The second module in the Laboratory line is this ultra-clean filter. Once again, no attempt to imitate hardware was made with this completely original filter design. Instead, the focus has been on making the cleanest, brightest, punchiest filter imaginable. Thanks to the almost infinite resolution of double-precision floating-point arithmetic, this filter is absolutely superior in performance to any hardware filter ever made. Filters that distort are fine, but that usually means one thing: lack of dynamic range which means they grind, but they don’t punch, and in a mix they can sometimes just turn into noise and mud. Not so here. When you use this VCF in a velocity sensitive or other dynamically controlled way, you really hear the difference in how it cuts.
Like in the Laboratory VCO, output mixing gives you infinite timbres. For example, try turning up the lowpass output and add a touch of sizzle with just a little highpass. You hear sounds from this filter you have not heard elsewhere. And of course you can mix multiple filters into your next destination without the need of a mixer.
In addition to the 1V/oct input with +/- variable keyboard tracking, there are 3 variable modulation inputs, and because this filter is capable of ridiculous gain in some circumstances, there is an INPUT level control and a meter so you can keep things under control.
Cutoff frequency is controlled by a RANGE switch and the Fo knob. Resonance, controlled by the Q knob, goes from 0.5 to 4000! A Q of 4000 means that if you ping this filter at A440, it rings for over 10 seconds! Try that in hardware. The 2/4 POLES switch and QMOD input enable this filter to transform itself into a number of familiar types. The QMOD is a very powerful feature. For example, if you apply the same envelope to it as you’re using for frequency sweep, you can get more (or less) Q at the top of the envelope than at the bottom, thus imitating the behavior of a number of hardware filter qualities (and limitations). In LO RANGE, the Laboratory VCF makes an insane portamento control, giving you voltage controlled rate with overshoot and ringing if desired, as well as unique acceleration / deceleration curves.