Momentary switch to stomp switch help needed

[scott1568]

Hey all.

I am trying to set up my tremolo with a momentary "On" switch.

I built a Tremulus Lune- great tweekability and all.

I have on my parts bin a couple of momentary switches. I want to enclose the switch in its own mini box with a 2 - 3 foot cable run to the Tremulus.

How do I  wire the switch to the Main stomp switch  to engage the effect (or circuit board if that's how you would like to think about it.)

The goal is to  switch in the effect at various points in the song with a momentary . I release my foot and the pedal effect is disengaged.

Please point me in the right direction - so appreciated !

[R.G.]

Actually, that's a problem.

If you have a normal stomp switch for your main bypass switch, it's going to be really hard to get it to let go when a remote switch makes or opens. The problem isn't getting a momentary switch. Those exist, and you could make the pedal always momentary, but making it be alternate action AND momentary is what's hard.

There are ways to do this, of course, but they are fairly involved, and mostly require making the actual bypass switch be a relay, CMOS analog switch, or buffered+JFET setup so that it can be controlled by the logical action of a switch, not just the real, hard metal contacts of a switch.

A small relay is conceptually the simplest way. That will cost you about $3.00 for the switch if you're in the USA, plus additional parts to hook it up properly, a board of some kind to put it on, all the normal "Oh, yeah, you need wires, resistors, caps, solder..." stuff.

By the way, Mark Hammer, a long time contributor to this forum is a big fan of momentary punch-in switching too.

[slacker]

Are you bothered about it being true bypass?  It's much easier to do if you're happy to have at least the momentary option not be true bypass.

[Mark Hammer]

By the way, Mark Hammer, a long time contributor to this forum is a big fan of momentary punch-in switching too.

Commander Keen is correct about that.

Looking at this schematic: http://fuzzcentral.ssguitar.com/tremulus/tremulusschematic.gif (which may not be exactly the one you're working with), I can think of some ways to select between latching and momentary tremolo.  They can be used with TB or without.



Like the Anderton/EPFM tremolo ( http://www.generalguitargadgets.com/pdf/ggg_catrem_sc_orig.pdf ), the optoisolator varies the input resistance of an LDR in an inverting op-amp.  As the LED glows brighter, the LDR resistance drops, and the op-amp stage-gain goes up.  Craig's design adjusts the max gain via a pot in parallel with the LDR, where the Tremulous Lune does so via a variable feedback resistance for that stage.

Whatever the method of gain adjustment used, one thing remains true: if the LED don't light up, then the LDR don't change.  And that's what we can use to our advantage.

Let's say we stick a 100k resistor in series with the 1k going to ground from the LED half of the optoisolator.  By restricting the current flow through the LED, it will be so dim that it may as well be off (feel free to raise the resistance above 100k).  A SPDT toggle can select between either directly bridging that added resistor, or indirectly bridging it through a SPST momentary footswitch.  Step on the footswitch, and the LFO will now produce changes I the LED's illumination.  Lift your foot and the LED goes dark.

In theory, this ought to work, whether the pedal is used with a 3PDT stomp bypass, or simply unbypassed.  Note that you could leave it unbypassed, and use the momentary to engage it. 

[mth5044]

What if a DPDT momentary was used to connect signal to the send and return like this? (also could be a beautiful butterfly)



The DPDT is shown in the unpressed position. When the effect is bypassed by the main bypass switch, pushing the momentary switch will punch the input into the send of the circuit and the return to the output.

EDIT: Oh wait, I see OP wants to do this remotely. Nevermind.

[Mark Hammer]

Whether remote or in-the-box, one of the things about momentary SPDT, DPDT, and similar, switches is that they have a definite click and tend not to be as smooth as plain vanilla SPST momentaries, unless you're paying big bucks, and have a source.  If a switch has to switch from this contact to that one, it necessitates a different sort of mechanism, or at least different implementation of it, that ends up degrading the fluidity that the OP seeks.

I tried to implement two different momentary functions on a pedal, one with SPST and the other with SPDT.  World of difference in terms of feel and fluidity of use.

[scott1568]

Thank you all very much!

The truth of the matter is that I had submitted this question ( a couple years ago) to the commonsound.org forum, got an answer, but never followed through.    Now that forum is down.

The pedal is not true bypass from what I can tell. I am going to check your posts again carefully this weekend and see what I can do. It's been a long long week and I need to be patient with it.

Thanks all and I will report back.

[scott1568]

NO! You might be on to something! The switch will be wired ( I think I said that). A smaller box will house the momentary switch and  I will run wires from momentary box TO the main effect. I will shrinkwrap the wire group and do some sort of strain relief at both ends.

I want to place the pedal away from my pedalboard.

When I play live, I find my base tone and leave it alone (for the most part) .....except for some boost during soloing if needed.


I want to place that momentary switch box where it is convenient for me to stomp without hunting for it. . I am going to paint it yellow so my foot can find it better!

Honestly, I am grateful to be in a band, but stage lights can really mess with your vision up there.

What if a DPDT momentary was used to connect signal to the send and return like this? (also could be a beautiful butterfly)



The DPDT is shown in the unpressed position. When the effect is bypassed by the main bypass switch, pushing the momentary switch will punch the input into the send of the circuit and the return to the output.

EDIT: Oh wait, I see OP wants to do this remotely. Nevermind.