In Your Face

I'm working on a 30dB boost pedal.  Working name: IYF!

Mix 'em Together

Most of my recent efforts have been centered around creating a multiple channel parallel mixer for a guitar pedalboard.  There are a few pedals out there that mix a single parallel signal with the dry signal from your guitar.  Out of those pedals there was only one that I knew of that was really geared towards wet FX with the need for spill over.

My original intention was to create a 3 channel parallel wet mixer.  The idea was to run a dotted eight note delay in channel one, an eight note delay in channel two, and a reverb in channel three.  All of the pedals would need to be capable of producing a 100% wet effect signal.

Here's what my first prototype looked like.  As you can see, I drilled first, and asked questions later... much, much, later.

This prototype had some major design issues.  The biggest one being that the entire circuit was tied to a voltage reference instead of ground.  The pedal wouldn't be able to daisy chain to a non isolated power supply.  There was also a lot of clicking and popping problems when turning on and off the bypass and the sends.  This wouldn't normally be such a problem except that when a delay was in the mix as designed, the click would get repeated 7 or 8 times.

I also realized that there weren't to many enclosures readily available that could comfortably fit four footswitches and eight 1/4" jacks.  

Here's the current prototype.  I settle on having two parallel channels with a dry level control, 2 send controls, and a master boost.  The 2 sends can be individually controlled by the first and second footswitch and the returns are hardwired on (when the pedal is on).  This creates a nice spillover of delays and reverbs.  When the pedal is bypassed, everything is taken out of the signal path, so there's no bleed from the returns.  The master boost can be set from unity gain to about 10dB. 

The circuit is now correctly referenced to ground so it can be daisy chained with no problems.  I used an RC in the LED circuits which softened up the clicking quite a bit.  I also changed all the regular electrolytics to low leakage electrolytics.  This solved the send switching clicks but the master bypass was still causing clicking that would get repeated by any delays, echos, or reverbs in the mix.

I switched from 3pdt true bypass wiring, to true bypass relay switching, and there are no more switching issues.

Sample PCB's and parts have been ordered, and if they turn out good, I'll probably build up about 10 of these.  I'll post more pics soon, and some gut shots of my nasty looking perfboard prototypes.  I'll do a more extensive demo video of this soon.  There are so many great sounds you can get out of this thing, like an over driven dry signal with a totally clean pitch shifted delay.  Here's the original video.