Author Topic: Global Tap switch  (Read 2935 times)

G. Hoffman

Global Tap switch
« on: January 18, 2010, 06:18:14 AM »
I'm starting to work on a new pedal board, and I want to have a single global tap tempo switch for my MV-53 based tap trem, my Boss DD-20, and possibly a couple others (I will likely be getting at least one or two more tap delays, and a tap Vanishing Point comes to mind) that I will be adding as time goes by. 

So, what is the best way to go about this?  I'm assuming I can't just connect the tap switch I've been using with my DD-20 to a mult (a group of parallel wired jacks) and connect it to all the switches, right?  So, should I use something like a 4066, with all the control inputs hooked up to the tap switch?  Or something else? 

I was thinking it might be nice to have something like a tap clock for the whole board, and use something like Molten Voltages MV-52, or a greatly simplified version of Electric Druid's TapLFO chip set to a square wave.  I've not yet learned any PIC programing myself, so I'm not ready to come up with a new PIC project myself (yet - I am working on it!)

So, any thoughts?


Gabriel

free electron

Re: Global Tap switch
« Reply #1 on: January 18, 2010, 07:37:41 AM »
To avoid generating more ground loops between pedals i'd use an optical separation. A bunch of cheap optocouplers (like CNY17 or 4N25) will provide separated open collector outputs.
I have an unfinished project based on this idea, i think i'll put up a new DIY project on my site soon :)
The pcb i designed was for 3 separated outputs and fits into 1590A enclosure.

JKowalski

Re: Global Tap switch
« Reply #2 on: January 18, 2010, 01:28:06 PM »
or a greatly simplified version of Electric Druid's TapLFO chip set to a square wave. 

I made one of these for the 8-pin PIC12F683.

You can find it here

It gives you:

A tap input
A clock output
A tap LED (lights on first tap, turns off on second tap. Two taps set the tempo. If it is tapped once and left alone - it only waits for tap two for four seconds or so - the phase will reset so that you can tap it once and bring it back into sync. )
A manual tempo control CV (overrides tap input until next tap)
A tempo multiplier control CV (x0.5, x1, x1.5, x2, x3, x4)



I don't know if there is a standard for tap inputs... There should be....

Some may need negative going pulses and some may need positive going pulses, soo.... A single switch may not work... You could maybe use a DPDT to do positive going pulse and negative going pulse at the same time...