via this auction
"Sealed OP-1 unit as sold by Teenage Engineering. Never opened, never played. You get to break the seal (be sure to use exacto for a clean look, the box is your case) as the unit is still in the sealed box."
EVERYTHING SYNTH
Ports 1 to 8 are CV able and you can select the maximum voltage for 5V or 10V for signal output:
2. Gate function: Activate by note_on/off for one note or for each note. The voltage output could be select of constant 5V or 10V or variable with velocity value (note_on).