The 24dB FILTER is a 4 pole-filter with a slope of 24dB. Each pole is phase shifted by 45 degrees at the cutoff frequency giving you a phase shifted signal of 180 degrees. If the signal is then phase inverted once more you gain another 180 degree and when fed back into the input of the filter the signal is phase shifted by a total of 360 degrees. At this point a time delay occurs between input and output and at the point of the cutoff frequency there appears a very strong resonant peak. The first 24dB analogue filter was originally invented by Dr. Bob Moog. With the 24dB FILTER you can also create band-pass, low-pass and high-pass filters that use phase cancellation to shape the cut-off frequency. Using two oscillators you can spectrally crossfade through the frequency spectrum. Filter distortion, or so called ‘tube distortion’ is achieved by using FM feedback.