KVR Audio

igoramos · Post by **igoramos** » Sat Sep 23, 2017 4:45 pm

I bought a Yamaha FC7 after many recommendations and have not had a good experience with it. The values transmitted are "jittery" and jump values and increase way to fast over the travel of the pedal. Makes is very hard to control with my foot. I've tried for hours to adjust it and even took it apart and cleaned the potentiometer with no luck.

Please recommend a good (but hopefully not super expensive) reliable pedal.

Thank you!

IA

surferman · Post by **surferman** » Sat Sep 23, 2017 5:13 pm

I bought and ART x-15 ultrafoot midi pedal some years ago and it works great in Amplitube with the wah pedals and volume pedals.

igoramos · Post by **igoramos** » Sat Sep 23, 2017 5:39 pm

surferman wrote:I bought and ART x-15 ultrafoot midi pedal some years ago and it works great in Amplitube with the wah pedals and volume pedals.

thanks! Looks like this came out in the 80s and has been discontinued with no newer similar controller. I do wonder about the Behringer FCB1010 or either of the Keith McMillen step controllers (though they are super expensive...)

deastman · Post by **deastman** » Sat Sep 23, 2017 5:45 pm

I just have a cheap M-Audio one, so no firsthand experience with better ones. But I know that both the Roland and Moog pedals are generally considered to be pretty good quality.

igoramos · Post by **igoramos** » Sat Sep 23, 2017 5:48 pm

deastman wrote:I just have a cheap M-Audio one, so no firsthand experience with better ones. But I know that both the Roland and Moog pedals are generally considered to be pretty good quality.

Thanks. Was just looking at this one:
https://www.amazon.com/gp/product/B00GG ... CV58&psc=1

So what do you think of the M-Audio? Is it smooth and with comfortable and controllable foot travel?

deastman · Post by **deastman** » Sat Sep 23, 2017 5:58 pm

My standards are pretty low!

It performs its function well enough for occasional casual use, which is all I wanted. It feels like cheap plastic, which it is. Again, I don't have any basis for comparison, but my gut instinct tells me that the Roland and especially the Moog are much higher quality. I also don't know how the Roland compares to the Boss version.

deastman · Post by **deastman** » Sat Sep 23, 2017 6:02 pm

Wow, that's a great price on the Moog! I'm tempted to get one myself. If there is one thing Moog is known for, it is great workmanship. I doubt you'd be disappointed with that one.

igoramos · Post by **igoramos** » Sat Sep 23, 2017 6:08 pm

deastman wrote:Wow, that's a great price on the Moog! I'm tempted to get one myself. If there is one thing Moog is known for, it is great workmanship. I doubt you'd be disappointed with that one.

haha. I was thinking along the same lines. thanks...

JCJR · Post by **JCJR** » Sat Sep 23, 2017 8:24 pm

igoramos wrote:I bought a Yamaha FC7 after many recommendations and have not had a good experience with it. The values transmitted are "jittery" and jump values and increase way to fast over the travel of the pedal. Makes is very hard to control with my foot. I've tried for hours to adjust it and even took it apart and cleaned the potentiometer with no luck.

Please recommend a good (but hopefully not super expensive) reliable pedal.

Thank you!

IA

Hi IA. What keyboard are you connecting to?

The symptom you describe of "all the control range is compressed into only a small amount of the total pedal travel" is a common symptom if you connect a "yamaha wired" pedal to a keyboard expecting roland wiring, and it can also happen if you connect a roland-wired pedal to a keyboard expecting a yamaha wired pedal.

For instance I have an ancient ensoniq plastic pedal which looks near identical to some of the generic modern pedals still for sale. Maybe there is a factory somewhere in the world thats been using the same plastic molds for decades now.

Anyway the old thang still works fine, but ensoniq used "roland wiring" and connected to my yamaha kx88 it goes from full off to full on in the first quarter inch of travel, then stays full volume all the rest of the pedal movement.

By opening the pedal's plug and swapping the wires between ring and tip, leaving the ground sleeve wire undisturbed, now the old ensoniq pedal works great with the kx88 but doesn't track worth a damn on my roland keyboards after the wiring change. Before the simple wiring change it worked great on rolands and sucked on the kx88.

Most all keyboards are wired to expect it either one way or the other. Swapping the ring and tip wires at the plug will probably fix your problem (for the specific keyboard giving you trouble).

There could be other things wrong. Changed wiring is not a guaranteed fix. But your reported symptoms are "what you can expect to happen" from a "mis-wired" pedal.

I mean, there are even properly-wired (for the keyboard) pedals with bad scratchy potentiometers or potentiometers with the wrong resistance taper or where the little plastic gears have not been adjusted properly connecting the pedal travel to the potentiometer rotation.

resynthesis · Post by **resynthesis** » Sat Sep 23, 2017 8:54 pm

Make sure the pot value is correct for your use too - it varies a lot! There's a pretty old and incomplete list here:

http://www.harmonycentral.com/forum/for ... 9/1678997-

I've had good luck with Boss and Mission pedals over the years. I also use a Behringer FCV at home and it's doing fine at the moment.

igoramos · Post by **igoramos** » Sat Sep 23, 2017 9:26 pm

JCJR wrote:
igoramos wrote:I bought a Yamaha FC7 after many recommendations and have not had a good experience with it. The values transmitted are "jittery" and jump values and increase way to fast over the travel of the pedal. Makes is very hard to control with my foot. I've tried for hours to adjust it and even took it apart and cleaned the potentiometer with no luck.

Please recommend a good (but hopefully not super expensive) reliable pedal.

Thank you!

IA
Hi IA. What keyboard are you connecting to?

The symptom you describe of "all the control range is compressed into only a small amount of the total pedal travel" is a common symptom if you connect a "yamaha wired" pedal to a keyboard expecting roland wiring, and it can also happen if you connect a roland-wired pedal to a keyboard expecting a yamaha wired pedal.

For instance I have an ancient ensoniq plastic pedal which looks near identical to some of the generic modern pedals still for sale. Maybe there is a factory somewhere in the world thats been using the same plastic molds for decades now.

Anyway the old thang still works fine, but ensoniq used "roland wiring" and connected to my yamaha kx88 it goes from full off to full on in the first quarter inch of travel, then stays full volume all the rest of the pedal movement.

By opening the pedal's plug and swapping the wires between ring and tip, leaving the ground sleeve wire undisturbed, now the old ensoniq pedal works great with the kx88 but doesn't track worth a damn on my roland keyboards after the wiring change. Before the simple wiring change it worked great on rolands and sucked on the kx88.

Most all keyboards are wired to expect it either one way or the other. Swapping the ring and tip wires at the plug will probably fix your problem (for the specific keyboard giving you trouble).

There could be other things wrong. Changed wiring is not a guaranteed fix. But your reported symptoms are "what you can expect to happen" from a "mis-wired" pedal.

I mean, there are even properly-wired (for the keyboard) pedals with bad scratchy potentiometers or potentiometers with the wrong resistance taper or where the little plastic gears have not been adjusted properly connecting the pedal travel to the potentiometer rotation.

Thanks a lot for letting me know. I'm using Komplete Kontrol S61. I'll check on this polarity thing to see if that is the culprit!

igoramos · Post by **igoramos** » Sat Sep 23, 2017 9:27 pm

resynthesis wrote:Make sure the pot value is correct for your use too - it varies a lot! There's a pretty old and incomplete list here:

http://www.harmonycentral.com/forum/for ... 9/1678997-

I've had good luck with Boss and Mission pedals over the years. I also use a Behringer FCV at home and it's doing fine at the moment.

Thanks! didn't know about this at all. much appreciated.

stimresp · Post by **stimresp** » Sat Sep 23, 2017 10:02 pm

Maybe a bit pricey, but this one is well-built and has served me well (after I wasted money on crappy plastic pedals)

http://www.morleypedals.com/m2-mini-expression-pedal/

JCJR · Post by **JCJR** » Sat Sep 23, 2017 11:37 pm

resynthesis wrote:Make sure the pot value is correct for your use too - it varies a lot! There's a pretty old and incomplete list here:

http://www.harmonycentral.com/forum/for ... 9/1678997-

I've had good luck with Boss and Mission pedals over the years. I also use a Behringer FCV at home and it's doing fine at the moment.

There are so many keyboard and guitar circuits maybe it is unavoidable that some designs would be sensitive to the resistance of the pot.

I would ignorantly guess that "generally" the pedals with log pots may be designed to do double-duty function as either passive guitar volume pedal or alternately expression pedal function. Though there is no law which would prevent a company from using a dual "stacked pot" in a double duty pedal, with a 50 kOhm Log pot for passive guitar volume and linear 10 kOhm for synth expression pedal function. For instance that would be one obvious way to make a passive stereo volume pedal, with a dual 50 kOhm stacked pot, one for each channel.

I am woefully ignorant of modern guitar processors, but here is another possible explaination for the use of log (or anti-log) pot in a voltage pedal-- The majority of synthesizers are designed to appropriately respond to linear control changes. For instance on analog synths, 1 volt per octave. So a 0 to 10 volt range would evenly divide up into 10 octaves. Or maybe at 1 volt per 6 dB (or whatever), 0 to 10 volts would give a smooth 60 dB control range. Each tenth of pedal motion changing volume by 6 dB.

But some synths (historically the minority) were designed to track exponential voltage. If 0.0625 volts to 0.125 volts controls the first octave, then 0.125 to 0.250 volts controls the second octave, 0.250 to 0.500 volts controls the third octave, etc. Or in volume, if 0 to 0.125 adds the first 6 dB gain, then 0.125 to 0.250 adds the second 6 dB of gain, etc.

The reason some synths were designed thataway is because exponential voltage control required fewer parts and were generally more temperature stable. The analog circuits which converted linear to exponential and vice-versa tended to need precision parts and calibration, and tended to drift with temperature changes unless the parts and design was good enough to avoid temperature drift. For instance old Yamaha CS50, CS60, CS80 used exponential voltage control and were rock-solid tuning stability, at least when new. I read nowadays old ones can have tuning issues, but a new CS was infinitely more tuning stable than a new Oberheim or a new Prophet 5 of the same era (linear control voltage machines with linear-to-exponential converters lots of places inside).

Apologies for the doddering old guy drifting so drastically off topic. I'm just saying that since it takes fewer parts for instance to make an exponential-controlled VCA, then there may be some guitar processors that want exponential pedals (log pots) in order to use exponential-controlled circuitry inside the processors. Just a wild-ass unfounded guess.

For plugging an expression pedal into a keyboard, maybe some keyboards are sensitive to the absolute resistance. Am purt certain most all keyboards would want linear pots.

The expression pedal pot acts as a voltage divider-- The "bottom leg" of the pot is wired to the plug sleeve, grounded at 0 volts. Then we either connect the top of the pot to the tip and the wiper to the ring, or do it the other way around.

A sane designer would design the circuit so that it can't burn up anything inside the keyboard if you plug in a shorted pedal. You want to supply some level of DC to the "top leg" of the pot, and then measure the voltage of the middle "wiper leg" of the pot. Maybe apply 5 volts, or 10 volts, whatever makes sense. Put maybe a 100 ohm or 1000 ohm resistor in series with the DC voltage (inside the keyboard before the jack connection). That way even with a shorted pedal, or all three ring-tip-and-sleeve all shorted together, it still won't burn up anything inside the keyboard. Or you could use fancier current-limiting tricks but resistors probably cost less than a penny apiece.

On the input from the pot wiper, you would probably add some protection diodes to protect the CV input terminal from getting fried if negative voltage or excessively-high positive voltage is applied. Though probably not protected safe enough to connect the pedal input to the house AC mains without damage.

The wiper input will most likely be buffered by an active gain stage or voltage follower. I'd guess a reasonable input impedance perhaps 100 kOhm or whatever. Low enough to avoid too much risk of interference noise messing up the pedal sensing, but high enough to work with a wide variety of pedal resistances.

I haven't looked inside many keyboards lately, but for instance if the DC voltage is supplied thru maybe a 100 Ohm resistor and the pedal wiper is buffered by 50 kOhm or 100 kOhm, then a 10 kOhm or 5 kOhm linear pedal would probably work "near indistinguishable" to a 25 kOhm linear pedal.

Which is even more wild-ass guessing and unfounded generalization.

Aloysius · Post by **Aloysius** » Sat Sep 23, 2017 11:52 pm

Looking for smooth decent quality Expression Pedal