I have a Moog LP, all the controllers seem to send ok, except CC#51 (Filter Cutoff). Basically it sends random values over MIDI.
I thought at first it might have had dust trapped in the potentiometer, but other CC# functions send as normal via the same pot, only the cutoff (CC#51) is affected.
I did replace a demultiplexer a while back to fix another issue with the pitch bend, could this be related?
I'm not in the studio just now, but as far as I remember the OS firmware is 2.21. I wonder if a re-flash would sort it?
Any help or advice would be much appreciated.
Controller problem on LP
Re: Controller problem on LP
It's possible that everything is normal there; cc51 is the high-resolution "least significant bits" (LSB) of the filter-cutoff parameter...
CC 19 is the MSB, which is the 7-bit normal resolution filter cutoff value.
basically, in between every value step of CC19, you have 127 micro-steps which are represented by CC 51.
If the control was perfect resolution, you'd actually get 127 messages of CC51 in between each CC19 message.
At the resolution we're working with, you tend to see two to four CC51 messages between each CC19 message.
It may look random in someplace like Ableton Live, but if you can view CC19 and CC51 together on one event list, like in Midi Monitor or MidiOX, you should see a pattern.
The pattern is, a CC19 message, a few cc51 messages which should be steadily increasing or decreasing depending on which way you're turning the cutoff knob, then the next CC19 message.
in that version of firmware, I think only the mod wheel and filter cutoff were 14-bit, which could cause the confusion.
In the latest OS, all the CV controls can be 14-bit or you can turn off 14bit MIDI output altogether and send 7bit only.
CC 19 is the MSB, which is the 7-bit normal resolution filter cutoff value.
basically, in between every value step of CC19, you have 127 micro-steps which are represented by CC 51.
If the control was perfect resolution, you'd actually get 127 messages of CC51 in between each CC19 message.
At the resolution we're working with, you tend to see two to four CC51 messages between each CC19 message.
It may look random in someplace like Ableton Live, but if you can view CC19 and CC51 together on one event list, like in Midi Monitor or MidiOX, you should see a pattern.
The pattern is, a CC19 message, a few cc51 messages which should be steadily increasing or decreasing depending on which way you're turning the cutoff knob, then the next CC19 message.
in that version of firmware, I think only the mod wheel and filter cutoff were 14-bit, which could cause the confusion.
In the latest OS, all the CV controls can be 14-bit or you can turn off 14bit MIDI output altogether and send 7bit only.
Re: Controller problem on LP
Thanks Amos.. Where can I download the latest OS?
Re: Controller problem on LP
Go to the Moog website, Products, Little Phatty/Slim Phatty, Software. Make sure you download the LP version, not the SP version. 
Minitaur, CP-251, EHX #1 Echo, EHX Space Drums/Crash Pads, QSC GX-3, Pyramid stereo power amp, Miracle Pianos, Walking Stick ribbon controller, Synthutron.com, 1983 Hammond organ, dot com modular.
Re: Controller problem on LP
Also, be aware that upgrading to a 3.x OS is not reversible back to 2.x OS (without a $30 piece of hardware and opening up your phatty).
Read all the documentation and follow it carefully.
After on a 3.x OS the phatty is much easier to update in the future. It's just the jump from 2 to 3 where you need to be careful.
Read all the documentation and follow it carefully.
After on a 3.x OS the phatty is much easier to update in the future. It's just the jump from 2 to 3 where you need to be careful.