Re: multi-function momentary switch

[brooklynhero]

Greetings!

I am thinking about delay pedals that have tap tempo momentary switches that also allow for runaway feedback when depressed for a long period of time. Like the EHX Deluxe memory boy and the roland RE20.

How does that work? is there a relay that switches based on the amount of time the momentary switch is depressed?

Ultimately I'm wondering if it's possible to create a dual function momentary switch that bypasses the effect when quickly tapped (as per usual) and when depressed for a longer period of time (and with the effect engaged) - lifts the feedback pot for self oscillation.

hopefully a small daughter board can work for this function.

delay is a normal PT2399 unit like the Zero point.

[jkokura]

Not a relay, but a microcomputer. These are programmable units, and have been programmed to do different things based on the input given.

For example, a common microcomputer we're using these days is the taptation. We're using it to do tap tempo delays using the PT2399 chip. It's been programmed to take a tempo, tapped into a momentary switch, and turn it into a signal that a digital pot can read. In addition, the computer reads the state of a couple switches, giving input on the division rate of the tapped tempo, and then modifying the tempo based on their states. Also, the microcomputer acts as a driver for at least two LEDs which give feedback on both the tempo and the division state.

So, to move back to what you're asking, you can program a chip to both receive the tap tempo from a momentary switch AND do something different when held. Often with these switches a calibration mode is entered, but not on the taptation. Sometimes, like the examples you've given, the switch provides runaway feedback. In that case, we'd have to program a part of the microcontroller to also control the feedback pot. Not impossible, just another facet to program.

This is much easier on fully digital delays like the two you've mentioned. Since we control the PT2399's feedback using Analog means, and not digital ones, it gets to be a bit more complicated. Doesn't look the same.

However, you can do the same thing via analog means. I think it makes more sense to use two switches, one for tap tempo, and one for runaway feedback. Then you'd have to include bypass as well, but it's less complicated than trying to program a microcontroller to do all that stuff.

Jacob