Category: DAW

Hi Paul. I have a problem with Logic Pro. I get random pitch changes on my synths when I’m playing my MIDI keyboard. I can see the pitch wheel move on the synth. It jumps to a new position and stays there until I reset it with the mouse. I don’t know why this is happening. I’ve tried removing plugins and reinstalling both my Mac operating system and Logic Pro but the problem remains. Can you help?

Charlie

Paul from Audio Support explains how he solved this problem:

I received the above enquiry from Charlie and was able to schedule him into the diary for the same afternoon. At the agreed time, we spoke via WhatsApp and set up a screen-sharing connection via AnyDesk.

Once we were connected, I asked Charlie to show me the problem occurring. We set up a new Logic Pro project with a single instance of Serum. He played in some MIDI notes from his keyboard and almost immediately the pitch wheel on Serum jumped by about fifty percent and stayed in the raised position. An unusual problem.

The first place to investigate issues with MIDI in Logic is the Environment. Specifically, the Clicks and Ports page where incoming MIDI data can be viewed in a Monitor module. We opened the environment and could see that there was pitch bend data being sent into Logic. We changed the monitor routing to confirm the exact source and could see that the pitch data was coming from the MIDI IN port of his M-Audio Keystation 61 MK3.

In the above image we can see information being sent to MIDI Channel 14, CC 0 (pitch wheel) at value 108 or 109. This was the cause of the pitch jumps.

Charlie confirmed he wasn’t touching the pitch wheel and we noticed more data was sent when he wasn’t touching the keyboard at all.

We had now identified the problem as the M-Audio Keyboard and a bit of quick Googling told us that Charlie was not the only person who was suffering from this issue:

https://www.soundonsound.com/forum/viewtopic.php?t=78822&p=772384

It looked like this pitch wheel issue was a hardware problem that was common with M-Audio Keyboards. I’ve encountered a lot of problematic M-Audio equipment in the past, so wasn’t surprised by this.

I explained that Charlie had three options.

1. Replace the faulty keyboard
2. Repair the faulty keyboard
3. Set up a software block to stop the unwanted data being sent to Logic

The budget cost of the Keystation meant that repair wasn’t an option and that replacement was probably the solution long-term.

In order to keep Charlie working for the meantime, I spent the next part of the session setting up an instance of MIDIPipe to block the pitch data. The keyboard would still be sending the MIDI, but it wouldn’t be seen by Logic Pro.

MIDIPipe is an amazingly useful piece of free software and can be downloaded from here:

http://www.subtlesoft.square7.net/MidiPipe.html

The pipe setup was very straightforward:

• MIDI IN – Keystation 61
• Message Filter – Remove all Pitch Wheel information
• A List – To monitor the data post-filter
• MIDI OUT – A virtual MIDI out connection to Logic Pro

In Logic Pro, we set the MIDI input preferences to ignore all the MIDI data being sent directly from the keyboard and avoid doubling the data stream. We tested in Logic and confirmed all pitch wheel information being sent from the M-Audio keyboard was now ignored.

Not the perfect solution, as Charlie could now no longer manually play pitch bends in his MIDI recordings. However, he was able to continue using Logic Pro without having to buy a new keyboard and was happy with the workaround we had put in place.

At the end of the session, Charlie was kind enough to leave me a nice review:

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