Slim Phatty 14-bit MIDI CC messages
2011-01-31 by Alex
Hi all,
In a few days I will receive my Moog Slim Phatty buy reading the user's manual I have some doubts about 3 parameters that use 14-bit MIDI CC messages.
These parameters are:
· Cutoff CC# 19 (MSB) CC# 51 (LSB)
· Mod Wheel CC# 01 (MSB) CC# 33 (LSB)
· Arppegiator Clock Rate CC# 04 (coarse) CC# 36 (fine)
· Mod Wheel CC# 01 (MSB) CC# 33 (LSB)
· Arppegiator Clock Rate CC# 04 (coarse) CC# 36 (fine)
The questions are:
1. The manual says the range for these parameters is 0-127. Why don't it say 0-16384?
2. If I want to control one of these parameters with my BCR2000 in only one encoder, can I achieve it assigning a NRPN in Absolute (14 bits) mode, is that simple? e.g. NRPN# 19 for Cutoff?
Thank you so much in advance.
MORE INFO TAKEN FROM THE MANUAL
1. The Slim Phatty sends and receives 7-bit MIDI CC messages for all parameters except for the Modulation Wheel and Filter Cutoff, which receive high-resolution, 14-bit MIDI CC messages. This allows for finer control and smoother changes for these parameters. For these two parameters, the MSB indicates the ‘regular’ CC number, and the LSB indicates the high-resolution ‘fine’ control value. If you are only sending 7-bit MIDI CC messages to the Slim Phatty, use the MSB channel number by itself for these two parameters.
2. The Arpeggiator Clock Rate is set by two MIDI CC messages that correspond to coarse and fine clock rates. The coarse rate is set by CC#04 in increments of 3 BPM over a range of 21-320 BPM, and the fine rate is set by CC#36 in increments of 0.1 BPM. To set the clock rate, first set the coarse rate by dividing the target BPM by three; the integer result (the whole number) will be the CC#04 value. Then set the fine clock rate by subtracting the coarse BPM value from the target value and multiplying the result by 10. This will be the CC#36 value.
For example, to set the Arpeggiator Clock Rate to 121.7 BPM:
Determine the MIDI CC coarse value by dividing the target BPM by 3:
121.7/3 = 40.566
The CC#04 value is ‘40’ (=120 BPM)
Determine the MIDI CC fine value by subtracting the coarse BPM value from the target value:
121.7 - 120 = 1.7
Then multiply the result by 10:
1.7 * 10 = 17
The CC#36 value is ‘17’
For CC#04 = 40 and CC#36 = 17, the Slim Phatty’s display will show ‘121.7 BPM’.