DIY True Bypass/Feedback Loop (aka KROK)

[Y tu mama tambien]

CAn some please please post a diagram with it with a DPDT switch please    im a newb to this electronics thing :S

and if someone could also post a schem with 3pdt switches for loop on off and feedback on off... i maybe could get started

[expanoncolin]

CAn some please please post a diagram with it with a DPDT switch please    im a newb to this electronics thing :S

and if someone could also post a schem with 3pdt switches for loop on off and feedback on off... i maybe could get started

Just replace the feedback on/off switch with a DPDT footswitch-one column wired like the feedback on/off switch, one column wired like the LED column shown in my diagram.  If you don't want an LED, j ust get a SPDT stomp.

-Colin

[mrnico]

I built this (the DPDT version) and it works perfectly.

Thank you!

[expanoncolin]

I built this (the DPDT version) and it works perfectly.

Thank you!

 

Pics?

-Colin

[mrnico]

Pics?

-Colin

I wish I had a digital camera. It looks totally awesome as well. As soon as I can tkae a photo of it, I'll post it here.

[aaronzarzutzki]

its cant be too hard to use that combine that ciruit with any pedal
it would be pretty cool for some effects to have a feedback switch on them

i dont like cables

ill start on that box tonight and maybe mod a few of my unloved pedals too

[expanoncolin]

its cant be too hard to use that combine that ciruit with any pedal
it would be pretty cool for some effects to have a feedback switch on them

i dont like cables

ill start on that box tonight and maybe mod a few of my unloved pedals too

It's just a matter of wires and the pot really.

-Colin

[aaronzarzutzki]

master volume....
if i get another 500k pot where should i put it to control output volume?

i used a stomp switch instead of a toggle for the feedback loop
so i need a place where it wont alter the volume of my using the pedals normally or my signal when the loop is bypassed
whenever i find a place the pot can go it looks like its still part of the loop or it affects the volume without feedback

and is the 500k good? or is there a better value to use?
i also do not want options that include active electronics

thanks!

[expanoncolin]

You have three choices for a volume control.

1) After the feedback loop.  It will effect feedback loop volume and general guitar/effect volume.  It will also probably effect the feedback amount.

2) Inside the feedback loop.  This will effect volume AND feedback amount, which is fairly undesireable.

3) An active system.

-Colin

[aaronzarzutzki]

damn... well if i make it active how would i do that?

[smccusker]

I've been working on an active feedback loop system for a few weeks now. Well actually, Colin has done most of the work. Mine uses two of the MXR microamp circuits at GeneralGuitarGadgets, but you'd only need one, post loop I'd imagine.

[expanoncolin]

I've been working on an active feedback loop system for a few weeks now. Well actually, Colin has done most of the work. Mine uses two of the MXR microamp circuits at GeneralGuitarGadgets, but you'd only need one, post loop I'd imagine.

I can't wait til you try it.

All you need to do for the buffer is INSIDE the loop, but BEFORE the 3pdt, put any variety of buffer, MOSFET, op amp, whatever, and THEN put a volume control.

-Colin

[icouldcareless]

Hi guys.
I've just finished trying to make one of these feedback loops, the DPDT version. It's not yet in a box, because I want to make sure it works before buying one.

When I plugged it in, I got a lot of noise, but when i jiggled it around for a while i got my clean signal from my guitar. i played around with the switches, and had to keep jiggling it around to get the sound to come through. I'm guessing this could be a problem with the grounds not wired up correctly?

As in the DPDT version schem, the only ground I am using is from the switch to sleeve of the input jack. Is this right? Should I be wiring any of the sleeves from the other jacks to anywhere? I'm a little confused, because it looks like such a simple circuit, but all I get is buzz.

Thanks, Scott

[expanoncolin]

No-all of the jack's grounds should be connected.  If jiggling the parts makes a difference, some soldering joints are probably shady.

-Colin

[icouldcareless]

Yeah, thanks colin, I figured that out eventually lol. So now it works, but I have another problem. Perhaps a design flaw, perhaps i have wired it wrong.

So i have the toggle switch set to feedback on:

I have the loop on. the feedback pot is up full, resulting in full crazy feedback. When i hit the stomp switch, to bypass it, i have no sound. i turn down the pot, and my volume comes back.
It seems that my pot is acting as a volume in bypass mode, and feedback control when not bypassed but in reverse. so its like this:

(with pot going from 0 to 10 in clockwise direction)

BYPASS: 0 = no sound, 10 = full sound
FEEDBACK: 0 = full feedback, 10 = no feedback

Its a pain to use like this, because you cant use feedback and then bypass it and keep playing

please help. Thanks,
-Scott