DIY True Bypass/Feedback Loop (aka KROK)

[Peanutismint]

Ah of course - that makes much more sense! Thanks again :-)

It's kinda fun trying to re-learn all these things! I can only remember my GCSE stuff as far back as NAND gates and 555 astable timer circuits! :-D

**UPDATE**

Totally working now.  Thanks so much!!

[Vierphoria]

I need help, ASAP. Please.

I built this feedback loop:
http://remmelt.com/electro/media/switch_schem_400.png
and it works like a charm (after som tweaking; I, of course made a mistake in wiring...

However, I've no fricking idea as to HOW i should connect the LED and DC-jack.
I think I understand that they should go somewhere on the empty line of lugs, but... yeah.

Please help me.

[expanoncolin]

I need help, ASAP. Please.

I built this feedback loop:
http://remmelt.com/electro/media/switch_schem_400.png
and it works like a charm (after som tweaking; I, of course made a mistake in wiring...

However, I've no fricking idea as to HOW i should connect the LED and DC-jack.
I think I understand that they should go somewhere on the empty line of lugs, but... yeah.

Please help me.

See this image in the bottom right corner:



The only change you need to make is that the battery - (black wire) should go directly to the second lug down (middle) on the rightmost column, not the bottom left lug as shown, and there should be no connection between the bottom left lug and the second lug down on the rightmost column.  You could also rewire it to match this schem if that sounds confusing to you.

-Colin

[ragz]

Built a feedback looper attached to a pedal board. I used a hybrid schematic based on Colin's. It is housed in a repurposed electrical box from a local resale yard. 
 

[green1jeet]

Hi, This is my first attempt at DIYing, so I thought I'd start out simple..
I built this on a bread board with a 470K potentiometer and mono plugs (grounded all together)..
It works fine bypassed and with the loop engaged but when I enable feed back it has no effect, decreasing the resistance produces a small feedback till the dial reaches the end, there it just goes crazy: phasers/flangers just beep and fuzz/overdrive just produces static..
BTW, I'm using the Zoom G3 on the loop, is it a problem of the multiFX, does this work better with single pedals?
Appreciate the help..

[expanoncolin]

It depends on the pedal.  Multi-FX will often not work in a particularly nice way.  Try some analog overdrive/distortion/fuzz pedals.

-Colin

[SNAKE9298]

Hey there, total newbie here who used the guide to build this as his first pedal, had to use a 470k instead of a 500k for the pot but other than that followed the instructions to the dot but unfortunately I'm getting no sound whatsoever even with the effect off there just nothing

[expanoncolin]

You've wired the sleeves as tips and tips as sleeves on your 1/4" jacks.  Look at the second image posted for a diagram.

-Colin

[SNAKE9298]

Thanks for the help Colin, we now have sound and it's working as an A/B switch but unfortunately theres no effect so I think maybe I've gone wrong someplace so may start again.

[cactusfriend]

Found this board today - just wanted to make a quick note to people who are having the issue where it works as a true bypass looper, but the feedback knob does nothing or something unexpected - a passive feedback looper like this is not going to work on digital pedals, and it's not going to work on pedals that invert the audio signal via a buffer.  Dunno if anyone's mentioned this before, if so, I'm sorry!

[expanoncolin]

Welcome cactusfriend.  I don't think that's true about digital pedals though - plenty of digital pedals I have have worked fine.  They just have to have enough gain to allow a positive feedback loop to happen.  The results can vary, but not all analog pedals will work either.

-Colin

[cactusfriend]

Cool; maybe it's just the way that I made mine, or the fact that I've had very few digital pedals to work with, hehe

I might try adding a buffer with selectable signal inverting or something in the future to help with those pesky pedals that don't work!

[abeamt]

Is it possible to add a dry signal to this thing? Just a simple pot that would allow me to dial in a direct, unaffected signal while the loop is engaged.

[expanoncolin]

Is it possible to add a dry signal to this thing? Just a simple pot that would allow me to dial in a direct, unaffected signal while the loop is engaged.

If you buffer the feedback loop output and buffer your dry input, you could wire them to an active or passive mixer which would allow for blending of the dry signal.

-Colin

[abeamt]

Is it possible to add a dry signal to this thing? Just a simple pot that would allow me to dial in a direct, unaffected signal while the loop is engaged.

If you buffer the feedback loop output and buffer your dry input, you could wire them to an active or passive mixer which would allow for blending of the dry signal.

-Colin

Well, my original idea was to just put a wire from the input to the output, running through a 500k pot. Just a dry signal that I can dial in and out, rather than a blend knob. When I did that, though, it just caused the pedal to glitch.