on the left side of C1 should fix that.

-- T. G. --

[vanessa]

Finished?

[tommy.genes]

I don't see where you added the 1M resistor to the left of C1. Perhaps you linked to an old version of the image file?

(That is assuming, of course, that you wanted to take my advice to include it. Forgive my presumption if not.)

-- T. G. --

[vanessa]

It's there, 1M just to the left of C1. 

[tommy.genes]

Sorry. The old version of the image was in my cache!   

Refreshing the page revealed it...

And yes, that is what I meant.

-- T. G. --