Grove Audio has introduced the GMS-214 Multimode Filter, a 5U module that offers 15 different filter modes, plus voltage-controlled resonance.

Here’s what they have to say about it:

The filter is similar in design to the Oberheim Xpander filters. There are fifteen filter selections which are 1P LP, 1P HP, 2P LP, 2P BP, 2P BNotch, 2P HP, 3P LP, 3P HP, 3P Allpass, 4P LP, & 4P BP. There are 5 additional selections that add an additional one pole lowpass.

Filter resonance is controlled by a front panel knob and there is a resonance CV input that has an attenuverter to set the polarity and level. If the resonance control is advance far enough, the filter starts to oscillate with a sine waveform. The fidelity of the waveform is somewhat dependent on the particular filter mode being used.

Three CV inputs are provided:

• A 1V/Octave input controls the filter cutoff frequency in conjunction with the panel frequency control.
• A second frequency CV input has a level control, the resulting voltage being added to or subtracted from the base cutoff frequency resulting from the panel frequency control and 1V/Oct inputs.
• A resonance CV input followed by an attenuverter is combined with the panel resonance control to determine the amount of resonance that will occur. If the resonance control is turned past about 80, the filter will start to oscillate with a clean sine waveform.

Pricing and Availability

The Grove Audio GMS-214 Multimode Filter is priced at $275. Grove says that pre-orders will open tomorrow and be open until the end of the month, with delivery occurring at the end of July. If there aren’t enough pre-orders, the module will still be made available, but it will have a standard panel instead of a metalphoto type panel. The pre-order will be a $50 returnable deposit and the final price will be 10% off and free shipping for those who pre-order.