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.