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Expression Pedals .....

Expression Pedals .....
« on: January 23, 2021, 05:50:58 AM »
Hello.

Tried my two different expression pedals with my P-10 today.
Plugged into "Filter".  Noticed that one of them were a little bit
smoother than the other and opened up the filter with "normal"
movement of my foot.   :)
The other pedal opened up very fast with small movement of foot.   >:(

The smoother pedal has a 50kOhm pot , and the fast pedal has a 10kOhm pot .

Has anyone had the same experience ?  Thereīs nothing specific in the Manual
about this, only that the connectors "accept a standard expression pedal that has
a variable resistor on a TRS (tip-ring-sleeve) 1⁄4 inch phone plug."

Would a pedal with a 100kOhm pot be even smoother ( and easier to handle by foot  ;)    )  ???

Cheers !
       
1976 MiniKORG700s // 1978 Prophet-5 rev.2 // 1981 KORG CX-3 // 1984 DX7 // 2020 Prophet-10 rev.4 // MoPho Box // 2 Creamware MiniMax // Creamware Pro-12 // 2 EMU-Proteus 2000 // EMU-Vintage Keys  // Casio VZ-10M // Roland VK-8M // Fatar SL 880 //

Re: Expression Pedals .....
« Reply #1 on: January 23, 2021, 01:33:34 PM »
I have some different expressions pedals (Moog, an ancient Yamaha and a Yamaha FC7, Behringer, Polivoks) and they all behave different. Normally I use the Behringer expression pedal that suits me best.

Re: Expression Pedals .....
« Reply #2 on: February 13, 2021, 08:17:31 AM »
You can use the expression pedal inout as a Filter VC input. So, any pedal with a the pot wiper wired to the tip will do the trick. I use a the Exp CV from my Moog Matriarch. It's a bit steppy and filtered, so fast LFO or sequencer voltages are smoothed.
I wonder, if this can be changed in a firmware update. 10 bit resolution and a faster response would be great!

Best,

Steffan

Re: Expression Pedals .....
« Reply #3 on: February 17, 2021, 05:39:24 AM »
You can use the expression pedal inout as a Filter VC input. So, any pedal with a the pot wiper wired to the tip will do the trick. I use a the Exp CV from my Moog Matriarch. It's a bit steppy and filtered, so fast LFO or sequencer voltages are smoothed.
I wonder, if this can be changed in a firmware update. 10 bit resolution and a faster response would be great!

Best,

Steffan



Maybe Iīm "stoopid" or maybe itīs because I donīt speak english every day, but I canīt
understand what youīre trying to say here .....     :-\

Cheers !
1976 MiniKORG700s // 1978 Prophet-5 rev.2 // 1981 KORG CX-3 // 1984 DX7 // 2020 Prophet-10 rev.4 // MoPho Box // 2 Creamware MiniMax // Creamware Pro-12 // 2 EMU-Proteus 2000 // EMU-Vintage Keys  // Casio VZ-10M // Roland VK-8M // Fatar SL 880 //

Re: Expression Pedals .....
« Reply #4 on: February 22, 2021, 03:29:30 AM »
Ok, try to re-wording things:
There are two types of expression pedals, which differ by the way they're wired:
#1: (Roland)
Tip: output or control voltage, taken from the wiper of the potentiometer
Ring: input or reference voltage
Sleeve: ground.
#2: (Yamaha)
Tip: input or reference voltage
Ring: output or control voltage, taken from the wiper of the potentiometer
Sleeve: ground.
Here's a link describing it more detailed:https://www.making-sound.co.uk/projects/expression-pedal-meter.html.
The Prophet likes wiring #1. This has the advantage, that you can feed a control voltage from an Eurorack system with a simple Tip/Sleeve cable. That works well and allows you to use an external LFO or sequencer.
So, for the prophet, you need a Roland pedal or you need to modify the wiring. I prefer the Yamaha FC-7, it's easy to to modify and rock solid. But it needs to be re-wired or you need an adapter cable.

Best,

Steffan

Re: Expression Pedals .....
« Reply #5 on: February 22, 2021, 11:24:11 AM »
OK, thanx for clarifying   :)
I got the #1 type of pedal, but another brand (not Roland), so I guess I just
have to get used to its behavior or wait for an OS update that maybe fixes the
"issue" with this "too sensitive filter action" with expression pedals .
If there is an "issue" at all ?   :-\  Maybe itīs just me ...... :o

Cheers !
1976 MiniKORG700s // 1978 Prophet-5 rev.2 // 1981 KORG CX-3 // 1984 DX7 // 2020 Prophet-10 rev.4 // MoPho Box // 2 Creamware MiniMax // Creamware Pro-12 // 2 EMU-Proteus 2000 // EMU-Vintage Keys  // Casio VZ-10M // Roland VK-8M // Fatar SL 880 //

Re: Expression Pedals .....
« Reply #6 on: March 02, 2021, 10:01:19 AM »
Dear HockeBocke,

I tried to demystify the filter pedal jack a bit with a voltmeter:
- on the ring, I see ~3.3 volts
- on the tip, a voltage between 0 and 1.2 is expected.
This explains this sensivity issue: a Pedal like the FC-7 uses the whole range of the potentiometer (I'm sure it's the same with Ernie Ball, Roland etc.). So, after a third of pedal travel you reach the end. To improve that, you need a voltage divider at the wiper or an additional resistor on top of the potentiometer.

Best,

Steffan


Re: Expression Pedals .....
« Reply #7 on: March 02, 2021, 01:11:15 PM »
Thanx Steffan.
So if I understand it right, a pot with higher Ohm rate would do the same
as adding a resistor, as per my question in my first post, to make a smoother
filter travel / response ?  Am I right ?   :o

// H.
1976 MiniKORG700s // 1978 Prophet-5 rev.2 // 1981 KORG CX-3 // 1984 DX7 // 2020 Prophet-10 rev.4 // MoPho Box // 2 Creamware MiniMax // Creamware Pro-12 // 2 EMU-Proteus 2000 // EMU-Vintage Keys  // Casio VZ-10M // Roland VK-8M // Fatar SL 880 //

Re: Expression Pedals .....
« Reply #8 on: March 03, 2021, 11:15:19 AM »
Depends on the resistor, that is already in place to protect the 3.3 volts. The pot should have about the same value, then it would be perfect. I need to dig out the resistor decade to take a measurement ...

Best,

Steffan