Dorico and GrandOrgue distortion problem

Hi, I am having a problem with Dorico and the virtual organ simulator GrandOrgue. Any help would be much appreciated.

I have been using GrandOrgue along with Piotr Grabowski’s excellent free organ sample libraries, and I discovered that GrandOrgue is not a VST and therefore requires a virtual MIDI driver like LoopMidi. I was able to set it up and get GrandOrgue playing with Dorico, but when I select a note and press P to play from that selection, it quickly makes horrible distortion sounds and the data in LoopMidi skyrockets and mutes from being overloaded. After that, I am unable to get it to play as it should again without restarting the whole process.

The weird thing is, if I set it up and play some music from the beginning, it works. It only distorts if I play from a selection, but after that it doesn’t play correctly either way. Here is some information about my setup:

LoopMidi Port Name: GrandOrgue

GrandOrgue Sample Size: 24 bits
GrandOrgue Sample Rate: 48000
GrandOrgue Samples Per Buffer: 1024

Dorico ASIO Driver: Generic Low Latency ASIO Driver
Dorico Sample Rate: 48000

Does pressing “P” mean something in GrandOrgue (or LoopMIDI) that affects your playback?

I tried using GrandOrgue a while back, and the first attempt failed because it wasn’t recognising any note-off messages from Dorico.

There was some tweak to the GrandOrgue MIDI setup that fixed this, but unfortunately I can’t remember what it was, and I haven’t used it since for other reasons. so I’m not going to dig it out to investigate just to answer the questions fully - sorry!

IIRC I had to go into GrandOrgue’s “MIDI learn mode” to teach it what MIDI messages started and ended notes, or something like that. It was probably the choice between “note off” messages or “note on with velocity zero” to end notes.

Certainly it would be worth going to the Play page of Preferences and clicking the ‘MIDI Input Devices’ button to make sure that Dorico is not listening for input on the same MIDI port you’re using to communicate with GrandOrgue.

That seems to be it! It’s ticked by default, so I thought it needed to be ticked for it to work. Quite the opposite! Thank you.