Tap Tempo for multiple pedals

LiquidMetal · April 11, 2011, 01:27:31 PM

Greetings!

I want to build a tap tempo pedal to control 3 effects. The basic idea is to build a tap tempo multiplicator. The tap tempo will use an external tap switch (Boss FS-5U) and will control Boss RC-2, Zoom A2 and another pedal (most likely Boss RC-30).

I am planning to use a non-latching 3PDT relay (9v) to control the slaved pedals. I was wondering if this is a good approach. Also, I will appreciate if you can recommend a relay for that application. Finally I was wondering if I need to use some sort of debouncing.

Your input will be greatly appreciated.

Thanks!

Hides-His-Eyes · April 11, 2011, 05:26:12 PM

Most TT pedals are very flexible about what connects them to ground; a simple 2n3904 transistor switch might suffice and save bulky relays.

braiden · May 18, 2011, 05:28:13 AM

I'm interested in this too. I plan on creating a tap tempo for two pedals and was going to use a relay to do it.

What are the consequences of just connecting both of the pedals to a momentary switch without any isolation (assuming they're the same voltage)? Ground loop?

Hides-His-Eyes · May 25, 2011, 09:33:00 AM

It's just bad manners really. Possibility of current flow without a limiting resistor, etc.

braiden · May 30, 2011, 12:21:50 AM

So does anyone know the best way to go about this? Using a relay is the best way I can think of. Any other suggestions?

Hides-His-Eyes · May 30, 2011, 11:00:35 AM

Like I said, a transistor switch. 5V on the base of a 2n3904 with the C and E across the tap tempo connection should work fine.

braiden · May 30, 2011, 07:10:35 PM

Quote from: Hides-His-Eyes on May 30, 2011, 11:00:35 AM
Like I said, a transistor switch. 5V on the base of a 2n3904 with the C and E across the tap tempo connection should work fine.

Could you possibly draw a schematic for it? I am very new to all this.

Hides-His-Eyes · May 31, 2011, 06:49:27 AM

No promises. But this should work.

braiden · May 31, 2011, 08:54:03 AM

Quote from: Hides-His-Eyes on May 31, 2011, 06:49:27 AM
No promises. But this should work.

Thankyou, that's great. Does this work if the voltages for the tap tempo are different between the two pedals? For example, my trem is 5v, and my delay is 3v.

Hides-His-Eyes · May 31, 2011, 09:33:25 AM

In theory; why not. anything over about a volt I think, depending on the C-E forward voltage. They're not isolated per se but they're not pushing eachother.

Just looking at it now I'd put a 1k resistor between the switch and the transistors.

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Tap Tempo for multiple pedals