v1.0.0
We have given the DRIVE control a fair amount of range as increasing it didn’t remove any settability.
That being said, the DRIVE control is used for many things, including some volume adjustment. As
you approach 10 o’clock and beyond, more distortion of the waveform will occur. You may note that
well beyond noon, transients may be lost - this is because the waveform already contains lots of
higher order harmonics and are effectively masking the addition of more transients.
EQ’n
The EQ section of the instrument is extremely powerful and is composed of a 2nd order HPF and a
Gap Filter, which contains a 2nd order LPF into a HPF to create a variable width gap in the spectrum
of the audio. You will find many fruitful interactions between the EQ section and the other controls
of the module. Because we liked and built-in some codependence, you have to remember that the
EQ is capable of completely removing certain transient frequencies and enhancing others.
The Gap Filter is a highly efficient way to EQ the drum signal with minimal controls. It’s a LFP (LOWER
control) feeding a HPF (UPPER control). We originally designed the Gap Filter with two controls:
position and span, where the HPF was fed the same position control signal as the LPF, creating a fixed
pivot for span to widen or shrink the ‘gap’ of the filter (think of the gap as a variable width mid cut).
While this seems to make logical sense, through testing we found that the EQing process was more
fun and musical having them unlinked which can give useful filter overlaps for not only cutting
frequencies, but also boosting some. You may want to keep this in mind as you move the controls
around. If you move the LPF cutoff frequency, the gap width will also change. If you move the HPF
cutoff frequency, the gap width will change. But don’t worry too much about this as turning the
knobs and listening is the best way to EQ the tone.
MEOW
What the heck is MEOW? The name came from the way it sounds with high levels of pitch decay and
portal drive… Technically speaking, MEOW controls how much of the inverted pitch decay envelope is
fed into the drive circuitry. The more MEOW, the more the sound will increase in volume and
harmonics over time (the bloom time controlled by the PITCH DECAY time). This ended up being
quite a bit more useful than we’d originally thought because it allowed the beginnings of the drum
sound to be more subdued and the drums started to slip into a mix a bit more effortlessly but
without removing the punch and attack the pitch sweep provides. We find MEOW makes most sense
to adjust in context with the rest of your music.
Ticks, Clicks, and Transients
A key point in the design of Portal Drum was to create a phase correct instrument over the sweeps of
all controls. All tonal shaping happens in serial fashion and no additional signals are mixed along in
the drum. Keep in mind that transients are affected by the decay time (when the decay of the
previous hit is still ringing out), the GAP Filter, pitch decay, and the DRIVE amount. When DRIVE is
very high or the the signal is filtered in certain ways, you may not hear transients or they may be
‘maxed out’ by the other parameters (like DRIVE).
