When using varispeed for example +10 cents and i tune my guitar with the instrument tuner inserted as plugin in the guitar channel the guitar will be 10 cents higher than expected. Tuner is in auto mode
but it shows the same behaviour in freq mode.
Everything the tuner shows has a varispeed bias. But the reference in the display (of in my case 440Hz) is not changed when changing Ardour’s varispeed setting.
Is this the expected behaviour?
Gentoo Linux (kernel 6.9.9), Ardour 8.6.0 using ALSA ffado driver
I don’t think the x42 tuner is aware of any varispeed setting in Ardour, so you’ll have to set it to manual and then work out what actual frequency represents a 10 cent increase for the respective string and adjust the settings accordingly.
All processors or plugins in Ardour are not aware of varispeeding [1].
Varispeed works by resampling inputs and outputs.
Say you run at 200% speed. When rolling the following happens:
1 time-unit of audio is collected from the soundcard’s inputs, and then stretched to be 2 time-units long.
then Ardour (and all plugins) process 2 time-unitsat 100% speed.
the resulting 2 time-units are resampled back to 1 time-unit and played back on the soundcard.
When the transport is stopped, the vari-speed setting has no effect.
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[1] There is a extension that allows plugins to query wall-clock time and vari-speed, but I’m only aware of one plugin actually using that (repitch.lv2).
I made a short video with sound to show my experience:
you see ardour in stopped state, the varispeed control box and the tuner.
You hear the guitar channel.