Anyone ever had any luck with sending CV to the rubberneck? I’d love to do this with my A4 too but am scared of damaging something… I tried finding out what the voltages were that the FS3x sends but couldn’t find anything anywhere.
I emailed Digitech about it and here is their answer:
but this unit doesn’t even have an expression pedal input. So, I would say that it cannot be done. If you are referring to the FS3X input, then that is just for a 3 button controller via tip-ring-sleeve (such as the FS3X) for controlling certain functions on the rubberneck.
Yeah which is really too bad because its a fantastic pedal.
Though I did not think to ask them what the voltages were. They were under the impression using cv to control expression can’t be done. 
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that doesn’t seem to make much sense to me
a regular expression pedal divides a provided voltage across its variable resistor and returns a control voltage representing the position, it shouldn’t matter how that voltage (if within range) is generated - so it’s certainly possible with some gear to supply that return voltage, say on the tip, and if you used a TS cable the pedal sent voltage would ground, so it has no idea if an expression pedal is there or not probably - it just works with the provided voltage - there should be a tonne of examples of doing this around the web if you need examples
now it’s a different thing altogether with how they implement the signal back from the fs3x, it may well not be an expression pedal supporting port - you can find schematics for the fs3x online, it uses a nifty way to get three push to make pedals on it - in terms of the fs3x I’d wager you had a chance to set up a cv scenario that mimics the some of the expected returns that the pedal monitors for the various states
tbf, the fs3x pedal is actually quite cheap by all standards, I made a cheap clone so I could add other switched functions within the enclosure for a different digitech box, but making one is an option to access the functionality, if not via the preferred method in op - at least not without some more digging into what the rubberneck expects to see - there’d definitely be a way to use a4 outputs to trigger those switches within a bespoke (possibly active) fs3x clone, so that sequenced voltages could effect a push to close process by other means than stomping - iirc I was looking for an ic which did something along these lines in a search here, so it isn’t super tricky to voltage control a momentary switch
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Thanks for the reply, my knowledge of electronics is pretty basic but I think I understand what you’re saying… a clone of the FS3x seems like a pretty easy first project and adding the voltage controlled push to close aspect of the circuit seems like it should be pretty straight forward? I’d currently be clueless with how to get started but I’m sure by the time I’m ready to get working on this I could figure it out one way or another… Would be very interested to hear if anyone gets this working one way or another!
A regular expression input can usually be controlled with cv.
EHX and other companies say in the manual what voltage range, how much V you can max run into it.
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if you know what the functions are that the fs3x triggers and can establish from the fs3x circuit diagram which way the circuit is flowing via the TRS you could probably set a limit on a voltage sent via the a4 with no worries (your risk of course) and see if you get any functional response
you can set a value Lin to max out at 1v and use locks/encoders modulators etc to set the range coming from that cv lane - and see if you get any luck
I’m not an expert, very far from it, but I take calculated guesses to get solutions to work and I’ve managed a few projects just fine to do what I needed - if you make a fs3x then you could intercept your wiring with a multimeter to get more info
the a4 control of a fs3x would be a plan b solution, I’m sure a plan a can cut the fs3x out, but that’s a complete guess - there is probably info if you broaden a google search into the fs3x (or similar products) workings for pedals that use that scheme with the added diodes
at its source the functionality is likely very simple, there’s voltage coming into the fs3x, it is monitoring some aspect of what is returned depending on switches used
proceed with ideas from non-experts only when you are sure you won’t damage anything through your own checking
e.g. this reddit discussion hints at a similar end game by getting the zoia to see differing voltages as a response from the fs3x presses - it should get the ideas flowing for other chats
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Yeah I was honestly surprised that they claimed a exp pedal input couldn’t read cv. I kind of gave up on the idea of getting help from there after that.
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I’ll probably give it a try with my A4, so long as I’m careful I can’t see how it’d be possible to do damage but then again, I’m no way near an expert on this haha…
I’m guessing I’d need a trs to dual tr cable to have access to all that the fs3x can do?
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I’m really interested in seeing where this goes. I’d love to be able to cv control the Rubberneck.
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TRS cable or TRS if you want to use both cv outs from the A4, TRS to TS if you want to use only one cv out from A4. With TS only tap tempo and regeneration can be controlled.
fwiw - I just looked at my digitech and it sent 3.2v across the tip and across the ring, so it’s monitoring via those inputs to the fs3x … given the wiring within it and not truly knowing how they are monitoring the state changes for all combinations I cannot really say for sure - but whilst there may be no easy ‘plan a’ as per above without some thought, there’s at least a viable plan b and it gets you a working fs3x pedal in tandem too - to my thinking it should be possible to power the ic from the a4 cv input so that it triggers the momentary switch which you wire in parallel with the mechanical switch, so either or can open the circuit - there may be no direct way to talk from the a4 so unless you find info to the contrary don’t go wild with any experiments there, even the one I mentioned above
in the zoia set to an expression cport e.g. it sends 5v out the ring and receives the divided return via the tip - so you mimic that by sending direct to the tip via cv between 0-5, I just checked it works with either an expression pedal or cv source (as exp return) and it was fine, so the option should be supported on other similar expression ports with different gear
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my very cheapskate fs3x+ fwiw (squeezed in a new input socket to cater for the extra 3 switches)
you can make these for nothing, but I haven’t yet tried out the ic I found and linked back here …
Thanks again for all the replies, happy to have received so much info on it! it does seem like it should work without issue and I just need to tread carefully when trying to find out what voltage the rubberneck expects.
Excited to try this out though as I think there’ll be some very exciting possibilities with this 
I should just buy a multimeter really and take a reading from the T/R/S of the rubberneck, so I might end up doing this as it’s something I want to get anyway… Any recommendations?
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I’m not going to try that with the jamman - it’s sending +ve voltages out the two poles of the jack, I’m not sure the answer it’s expecting is voltage back in those, maybe it’s looking at current flow internally, I dunno - but I’d hate to see you bork the pedal as it’s clearly not like the simpler scenario where it talks to an expression pedal yhbw 
Hi! I’ve been having the same idea! Did you succeed with it?
I just bought a Beatstep just to try it, waiting for it now.
Greetings from Argentina!
The Rubberneck does not have an expression pedal jack. That´s why DOD mentioned, that it does not take CV (instead of an expression pedal).
But the functions, that are switched by the fs3x pedal can be switched by CV (if you use a mosfet or jfet as a switch). But you can only switch them on and off. It´s not possible to change values with CV.
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I recently picked up an ALM SBG Pedal interface which includes a 3v/5v exp output. With a 3.5mm to 1/4" mono between the 3v and the DOD, the Regen would turn on with a 0 or below voltage source. Notbadnotbad.
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Are you sure, that it´s save to use a TS plug instead a TRS? It constantly shortens the ring …
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Uhhhhh I am not…what? 
Edit: 
Bad news is, no, it’s not technically safe. Good news is that most TS cables (according to the article) are safe. Either way ordering some floating ring cables asap. Thanks for the heads up!
Ok, that’s something! I think I could send 3v from my Beatstep Pro pretty accurately. Will try that later!
The question now is how to get it to control the rubbernecking function…
If you happen to understand this more than me (this is extremely probable), I’m following this clues:
This guy controls his SuperEgo+ with a Drum Gate from the Beatstep (12V).*
When you see the manual of that pedal, the “External control jack” chapter recommends to use a DigiTech® FS3X, and then it reads:
“USING EXTERNAL CLOCK TRIGGER WITH A 1⁄4” TS CABLE
You can also use a clock signal to trigger the Superego+ BYPASS function.
Connect the clock signal to the TIP of the EXT Jack. Each negative-going clock
signal present at the TIP connection is equivalent to pressing the BYPASS
footswitch. The nominal amplitude for the clock signal is 0V to 5V. The
Superego+ is triggered by the falling edge of the clock signal.”
My guess is that, using a weirdly wired cable, you can access the combination of tip, ring & sleeve that goes to the Rubbernecking function?
I hope I made myself clear, and I repeat: I do not know nothing concerning CV.
Cheers to everyone in here!
*Source: kind of contradictory Arturia (arturia. com/faq/beatsteppro/beatstep-pro-general-questions):
- Gate Outputs: 12V.
If your destination device requires 5V, it will work and won’t damage it.
But in long term, we advise to use attenuators to avoid any risk of premature wear.