OSD, aka OR SUM DIF, is 3 independent blocks of useful utility in 4HP. 

OSD is centered around combining voltage in useful ways. Audio, V/Oct, and control voltage are at home in this utility. OSD offers a fully DC coupled signal path with precision components to make this happen.  High quality, configurability, and compact size ensure OSD will always find it's way into your patch.

- Combine v/Oct sequences with precision summing, or enable the the precision OR circuit for completely different results. 

- Mix two envelopes or an envelope and lfo using sum to create large accented voltages or combine with OR to keep the output  in the original range.

- Crossfade between audio or control voltage using the potentiometer in block one. Setting DIF will invert the signal at the B jack.

PDF MANUAL

What is OR, SUM, and DIF?

OR - Input voltages are compared and the higher of the two is passed to the output. 

For example if A = 4V and B = 8V, the output will be 8V.

SUM - Input voltages are added together to create the output voltage. 

For example if A= 3V and B=4V, the output will be 7V.  This clips at -10V and 10V.

DIF - B voltage source is subtracted from the A voltage, producing an output of the difference between the two.

For example if A= 3V and B = 5V, the output will be 2V.

Controls / Configuration

Block 1 - Sum, OR, or Difference of two inputs and effect the mix of the A input to the B input with the Knob.  The third input ORs with the result of the A/B inputs. Not a precision channel.

Block 2 - Sum, OR, or Difference of two inputs with high precision.  The third input ORs with the result of the A/B inputs.

Block 3 - 3 input OR with high precision.  Mix gates or CV from three sources for some wild results.

SPECS:

Size: 4hp

Depth: 40mm(with cables)

Power: 50mA +12V, 50mA -12V

All Inputs: >=100k ohm impedance .1% Resistors

All Outputs: 470 ohm impedance impedance compensated for precision.

20Vpp range