REBOTE 2.5... Question regarding endless repeats and a possible kill switch?

[studiostud]

So here's my questions... I have a Rebote 2.5 with an endless repeat switch.  Let say for example I want to add a bunch of guitar riffs with endless repeats so it forms a chaos of noise and then kill it by stomping the pedal off... I'm fine up to this point.  The problem is that when I turn the pedal back on, the chaotic sound is still there.  Is there a way that I can do it so I can turn the pedal off and when I turn it back on, I'm sort of "starting from scratch" with the repeats?

[studiostud]

Posted from old topic...

I'd ground the 1uf cap immediately after the expander, such that ANY delay signal was killed, whether "fresh" or recirculated.

Are we talking about the 1uF cap that follow Pin 14 on the 2399 and leads to the repeats pot?

[flo]

Make sure that when you "... kill it by stomping the pedal off ...", you also cut the signal "repeat" that is fed-back into the delay for instance by pulling the "repeat" pot wiper to ground. This way, the delayed signal is not routed back into the delay input so it is no longer "repeated".

[studiostud]

Sorry for being sort of noobish.  How would I go about grounding the repeat pot?  I have an open lug on my 3PDT.  Would I use that?

[flo]

Hmmm... you could use the voltage that powers the indicator LED, which is switched with the 3PDT footswitch, to control a transistor that is wired as a switch between the repeat pot wiper and ground.

Suppose you put a regular NPN transistor like this:
- Collector to the repeat pot wiper
- Emitter to ground
- Base and a series resistor (1k ohm or so) to the 3PDT lug that switches voltage for the LED.

When the pedal is OFF (bypassed) the voltage on the 3PDT lug should be +9V and so current starts flowing to the Base of the transistor. The transistor is now turned completely ON, thus is a low resistance, and pulls the pot wiper, and thus the repeat signal comming from the pot's wiper, to ground. Make sure that the repeat pot has fixed resistor (100 ohm or something) in series with it so that the circuit that generates the repeat signal does not shortcircuit.
When the pedal is ON (not bypassed) the voltage on the 3PDT lug should be 0V. The transistor is now turned completely OFF, thus is a high resistance, and the wiper recieves the regular repeat signal.

But first, test the idea with a simple wire connected to ground on one side and touch the other side to the repeat pot wiper to see if that has the desired effect of "killing" the repeats! Do this when the repeat pot wiper is not completely turned clockwise but halve way or something so that the repeat generating circuit is short-circuited to ground.

[flo]

That transistor idea would work but, as you already indicated  , we have one unused switch on the 3DPT as part of the DT-switch for controlling the indicator LED. So forget the transistor!

The 3PDT must be wired in such a way that the unused lug of the 3PDT is:
- 0V when the effect is in bypass and the LED indicator is OFF.
- "Floating" when the effect is enabled and the LED indicator is ON.

Much better... now to think of a workable wiring scheme... hmmm .... I'll try to post a concrete wiring diagram later.

And still:
"But first, test the idea with a simple wire connected to ground on one side and touch the other side to the repeat pot wiper to see if that has the desired effect of "killing" the repeats! Do this when the repeat pot wiper is not completely turned clockwise but halve way or something so that the repeat generating circuit is short-circuited to ground."

[flo]

If you wire the DT-switch of your 3PDT that controls the indicator LED like this:
http://pws.cablespeed.com/~danielzink/3pdt-wiring.jpg
The left lug on the bottom row is:
- Connected to ground when the FX is bypassed.
- "Floating" when when the FX is enabled.
Connect this lug to the repeat wiper.

[blanik]

just press both switches at the same time, the bypass (3PDT wired so when in bypass mode the input of the fx is grounded) when you turn the fx on the trail will have disappeared...

and i also recommend lowering the 10k-15k resistor that controls the repeats (the one linked to lug 2 of the repeat pot) to a 7k and put a 5K pot in series with it, that way you can fine tune the endless repeats to have an endless but stable repeat, you can play with the delay knob (changing pitch, etc...) and "keep the thing alive" by feeding in more repeats when the signal is about to die... pretty interesting, it becomes a kind of wave synth... 

another tip, replace the 33K above the TL072 IC on Tonepad's board (the resistor that leads to lug 2 of the level pot) for a 15K, that way you can have a little more delayed signal coming through, unison will be at 3:00 instead than at max level... you never know when that extra little push might come in handy! lol