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Brightness Parameter

S_A_P

Brightness Parameter
« on: December 02, 2020, 07:14:22 PM »
Hey folks,

Im building out my Prophet patch manager/editor and noticed CC 74 is labeled "Brightness". What does this control and what knob(s) control this normally? Thanks!

Re: Brightness Parameter
« Reply #1 on: December 03, 2020, 01:25:36 AM »
Hey folks,

Im building out my Prophet patch manager/editor and noticed CC 74 is labeled "Brightness". What does this control and what knob(s) control this normally? Thanks!
usually filter cutoff.

S_A_P

Re: Brightness Parameter
« Reply #2 on: December 03, 2020, 06:54:37 AM »
So there is a filter cutoff(CC73) and a brightness(CC74) parameters that are filter cutoff?

Re: Brightness Parameter
« Reply #3 on: December 03, 2020, 07:05:31 AM »
So there is a filter cutoff(CC73) and a brightness(CC74) parameters that are filter cutoff?
CC74 is a standard MIDI assignment. My guess is that CC73 preserves the 0-120 adjustment range of the original prophet whereas CC74 allows 0-127 adjustment range of the cutoff. I donít have one yet to verify though. Perhaps an owner will be able to jump in.

Re: Brightness Parameter
« Reply #4 on: December 04, 2020, 03:55:12 AM »
Potentially this could be how DSI provides smooth manual filter cutoff sweeps. A typical midi cc only gives you 127 values this isnít enough to provide a smooth adjustment over the full range of the filters cutoff frequencies. By providing two cc youíre effectively / potentially delivering 14k values just like with midi pitch bend data. So one cc will give a rough position the second may enhance this. Certainly the filter cutoff control was always steppy on the Prophet 6 so this maybe an attempt to allow more precise control.
Big synth stuff: https://www.youtube.com/channel/UCJkR38XLkFear5Sf9QypQvA
| Kurzweil Forte | Casio Privia PX 5s | Nord Electro 3 73 | Studiologic Sledge Black| Roland Juno Di | DSI Prophet 6 | Oberheim DPX 1 | EMU Esi 4000 | 2 x Yamaha Tx7 |

Re: Brightness Parameter
« Reply #5 on: December 10, 2020, 03:02:47 AM »
Actually it is recommended in the manual to use NRPN controls. However that does not make any sense, as none of the parameters are actually using higher values than 127. Not even NRPNs.

On the downside of using NRPNs, there is just the fact that midi CC is a single Midi message (3 Bytes) whereas NRPN is in correct manner 4 Midi Messages (12 Bytes). And that is actually increasing the overall bandwidth required to send messages. If you just send a single message, not a problem. If you send a lot of automation to the Synth - you get into constrains on how much you can send per second per parameter. Midi Bandwidth is extremly low compared to modern standards.