Triple tap tempo pedal reversed?

[spargo]

I just built a simple tap tempo pedal.  First I did it with one jack (wire one lug of an SPST momentary switch to each lug of a mono jack).  Worked great.  Then I added two more jacks and wired those all to the same points on the switch for three outputs total.  Now the pedal seems to be reversed.  When I'm not touching it, it's like my foot is holding it down and when I press it down it's how it should be untouched.  Backwards.  What gives?

[Processaurus]

If the pedals are different types, especially from different manufacturers, there is no guarantee they use the same electronic system for their tap tempo inputs.  For example, some might be using the tap tempo switch to connect an input to a processor to ground, another might be using it to connect it to VCC.  VCC might be 3.3v in one pedal and 5v in another.  By connecting a bunch together in parallel, it makes a mess.  You're lucky it did anything at all... The only safe solution is either to get to know the system each pedal is using, or make a circuit to make multiple isolated switches, one for each jack, close at the same time, slaved to the physical tap tempo switch.  Something like the CD4066 analog switch would work well, to make a bunch of electronic switches connect the different jacks tip to sleeve at the same time.

If you did some research and figured out what each pedal's tap tempo jack puts out on both the tip and sleeve relative to ground, a simpler solution with a couple diodes and /or resistors might be possible.

[spargo]

But what I should have said is that although I had 3 jacks I only had 1 thing plugged into it.  After wiring the additional two jacks it seemed to have reversed the system.  Only one of the jacks was currently in use.

When it had 1 jack connected I was also able to use it as a sustain pedal for a keyboard.  I wired the other two jacks and now the sustain pedal is always "on" unless I press it down then it stops.  I haven't tried it with multiple tap pedals yet.

[jkokura]

I know that the Cusack guys have gotten it to work. They have a new product out (PBT) with a tap switch that will control three pedals. Perhaps sending them an email will help? Make sure you say that you're trying to do the same thing, and someone said you had already done it, and that you're a DIYer and not another commercial entity trying to steal they're idea... Hopefully they'll point you in the right direction.

Jacob

[Processaurus]

But what I should have said is that although I had 3 jacks I only had 1 thing plugged into it.  After wiring the additional two jacks it seemed to have reversed the system.  Only one of the jacks was currently in use.

When it had 1 jack connected I was also able to use it as a sustain pedal for a keyboard.  I wired the other two jacks and now the sustain pedal is always "on" unless I press it down then it stops.  I haven't tried it with multiple tap pedals yet.

Momentary switches, as opposed to latching switches, only switch when they are held down.  They can either make a connection ( Normally Open, the most common type) or break a connection (Normally Closed) when held down.  Sometimes you get both choices, if it is a SPDT momentary switch.  A sustain pedal is usually a normally closed switch (which breaks the connection between tip and sleeve when you hold it down).  A tap tempo pedal is usually a normally open switch (which connects tip to sleeve when you hold the switch down).

What kind of switch are you using, and how is it wired?

Regardless of the momentary switches polarity, the multiple jack thing on the tap tempo switch probably needs some refinement, so the pedals don't interact with each other.

[Processaurus]

I know that the Cusack guys have gotten it to work. They have a new product out (PBT) with a tap switch that will control three pedals. Perhaps sending them an email will help? Make sure you say that you're trying to do the same thing, and someone said you had already done it, and that you're a DIYer and not another commercial entity trying to steal they're idea... Hopefully they'll point you in the right direction.

Jacob

I need some nukes for my country, maybe your govt could point me in the right direction?  Please help.

[DougH]

What's funny about that is so many of these guys (not Cusak necessarily) act like they are designing nukes, like their pedal stuff is that important and their secrets are a matter of national security... 

[jkokura]

I know that the Cusack guys have gotten it to work. They have a new product out (PBT) with a tap switch that will control three pedals. Perhaps sending them an email will help? Make sure you say that you're trying to do the same thing, and someone said you had already done it, and that you're a DIYer and not another commercial entity trying to steal they're idea... Hopefully they'll point you in the right direction.

Jacob

I need some nukes for my country, maybe your govt could point me in the right direction?  Please help.

I don't know if Canada has nukes, but I'll ask next time I'm in parliament.

Jacob

[Processaurus]

Sweet!  Bout time they spent some of that money they've been using for health care on doomsday devices.  I looked at the Cusack site, were you talking about their giant bradshaw type switcher with the 3 RCA jacks for the tap tempo outputs?  I wonder if those work for any pedal or just their proprietary thing they stick on all of their tap tempo effects. 

Something universal might be done using 3 transistors as voltage controlled switches, hooked to one tap tempo switch.