EDIT: At the end the problem was the ES100 all along. Kawai said that the first units has this problems and they fix it. For me, they repair the unit for free and now it works great.
Now, my original post:
After buying the Kawai ES100 digital piano, I was (and still am) very happy about it. I have nothing bad to say about the ES100, except very minor things I will post on a full review.
But the pedal that came with it (F-10H) although looks very well made, with a lot of metal parts, heavy, stable, silent, apparently working well... but after some little time after using it was clear something was wrong about that pedal. Was a long story to figure out what was the problem, but now I know. Problem is latency (delay). When you press fully, the signal send to the digital piano have around 0.115 to 0.172 seconds of delay, and even 1 second in some circumstances I will explain later.
People that play an instrument like the piano know that 0.115 of a second of input delay is quite a lot. The pedal shows (with my ES100 digital piano) 6 to 7 steps in total. Each step has a delay that adds on, from full-press to release.
This is the delay between values:
Delay with F-10H pedal:MIDI message from 10 to 30 = 0.012 seconds of delay
MIDI message from 30 to 55 = 0.014 seconds of delay
MIDI message from 55 to 84 = 0.021 seconds of delay
MIDI message from 84 to 116 = 0.032 seconds of delay
MIDI message from 116 to 127 = 0.093 seconds of delay
Total delay with F-10H pedal from 0 to 127:
0.172 seconds
Notes that delay is bigger the more the pedal is press.
Delay with a switch pedal:MIDI message from 10 to 30 = 0.002 seconds of delay
MIDI message from 30 to 55 = 0.001 seconds of delay
MIDI message from 55 to 84 = 0.002 seconds of delay
MIDI message from 84 to 116 = 0.002 seconds of delay
MIDI message from 116 to 127 = 0.005 seconds of delay
Total delay with switch pedal from 0 to 127:
0.012 seconds
Note: For those who don't know about MIDI, values are 0, 1, 2, 3...until reach 127 (that is full)
Using a switch pedal proves the problem is the kawai F-10H pedal itself since is obvious the digital piano electronics can process pedal signal very fast (0.012 seconds maximum from 0 to full).
What problems in real life this cause?Issue "late pedal": Is the most obvious problem I had that actually make me start investigating about all of this. Is quite important problem because when pressing a key, and releasing the key at the same time when pressing pedal, sound should sustain normally all the way. But because of the latency on the pedal, the key is partially damped (called "late pedalling"). As most of you should know, pedal usage is all about timing. This slight delay can really ruin a song quite often. Even pressing pedal a little earlier than releasing key, late pedalling issue is present dampening a little the sound. You are force to leave the key press for longer time, and this is not always possible, and is not realistic.
Issue "full pedal delay": Sometimes when fully pressing the pedal, the MIDI monitor (digital piano is connected to a computer) shows an important delay on sending the FULL (127) state. The delay is sometimes even over a second. It freeze on 116 value and after a while it sends 127 (full).
Here is a short video showing both issues in action:
https://www.mediafire.com/?dp41hw2w3mm2w9aIssue "pedal damper noise effect": The digital piano Kawai ES100 supports this effect. The pedal noise is louder the faster you move the pedal, like on an acoustic piano. But since the F-10H pedal sends data with such latency between steps, the digital piano always thinks the pedal is moving slowly so the damper noise is always too soft, no-matter how fast/hard the pedal is press. This issue is not super important, and that is why I mentioned last. But still, was something I notes even before I knew about all of this pedal-latency thing.
Obviously the delay also happens when releasing the pedal, but I didn't notes that when playing so I don't mention that as an "real life issue", although technically it is.
After I discover this, I remove the cover on the F-10H pedal, and looks like it use some kind of optic sensor. Not sure what cause the latency in there. My bet is the sensor itself, but the problem could be some other component.
Other kind of pedals like the Yamaha FC3 use potentiometers to send half-pedal position. Problem with potentiometers is that they wear out after some use. But at least potentiometers send data practically in real time (no delay). The initiative of kawai to use optic sensor is very good to prevent wearing (the pedal in theory could last dozens of years), but sadly they fail on making them latency-free. Everything about input on a instrument most have as little delay as possible. 0.001 of a second is very good; 0.01 of a second is acceptable; 0.1 of a second is terrible.
Maybe I have a defected unit?
What about other pedals like the Kawai F-350 triple pedal unit?
I don't know since I didn't have a chance to test other pedals, and I don't have an answer from Kawai yet. I will post any news about this here in the future, if there is anything to report.
If any of you are interested on the schemat of the pedal, my friend dewster write it down here (thanks dewster):
For now, I will see how solve this problem for real. I want half pedal feature so will test with potentiometer pedals and see if any of them is compatible. Until then, switch pedal should be enough.
If any of you have the F-10H pedal, please do the test to see how much delay it has. Could be that I am just unlucky and got a defective unit. The way to test is connect the digital piano to the computer and install pianoteq (trial version works fine). In pianoteq there is a setup section where shows MIDI messages is receiving. That is what I use on the video I record. You simply write how much time it takes from having the pedal release to fully press.