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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

Re: Expression Pedals .....
« Reply #9 on: March 10, 2021, 12:24:03 PM »
OK, I put  my voltmeter and resistor decade and measured 3.27V unloaded and 1,63V @ 540 Ω load. In theory, a pedal with a 500 Ω pot would be best, however, you won't find any. A practical solution is to add a resistor with the same resistance as the potentiometer in front of the pot, than the travel is spread out across the whole range.

Best,

Steffan

Re: Expression Pedals .....
« Reply #10 on: March 10, 2021, 02:05:56 PM »
Thanx again Steffan   :)
I will try to make a "experimental" test cable with ability to swap
resistors easily before I do something stupid to my pedal ....    :o

I wish there will be an OS upgrade that fix this "issue" ....   
All I want is the pedal to be as smooth as the Cutoff knob on the front panel,
and not go from "zero to 10" in approximately 4 millimeters ( 0.160 inch )

Weīll se what happens .....

( Havenīt any other experienced this, or is it just me? Nobody use expression pedal
  to adjust cutoff filter when playing solos, like a wha wha pedal for guitar, or like
  a envelope filter on Clavinet ? )    :P

Cheers !
« Last Edit: March 10, 2021, 02:14:28 PM by HockeBocke »
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 #11 on: March 11, 2021, 12:37:13 AM »
Dear HockeBocke,

compared to this, we're all expression pedals beginners:
https://youtu.be/3b1xJYCrKDU?t=94
I learned playing Hammond organ, so I have an almost natural connection to expression pedals.
Forgot to mention above: the input resistance of the Filter pedal jack is 1 MΩ, so you can use hi ohm pots w/o penalties.

Regarding the smoothness: I already expressed my hope, that the filter pedal resolution (time and amplitude-wise) could be increased in this Filter CV post.

Best,

Steffan


Re: Expression Pedals .....
« Reply #12 on: March 13, 2021, 02:42:21 AM »
Now thatīs a serious amount of pedals to master  :o
And the master himself to master them : Vangelis

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 #13 on: April 15, 2021, 08:04:22 AM »
Before this thread ends up on page 3 ....:
I bought me 2 Ernie Ball 6181 pedals and modified them with a Bourns 10k linear pot. That works great! It seems, that a SW update did fix at least the problem, that only a small range up to 1.2 volts has been used. Now it uses the full range. However, one problem is the internal processing of the pedal values. I launched MIDI monitor to trace out the values being sent. If I push the pedal down slowly, I see this:
17:01:20.202   From Prophet 5/10   Control   1   Brightness   0
17:01:25.022   From Prophet 5/10   Control   1   Brightness   3
17:01:25.026   From Prophet 5/10   Control   1   Brightness   4
17:01:25.030   From Prophet 5/10   Control   1   Brightness   6
17:01:25.034   From Prophet 5/10   Control   1   Brightness   7
17:01:25.038   From Prophet 5/10   Control   1   Brightness   9
17:01:25.042   From Prophet 5/10   Control   1   Brightness   11
It misses the values 1 and 2, which leads to an audible step. If I pull it back, 1 and 2 are being sent and the step is much less audible.
Can this be refined in the firmware? I want to do slow filter swells.

Best,

Steffan

Micky

Re: Expression Pedals .....
« Reply #14 on: May 11, 2021, 10:42:08 PM »
Before this thread ends up on page 3 ....:
I bought me 2 Ernie Ball 6181 pedals and modified them with a Bourns 10k linear pot. That works great! It seems, that a SW update did fix at least the problem, that only a small range up to 1.2 volts has been used. Now it uses the full range. However, one problem is the internal processing of the pedal values. I launched MIDI monitor to trace out the values being sent. If I push the pedal down slowly, I see this:
17:01:20.202   From Prophet 5/10   Control   1   Brightness   0
17:01:25.022   From Prophet 5/10   Control   1   Brightness   3
17:01:25.026   From Prophet 5/10   Control   1   Brightness   4
17:01:25.030   From Prophet 5/10   Control   1   Brightness   6
17:01:25.034   From Prophet 5/10   Control   1   Brightness   7
17:01:25.038   From Prophet 5/10   Control   1   Brightness   9
17:01:25.042   From Prophet 5/10   Control   1   Brightness   11
It misses the values 1 and 2, which leads to an audible step. If I pull it back, 1 and 2 are being sent and the step is much less audible.
Can this be refined in the firmware? I want to do slow filter swells.

Best,

Steffan
The same to me...
Iīm really disappointed about the behavior of the pedal at filter cutoff.
I use the Moog EP-3 Pedal, which works really great on all other synths, especially the P 6 and OB6.
At the Prophet 10 itīs noticable steppy and for me the cutoff-pedal is an essential Part to play an
instrument like this !

LPF83

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Re: Expression Pedals .....
« Reply #15 on: May 12, 2021, 04:45:44 AM »
Before this thread ends up on page 3 ....:
I bought me 2 Ernie Ball 6181 pedals and modified them with a Bourns 10k linear pot. That works great! It seems, that a SW update did fix at least the problem, that only a small range up to 1.2 volts has been used. Now it uses the full range. However, one problem is the internal processing of the pedal values. I launched MIDI monitor to trace out the values being sent. If I push the pedal down slowly, I see this:
17:01:20.202   From Prophet 5/10   Control   1   Brightness   0
17:01:25.022   From Prophet 5/10   Control   1   Brightness   3
17:01:25.026   From Prophet 5/10   Control   1   Brightness   4
17:01:25.030   From Prophet 5/10   Control   1   Brightness   6
17:01:25.034   From Prophet 5/10   Control   1   Brightness   7
17:01:25.038   From Prophet 5/10   Control   1   Brightness   9
17:01:25.042   From Prophet 5/10   Control   1   Brightness   11
It misses the values 1 and 2, which leads to an audible step. If I pull it back, 1 and 2 are being sent and the step is much less audible.
Can this be refined in the firmware? I want to do slow filter swells.

Best,

Steffan
The same to me...
Iīm really disappointed about the behavior of the pedal at filter cutoff.
I use the Moog EP-3 Pedal, which works really great on all other synths, especially the P 6 and OB6.
At the Prophet 10 itīs noticable steppy and for me the cutoff-pedal is an essential Part to play an
instrument like this !

The filter pedal is steppy for me as well on the P10 and I also use Moog EP-3s pedals.  Hopefully it can be fixed. 
Prophet 10, Prophet 6, OB-6, Prophet 12m, Prophet Rev2-16, Moog SlimPhatty, Hydrasynth desktop, Korg Minilogue XDm, Roland SPD-30, Roland SPD-SX Special Edition, Roland KT-10, Maschine, Focusrite Scarlett 18i20 3rd Gen + Octopre, Strymon Pedals, Cubase Pro 11.

Micky

Re: Expression Pedals .....
« Reply #16 on: May 13, 2021, 02:17:04 PM »
I hope, they can fix it !
Using the P10-cutoff-knob everything is o.k.
Using the P 10 -Pedal to trigger the cutoff of my OB6 or P6 everything is also o.k.
Because of this i think, it has to be possible to fix that issue !