External keyboard triggering unseen piano sound!

Hey everyone –
Never had this before. Cubase 12 user on a 2019 Imac. I use a Moog Subsequent 37 as my main MIDI keyboard.

Today, while programming some drums, I noticed I also heard a piano sound being triggered. But I can’t tell from where!

All the other synths are off in the room. The sound is unaffected by turning down my the mixer all my gear runs through. No piano VST is open. If I remove all VSTs, it still happens. That said, the Sub37’s volume does turn it down (though no other Sub37 knobs do anything), I imagine thru midi cc.
I eventually opened a brand new project – just to eradicate variables – and same thing… my sub37 is somehow triggering an unknown piano somewhere within Cubase!

Any ideas?

I write as I’m thinking…

  • How is your Moog Sub 37 connected to your DAW ? MIDI only, or is there some audio connection involved ? What kind of track(s) are you using for it in Cubase ?
  • Does this happen, no matter the preset used on the Moog Sub 37 ?
  • Is there a local on/off toggle on it, and if so, how is it set ?

The Sub37 is connected via USB, which it uses to send and receive MIDI. It’s audio is sent over 1/4inch to the mixer, which is down. No external audio is hitting Cubase.

And yes, if I change the preset on the Sub37, same thing. It’s definitely the Sub37 doing the triggering. But WHAT it’s triggering remains a mystery.

OK, but you haven’t answered about an eventual local on/off setting…

Beside this, are you sure that Cubase is the only audio source ? IOW, any other standalone instrument that could be working in the background ?

Additionaly, testing with a new project, has this one been created from a template that could have a hidden instrument track in it ?

Beats me, everyone. I just restarted the computer (restarting Cubase hadn’t done the trick). And now it’s gone. What a strange glitch. I sorta wonder if the chord track was misbehaving somehow. Thanks for considering.