Chris,
Thanks for the kind words about the Quaverato.
To give the Quaverato “deeper” depth you can increase both tone trim pots the same number of turns to get their individual signals louder (turn them clockwise). Just make sure you increase the same number of turns on each pot to keep the same hi-to-low ratio. You may have to turn down the gain trim pot to make up for the increased volume.
Another thing you can do is to make sure there is no light getting into the optocouplers. Make sure there are no tiny holes in heat shrink (from the soldering iron shrinking the tube), especially on the LED side. I often use opaque black hot glue to cover the ends to ensure no light gets in.
Also, make sure you keep the harmonic mix knob at 12:00…make sure your knob is attached to the proper location on the pot otherwise what you think is 12:00 might not be.
Generally, the slower the LFO, the more pronounced the phasing effect will be. This is because the LDRs have a finite time it takes them to go back up to a high resistance after the LED has turned off. Slower LFO rates give the LDRs time to fully recover to their “off” resistance.
I hope this helps.
Good luck!
-Brach