The unstoppable Allen & Heath have done it again! Taking the much loved filter section out of their award winning Xone mixers and into a stylish 1u rack mount unit. The VF-1.

Filters: three different filter types are provided: high-pass, band-pass and low-pass, which can be selected together to create further types - for example, high-pass and low-pass together create a notch filter. All of the filter controls are "soft switched" to prevent clicks, allowing them to be changed on the fly

Resonance: this control allows the sharpness of the filter to be adjusted from a gentle roll-off for a subtle filter sound, to near oscillation at maximum. Automatic Resonance Control (ARC) monitors the output of the filter and automatically reduces the resonant peaks of high signal levels, thus minimising potentially system-damaging transients

Mono/stereo: the filter can be configured as a stereo 2-pole (12dB/octave) or a mono 4-pole (24dB/octave) by selecting the Mono switch on the rear panel, without the need to re-patch

Invert Filter: Another rear panel switch sums the inverted filter signal with the non-filtered input signal and routes the remainder to the TRS jack outputs; this can give some unusual and subtle sounds, especially if routed to an effects unit

Valve: as well as the VCA filter the VF-1 also has a valve (tube) input stage with drive control, allowing the signal level through the valve to be progressively increased in order to create strong second harmonics, or taken all the way into clipping. This is a great tool for adding warmth to a mix or for fattening up thin, reedy bass sounds. Automatic gain reduction circuitry maintains a near constant output level as the overdrive control is increased

Envelope Follower: this function with switchable release speed, allows the filter cut-off frequency to be modulated by the intensity of the input signal, and can be used to create some interesting effects with drum loops and bass lines. It can also be switched into the valve overdrive circuits to give intensity modulated overdrive

LFO: the low frequency oscillator with square/triangle waveforms completes the modulation toolbox for the filter system

MIDI: the VF-1 can send and receive MIDI, allowing the filter frequency, filter type, and on/off status to be remotely controlled or saved to a sequencer. It can be configured to operate in several different modes; for instance, to allow it to interface to our MIDI equipped XONE:92 DJ mixer, and another to track the filters to MIDI notes