High pitched bell sound whenever key is pressed after MIDI connection

I've been puzzling over this one this afternoon a bit and wondering if anyone has any ideas:

  • Turn the Pro 2 on, press any key. Sounds good like I expect
  • Open up FL Studio.  Press keys, still sounds like I expect.
  • Add a MIDI out instrument to FL studio.  Still sounds like I expect.
  • Set the MIDI out channel to the same channel as the Pro 2.  Suddenly there is a high pitched bell like sound on every key press.
  • Exit FL Studio.  Bell sound is still there.
  • Turn the Pro 2 off and on again.  Bell sound is gone.

All other MIDI devices are off (I checked this first thinking I was hearing something else)

I also noticed that the volume gets a lot louder once FL Studio is talking MIDI out to the Pro 2.
Tested this with multiple patches to confirm it wasn't just that one.

Here's the weird part though:

If I record in some MIDI, then play it back, if I change the patch while it's playing the bell sound goes away, but as soon as I stop playback the bell sound returns on every note.


Forgot to mention: Firmware version 1.4.01

MIDI interface is a Focusrite 18i20.

I'm using a Digital Music Corp MX-8 MIDI patch bay.  My config is set to:
5 -> 1
M -> 2
M -> 3
M -> 4
1 -> 5
M -> 6
M -> 7
M -> 8

Computer (FL Studio) is input/output 1, and Pro 2 is input/output 5
« Last Edit: December 01, 2018, 03:05:29 PM by neonblue »

Re: High pitched bell sound whenever key is pressed after MIDI connection
« Reply #1 on: December 01, 2018, 03:14:58 PM »
Did some more debugging.  This problem seems to be related only to Osc 1.

If I...

  • Initialize the Basic Program
  • Set the level of Osc 1 to 0
  • Increase the level of Osc 2 to more than 0

The problem goes away.

Adjust Osc 1 pitch, shape, and shape mod affects the high pitched sound.

In fact, what I think I'm realizing is this problems is making Osc 1 always play a C10 regardless of what MIDI is sending to it.

Could this be a bug in the latest firmware?


Tested this further by controlling the Pro 2 directly through another MIDI keyboard, through the MX-8, without going through FL Studio.  It works as expected.  So it's definitely something related to the way that FL Studio is sending MIDI to the Pro 2, the Pro 2 will always play Osc 1 as a C10.  Hmm...

More Update:

Whatever the problem is, I figured out that MIDI out from FL Studio plays 7 octaves higher on Osc 1, and at the expected octave on Osc 2- 4.  C0 from FL Studio MIDI will play as a C7 on the Pro 2.  This is why everything sounded like C10, because I was sending notes in the C4 to C6 range, which the Pro 2 was just treating as a C10.

Update 3:

I narrowed it down to a specific MIDI message FL Studio is sending:

Control Change 006: Data Entry (coarse)
Data: 183  6  12

Update 4:

Geeze I need to learn more about the MIDI protocol.  I'm interpreting this as an NPRN command to set parameter 6 to value 12. According to the Pro 2 manual, the NRPN is Osc 1 Wave Right. The parameter being changed (Osc 1 pitch) is NRPN command 0.  If I set global parameter "MIDI Param Receive" to "CC" (it was set to "NPRN" before) from my initial testing the problem goes away.   I still kinda want to understand more of what's going on here because the parameter values don't line up with the manual.
« Last Edit: December 01, 2018, 04:38:22 PM by neonblue »

Re: High pitched bell sound whenever key is pressed after MIDI connection
« Reply #2 on: December 12, 2021, 07:18:20 PM »
Good work debugging. I have the same exact problem with FL studio and the Pro 2. Any midi signal from FL will change the Osc 1 freq to max frequency (C10). However, changing the "MIDI Param Receive" to "CC" does not make the problem go away for me. I have to use a workaround of saving the patch, hitting play or record on FL and then quickly changing out of and back to the patch while FL is playing.

Have you found a solution to this?