The Official Sequential/Oberheim Forum
SEQUENTIAL/DSI => Prophet-5/Prophet-10 => Topic started by: HockeBocke on January 23, 2021, 05:50:58 AM
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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 !
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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.
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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
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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 !
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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
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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 !
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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
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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.
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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
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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
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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 !
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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
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Now thatīs a serious amount of pedals to master :o
And the master himself to master them : Vangelis
Cheers !
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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
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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 !
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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.
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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 !
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Did this issue ever get resolved????
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Did this issue ever get resolved????
It got much better after OS update 2.0.1 :)
Cheers !
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Did this issue ever get resolved????
It got much better after OS update 2.0.1 :)
Cheers !
Better, but not really as good as it should be...