Foxtrot Duo is a stereo multimode filter with three different classic filters - virtual analogue models taken directly from the circuit diagrams of the originals.

The three models are:

1) A ladder (LD) filter from the classic MOOG designs from the '60 and '70s
2) A Sallen-and-Key (SK) filter based on the Korg 35 module used in the MS-20
3) A State Variable (SV) filter as used in the Oberheim SEM

Each filter type sounds very different, with their characters really coming out with increasing resonance.

The ladder filter has that great, squelchy Moog sound. Switch to SK and you get a pretty clean Korg character when the resonance is low, but turn it way up and the filter screams and howls. In contrast, the SV filter is bright but smooth and velvety.

All three filter types produce Low Pass, Band Pass and High Pass responses which can be morphed between using the front panel control or CV.

Foxtrot Duo - as the name suggests - can be switched from a single mono filter to a stereo pair.

In Mono mode, the two inputs are summed together, but in Stereo each input is routed through its own filter to the right and left outputs.

The AUX CV input can be switched to allow CV control of the filter response, resonance or, in mono mode, the pan of the dual outputs.

In stereo mode, this pan setting controls the cut-off frequency of the two filters separately. A positive CV raises the cut-off frequency of one filter and lowers the other, and vice versa.

Like the originals, Foxtrot Duo's classic filters sound really great when overdriven, so the front panel also includes an overdrive 'Boost' switch.

Specifications:
Width: 10HP
Depth: 22mm excl. power cable. Approx 32mm inc. shrouded power cable
Power Requirements:
+12v: 200mA
-12v: 50mA
+5v: 0mA

Inputs:
Signal (Zero attenuation): + / -5v nominal, + / -12v max
Cut Off CV Left [Zero attenuation]: Volt per Octave
Cut Off CV Right [Zero attenuation]: 0-5v nominal
Aux CV [Zero attenuation]: + / -5v nominal

Outputs:
Dual / Stereo: + / -5v nominal, + / -11v max