Loopbox with feedback.

[Sam]

I currently use a homebrew loop-box to, when disengaged, place my buffered modulation pedals completely outside the signal path. The box also has a tuner-out with a mute switch.

Since I like to make really messed up noice music I've been thinking...

I'd like to have a box with a swithable true bypass loop (just as mine) but with an additional switch engaging a feedback oscillation within the loop (like the Effector13 TBD) and a gain knob for the oscillation. So, this pedal would act as a normal loop-box and a feedback loop oscillator.

I haven't bee able to fint the suiting schematics for this...

[maximee]

I remember Ansil had an easily understandable design....basically you just have to connect the FX send and FX return with a pot, say 500k and a switch...that's it...
I can dig up Ansil's layout when I get home if you like...

[snorky]

Dig around the forum for "Total Sonic Annihilation" and you'll find some good information.  I really want to make one of those one of these days...

- Mark

[Sam]

I remember Ansil had an easily understandable design....basically you just have to connect the FX send and FX return with a pot, say 500k and a switch...that's it...
I can dig up Ansil's layout when I get home if you like...

Great! I'd appreciate that!

I might want to give the "noiceloop" a little distortion by placing a small "lo-fi" distotion circuit in the loop... Any ideas about which circuit to use?

[Marcos - Munky]

E-mail me for the schematic of it.

[Sam]

E-mail me for the schematic of it.

Eh...

Actually I'd don't have any chematics. It's just a few thoughts on what I want to build...

[LivingDeadPunk]

Try that, it's a true bypass feedback loop.

http://experimentalistsanonymous.com/board/viewtopic.php?t=134

[Sam]

Try that, it's a true bypass feedback loop.

http://experimentalistsanonymous.com/board/viewtopic.php?t=134

That looks great!

My thoughs are to add some form of simple clipping circuit to the feedback loop - just to get that extra texture and maybe be able to limit the loops volume... Any thoughts? I'm a newbie at pedal building (just one build).

Is there any danger of damaging other pedals with a feedback loop like this?

Oh, and by the way, it seems he's (see link above) using all the connections on the switch. How do you get a LED into that design? Millenium bypass?

[LivingDeadPunk]

On this pedal you've got a 500k pot to limit the volume.

I don't think there are any danger for other pedals, I'm not that sure about your speakers or your ears,  :? .

This box is a passive one, If you want to add a LED you'll have to add a power supply, and change the box to a BB size one since it will be a bit overcrowded in a B size one.
I don't know how to do that with this design but I reckon you'll be better off trying to make this pedal first then try to mod it.
If you really want a LED and clipping stage, the best way to go would be an active loopbox with the same wiring used for the feedback loop on http://experimentalistsanonymous.com/board/viewtopic.php?t=134


Maybe you'll be interested in this:
http://pg.photos.yahoo.com/ph/neptun_krusen/detail?.dir=8ef7&.dnm=d46d.jpg&.src=ph

[Sam]

Thanks for the help!

Allright, here's my design (based on Death by Audio TSA and Arons True bypass Loop-box.

First switch is for fx-loop on/off. Second for feedback on/off (when fx-loop is active).

Schematic: http://photobucket.com/albums/y8/JSam/?action=view&current=fblooper.bmp

Do you think it will work?

Next stage will probably be to add a small lo-fi clipping circuit (or tone circuit) to the feedback loop...

[LivingDeadPunk]

I think it should work.

If you're looking for an easy to build lofi effect try the lofomofo at General guitar gadget, it is very lofi, actually I've got a lofomofo and I was thinking about adding it to a loop/feedbakc box, I 'dont know what the result will be though, I might be horrendous. :twisted:

[runmikeyrun]

i'll second the lofomofo.  Easy build.  Socket the caps to custom tailor the high/low pass frequencies to your taste.

[Sam]

Great!

I've been thinking.Wouldn't it be cool to have a three-way switch to either have...

1) LofoMofo off (bypassed).
2) LofoMofo on, after feedback loop (to give the noice lo-fi "radio"-sound).
3) LofoMofo on, in feeback loop (to really mess things up   ).

What kind of switch would this require and how should i connect it? What do you think?

[LivingDeadPunk]

It would indeed be cool and nasty.

In order to have the lofomofo on/off after feedback loop, you just need to add it to your pedal and wire the two effects as explained at GGG, http://www.generalguitargadgets.com/pdf/two_in_one_wiring.pdf

If you want to have it in the loop I think you should wire it between the return jack (input) and the 3pdt switch (output).

There must be a way to switch between these 2 modes (in/after loop), a spdt switch or a rotary switch but it's 2.30 AM and I can't think clearly.

I'll think about it when I wake up, I'll think about doing a tone stack as well, I'd like a low/high EQ like the Ibanez LF7 has.

[Sam]

LivingDeadPunk wrote: "There must be a way to switch between these 2 modes (in/after loop), a spdt switch or a rotary switch but it's 2.30 AM and I can't think clearly.

I'll think about it when I wake up, I'll think about doing a tone stack as well, I'd like a low/high EQ like the Ibanez LF7 has."

Cool! I'll give it some thought.