MIDI Expression with Kawai F-10H
Posted: Sat Nov 21, 2020 3:32 pm
Hello Robert,
I recently came across your MIDI Expression pedal interfaces. Great work!
I am considering one to use with a Kawai F-10H continuous sustain pedal. So, I would like to know if your interface and this pedal are compatible and its positions would neatly and usably translate to 0-127 CC MIDI values.
I have done some research by measuring its behavior and taking a look inside. Here is what I know thus far:
- It uses a TRS jack with 'straight polarity' as you call it in your manual;
- So it takes an input voltage with ground on the Sleeve and the + voltage on the Ring. In my test situation I applied approx. 3,25 volts to it;
- With the pedal in the full up position, the output voltage on the S+T as well as on T+R is about half the input voltage on S+R;
- Depressing the pedal gradually to its full down position gradually changes the output voltage: T+R decreases to almost zero, and S+T increases to almost the input voltage.
Now what is different in this pedal from several others (such as the Roland DP-10 in its continuous mode), is that it uses a (presumably optical) tiny proximity sensor and a simple few components (including one tiny transistor) instead of a potentiometer to do this voltage division. The half-voltage on the output in the full up position is also somewhat different, I guess (as opposed to either almost-+ or almost-ground).
So, what do you already know or can you sensibly say about the compatibility of your MIDI Expression interface with the Kawai F-10H?
Out of curiosity, your name 'Robert Jonker' could typically be Dutch, however, I get the idea that you are not residing in The Netherlands. Could you shine some light on this? Also, and this is a word of a little concern: nowhere on your website I have been able to find a company address, actual contact details and so on. It feels a little obscure to me that this forum appears to be the only means of contact. This is less than customary for a business and, if I am not mistaken, would even be illegal to omit in my country (The Netherlands).
Anyhow, thanks in advance for your answers, and keep up the good work,
HZ
I recently came across your MIDI Expression pedal interfaces. Great work!
I am considering one to use with a Kawai F-10H continuous sustain pedal. So, I would like to know if your interface and this pedal are compatible and its positions would neatly and usably translate to 0-127 CC MIDI values.
I have done some research by measuring its behavior and taking a look inside. Here is what I know thus far:
- It uses a TRS jack with 'straight polarity' as you call it in your manual;
- So it takes an input voltage with ground on the Sleeve and the + voltage on the Ring. In my test situation I applied approx. 3,25 volts to it;
- With the pedal in the full up position, the output voltage on the S+T as well as on T+R is about half the input voltage on S+R;
- Depressing the pedal gradually to its full down position gradually changes the output voltage: T+R decreases to almost zero, and S+T increases to almost the input voltage.
Now what is different in this pedal from several others (such as the Roland DP-10 in its continuous mode), is that it uses a (presumably optical) tiny proximity sensor and a simple few components (including one tiny transistor) instead of a potentiometer to do this voltage division. The half-voltage on the output in the full up position is also somewhat different, I guess (as opposed to either almost-+ or almost-ground).
So, what do you already know or can you sensibly say about the compatibility of your MIDI Expression interface with the Kawai F-10H?
Out of curiosity, your name 'Robert Jonker' could typically be Dutch, however, I get the idea that you are not residing in The Netherlands. Could you shine some light on this? Also, and this is a word of a little concern: nowhere on your website I have been able to find a company address, actual contact details and so on. It feels a little obscure to me that this forum appears to be the only means of contact. This is less than customary for a business and, if I am not mistaken, would even be illegal to omit in my country (The Netherlands).
Anyhow, thanks in advance for your answers, and keep up the good work,
HZ