Announcing Sapphire Env: a pitch detector and envelope follower

I’m pleased to announce the release of Sapphire Env for VCV Rack.

Env is an envelope follower and pitch detector based loosely on the ones inside Surge XT TreeMonster. Env uses a similar algorithm to TreeMonster for detecting pitch: both count samples between zero-crossings of the input waveform. Both use a prefilter to help focus on the fundamental frequency of the input audio.

However, Env uses a different prefilter than TreeMonster. Env uses the same Cytomic filter as used by the Sapphire modules Sauce and Gravy. Env has a wider range of speed ranges than TreeMonster for adjusting how quickly changes in pitch are tracked.

Env has the same ENV (amplitude) and V/OCT (pitch) outputs as TreeMonster, but Env also includes a GATE output that can be toggled between active-high and active-low modes, to indicate whether a pitch is being detected.

Here is a demo video where I use Env to estimate the pitch of a “plucked” Elastika, which is then mimicked by a Venom VCO Unit voice.

Here is another video where I use a pre-release version of Env to follow the pitch of a Tube Unit:

I hope Env will be useful for people to use a microphone to feed voices or real musical instruments into VCV Rack as a way of controlling the pitch and envelope of a modular synth voice.

I also believe Env will be useful for working with some of my physical simulations such as Elastika or Nucleus that are not traditionally tunable.

Thanks to @baconpaul for the original idea for this project, and for guidance and conversations to help implementation. I’m also grateful to @DaveVenom and @Omri_Cohen for early testing and feedback.

I will be interested to receive feedback about how Env performs, where it can be improved, or any problems you encounter with it.

23 Likes

Looks great, thanks!

1 Like