Making a parellel FX loop pedal

[JimBobTTD]

I'm in a 3-piece band, so I'd like some effects to thicken the sound but also keep my clean bass tone. I need to split my signal and send half through my effects and half clean, in other words. I'd like to switch in and out too.

Am I right in thinking that I simply need to:


Input ---->DPDT (middle) ------------------------------------------------------------------------->output
DPDT (top) ---------------->effect loop send [...] effect loop return -------------->output
DPDT (bottom) empty

So, press down on switch and the signal is split between output and FX loop. Press again and the FX loop is bypassed.

I'll draw a schematic and layout diagram in a while, but am I thinking along the right lines? It seems pretty clear-cut to me, but I'm not thinking all that straight today.

Feedback appreciated!

[Mr. Foxen]

Passive splitting is a bit dubious, it messes with impedance and can make stuff sound funny or get quiet. A boss LS2 is what you want, but there are other options, think there is a DHA valve buffered one. I have separate outputs for my pickups and mix them together on the board after pedals (or use separate amps).

[Doddy]

I use a Boss LS2 to switch my effects in and out of my signal path. It does a good
job,and it's got plenty of other usable options.

[JimBobTTD]

Of course...! I knew I wasn't thinking straight.

I'll put a buffer circuit in there:


Switch (A)------------->Buffer------------>FX Loop------>Output
Switch (B)------------->Buffer----------------------------->Output

I'll sort out some kind of schematic and layout and put it up here. I'll also build it and see how it works.

Edit to remove smiley face instead of (B)!!!

Edited March 14, 2010 by JimBobTTD

[JimBobTTD]

Thanks for the suggestions, though, Mr Foxen and Doddy. I like to make my own things, especially something as simple as this.

[Al Heeley]

You could go one step further with a simple blend pot to have the ability to alter the amount of signal sent to the FX loop, so you could switch then between bypass or blend, with wet/dry blend ranging from 0% to 100%. Do a search for a simple blend circuit which adds a transistor, a couple of caps and resistors.

[JimBobTTD]

[quote name='Al Heeley' post='774477' date='Mar 14 2010, 06:44 PM']You could go one step further with a simple blend pot to have the ability to alter the amount of signal sent to the FX loop, so you could switch then between bypass or blend, with wet/dry blend ranging from 0% to 100%. Do a search for a simple blend circuit which adds a transistor, a couple of caps and resistors.[/quote]

A blend function, you say? Challenge accepted!

A: straight to amp
B: FX loop blended in.

[JimBobTTD]

Right...here goes.

Input --> Switch

Stomp on - to "Buff n blend" circuit (Source: [url="http://www.beavisaudio.com/techpages/BlocksFragments/)"]http://www.beavisaudio.com/techpages/BlocksFragments/)[/url]

Stomp off - out


with an extra stomp to switch off the blend (ie 100% to FX loop)
and another stomp at the very start of the box to act as a mute/tuner out.

As far as I can see, this will allow me 4 sounds:

1. Dry signal
2. Blended signal
3. Fully wet signal
4. Muted for tuner

Comments before I go ahead?

[Al Heeley]

I'm a big fan of Beavis stuff. Do it, post pics and let us know how it turns out!