Building a tap-tempo box

[jtguitar]

Hi all, I'm wondering if there is any info to be found on building a tap-tempo box? I've searched the forums and Google for info, but I'm struggling to find anything definitive.

I'd like to build a tap tempo box using a momentary switch, but I'd like to be able to connect it to multiple pedals at once.  I have an Eventide TimeFactor & PitchFactor and I'm hoping to get a Cusack Tap-A-Whirl.  I'd like to be able to tap in tempo to them all at the same time.  Do I need to do anything special, or just wire up the switch to the output jack (as I've seen in a few posts)?

[earthtonesaudio]

If all the pedals read their tap signal in exactly the same way, you can simply hook up a single switch with multiple jacks and parallel them all.

But chances are they aren't all the same, so you have to put in some extra bits to make each output do what its intended effect wants.

For example if the Eventides want to see a normally open connection but the Cusack wants a normally closed, then you can use a SPDT momentary, with the normally closed side going to the Cusack and the normally open going to the Eventide(s).  The center terminal would be common to both so it would have to be at ground.


Bottom line: you have to check out what each pedal wants.  If they all have identical requirements, congratulations!  The wiring will be simple.  But if any one pedal has a different set of requirements, then it needs special treatment.

[JKowalski]

What you might want to do is use active digital logic to get it done. Basically, use one switch to toggle a bank of inverters. Use dip switches to set the output polarity of each tap output, that way you can easily adapt it to any setup you have... The pedals will probably accept a +5V/0V signal in place of being pulled down to ground but if you want to stay as true to the original conditions as possible (and allow for non-5v triggers) you can use the signal to switch a transistor on the output...