Free State FX FSFX115 Teezer Thru-Zero VCO

The Free State FX FSFX115 Teezer is an analogue Thru-Zero Oscillator in MU / 5U format that was originally designed by electronics guru Ian Fritz.
Teezer is the first thru zero oscillator module by Jason Fry at Free State FX, its simple implementation and seemingly sparse front panel hides a wealth of complex and unique timbres.
 It’s thru zero design allows for a much wider array of possible timbres and tones to be generated. Standard oscillators only allow for positive frequencies to modulate the oscillator core during FM, a thru zero oscillator lets negative frequencies effect the action or timbre of the sound, allowing for double the amount of possible harmonics and modulation results.
The front panel consists of five pots, seven jacks and a single switch. There’s a coarse frequency control, separate attenuators for both linear and exponential FM, a 1 volt per octave input, a sync input with variable sync settings and three waveforms outputs, including triangle sharktooth and sine (for the best FM results!)
There’s also switchable assignments for CV of audio (AC DC) on the linear FM, allowing for much more versatile tracking and more versatile sonic results.
The main features of the Free State FX FSFX115 Teezer include

Analogue Thru Zero Oscillator
2 MU units wide
.com power connector
Multi turn pots for incredible control over the VCO’s stupidly wide range
Switchcraft jacks