From the Blacet website:
A Classic Sounding OTA Based Phaser with Extensive Voltage Control
- Four Stage Phaser with Dual Phase Regeneration Switch for “Classic” or Bright Response
- Input Level Control
- Voltage Controlled Center Frequency
- Voltage Controlled Regeneration
- Built in LFO
- Voltage Controlled Modulation Depth
- External Modulation Input and Mixer for LFO/External
- Dual Out of Phase “Stereo” outputs
- Very Low Noise Design
Download Blacet’s STONZ BASIC MANUAL.
Here are two more photos of the board and the back showing the unusual mounting bracket.