Hey everyone,
I received my Slim Phatty a few days ago. It’s my first Moog (my first analog synth even), and I am thoroughly in love!
However, I’ve noticed that when recording the MIDI for fast filter cutoff tweaks on high pitched notes, the cutoff isn’t modulated as smoothly when the MIDI is played back to the SP. It results in a raspy sound. Listen to this mp3 for a before/after recording:
http://www.poorgramming.com/SlimPhatty_MIDI_Alias.mp3
The first tone is the original recording, with manual filter cutoff tweaking. The second tone is the MIDI from the first recording, played back to the SP.
It seems that the SP doesn’t “smooth out” fast, jagged MIDI input message values, even for 14-bit control messages (such as filter cutoff), or it doesn’t send them out fast enough to begin with. Other options are, the MIDI protocol doesn’t allow for faster control messages, or somehow my DAW setup is eating MIDI data.
As far as outside contributing factors, I’ve been able to count out the following by process of elimination:
- Logic Pro has “MIDI Data Reduction” turned off. The data it receives is pretty much the same as the data it sends out. I’ve been able to verify this by looking at input/output using the MIDI Monitor app.
- Using Logic and the MIDI Monitor app, I’ve made sure there were no duplicate/conflicting MIDI events sent to the SP that could interfere with each other. The SP was only receiving MIDI on one of its ports, on one channel.
- The MIDI data isn’t being truncated by slow USB rates or hubs; the same effect happens when going from the SP to my Motu UltraLite (Firewire) over MIDI DIN. And again, MIDI is a very low-bandwidth protocol… it shouldn’t be a factor. (Right?
) - The SP is sending and receiving full 14-bit MIDI data for the cutoff (CC19/MSB and CC51/LSB). If I remove all the data from CC51, the raspy sound gets worse (which makes sense). When just sending CC19 events from a midi controller plugged straight into the SP, the same raspiness occurs (which also makes sense.)
- The project used to record the above was set at 120 BPM. The MIDI tick rate should be high enough for fast, smooth tweaks… or am I wrong?
In any case, if there’s anyone who can reproduce this and/or tell me what a possible solution would be, that’d be greatly appreciated.
Thanks much!
