User guide

XONE VF-1 User Guide 9

Envelope follower to overdrive

Enables the envelope follower circuit to modulate the valve

overdrive so that the valve distortion/compression effect increases

dynamically with the music. Produces a subtle, interesting effect..

LFO Speed

Sets the speed at which the LFO (low frequency oscillator) will

modulate the filters, from a slow 0.2Hz (approximately 12BPM) to

a very fast 16Hz (960 BPM).

LFO Waveform

Selects the type of waveform that the LFO outputs to modulate the

filter. A triangle output will smoothly sweep the filter cut-off

frequency up and down, whilst a square wave will produce an

instant cut-off frequency change rather like a “gating” effect.

LFO Depth

Adjusts the level (or depth) of LFO modulation. Set anti-clockwise

for no effect, turn clockwise to increase the effect.

Resonance

The resonance control alters the way the filter behaves at its cut-

off frequency. With the control at minimum the filter will have a

gentle roll-off and therefore a smooth, subtle sound. At maximum

the filter will have extra gain at its cut-off frequency, greatly

emphasising any sound at this frequency.

Care should be taken when using the filter unit with the resonance

set at maximum as it may cause clipping in the signal path.

However the VF-1 includes an automatic resonance control (ARC)

circuit that reduces the amount of resonance at high signal levels

so minimising the likelihood of distortion. Also, the ARC circuit will

automatically reduce the amount of resonance at low frequencies

where there is higher energy level and therefore greater chance of

damage to low frequency speaker drivers.

When the two VF-1 filters are combined as a single mono

24dB/oct unit the amount of resonance will be doubled.

The diagram below shows the effect around the filter cut-off

frequency of increasing the resonance.

20Hz

0dB

RESONANCE

LOW

HIGH

MID

FREQUENCY 20kHz

CUT-OFF POINT