Standard Filters

The opcodes for standard filters are areson, aresonk, atone, atonek, atonex, biquad, biquada, butbp, butbr, buthp, butlp, butterbp, butterbr, butterhp, butterlp, clfilt, filter2, hilbert, lineto, lowpass2, lowres, lowresx, lpf18, moogvcf, port, portk, reson, resonk, resonr, resonx, resony, resonz, rezzy, svfilter, tbvcf, tlineto, tone, tonek, tonex, vlowres, and zfilter.