If you wire a TRS EXP jack onto a guitar pedal...

[PurpleCatfishBettie]

Is it considered to be like a potentiometer?

[justin3am]

Are you trying to use and Expression pedal to control the Tone or Volume on a guitar or something? If so, there are plenty of examples of passive tone circuits and such, which you could just build into an existing expression pedal.
I guess it depends on how the pot is used. Often pots are used as a variable resistor but they can also be a voltage divider or a current limiter.

Maybe I'm over thinking you question. Most expression pedals are just a pot or a pair of pots.

[annode]

Yeah, you can make an expression pedal from a guitar volume pedal but you`ll need to copy the circuit wiring from the pedal which is designed to work with the gear your intending to control. All expression pedals are not created equal.

[PurpleCatfishBettie]

i was thinking your 'average' expression pedal is basically a pot, then in a pedal circuit, an expression pedal jack basically replaces a pot. i know that 'all kinds of other stuff can be going on', but at a basic level, the exp jack would 'replace' a pot.

i've got next-to-no idea about electronics, and am just mulling over some things 'out loud'.

--Often pots are used as a variable resistor but they can also be a voltage divider or a current limiter.--

that's the sort of thing i didn't know. what's the difference between 'variable resistor' and 'current limiter' by the way?

--All expression pedals are not created equal.--

i figured as much, but don't want to overthink things right now.

for starters, i basically want a 'standard' exp to control a filter freq on the stompbox, and was wondering how that would work at its most basic level.

now, i've got this 'malekko scrutator' and it's set up to where an exp can manipulate the parameters of any combination of the 6 knobs. the users does this by holding the on/off switch down whilst adjusting the knobs the way they are to react, when the exp pedal is to be operational. so right there i figure there's 'potentially' a 'lot more to this' (programmable chips?), but don't want to get into that right now. basically, the idea is to be able to adjust a filter freq with an exp, but not a 'wah' freq...something more like a gnarly lpf instead.

..for a sort of beginner's project, was thinking that a rudimentary fuzz circuit with an exp adjusting a gnarly lpf would be cool. next step would be to have an exp controlling lfo speed, the lfo in turn controlling the filter freq. further, having both options -- exp->freq, or exp-->lfo-->freq -- would be the next thing.

i like the option of having 'leveraged filter sweep speeds' with the exp/lfo/filter, but just having exp/filter would be cool for starters.

ok... yada yada.

[annode]

Sorry, I can't make sense out of what your saying.
A jack can not be a potentiameter.
Both M-Audio EXP-1 and Boss EV-5 expression pedals will work for you.
Both pedals use TRS 1/4” plugs.
Both pedals use a B10K pot for the expression.
Both pedals have a “depth” control which assigns the amount of change the pedal supplies from stop to stop (full throw).
The M-Audio pedal is a universal pedal design. That means it has a polarity switch which allows it to work with most products.
http://www.strymon.net/strymon-tech-cor ... ion-pedal/

[PurpleCatfishBettie]

thanks annode, you basically summed up what i was trying to say.

[annode]

thanks annode, you basically summed up what i was trying to say.

Good deal.
Here`s the other build links;
http://www.strymon.net/strymon-tech-cor ... ion-pedal/
http://www.strymon.net/strymon-tech-cor ... ion-pedal/