Wednesday 14 February 2018

Video #1: Sequential Prophet-6 great filters cutoff stepping? quantization? Nope! Harmonics!! Sweeps jam.

Video #1:

DSI Sequential Prophet-6 great filters cutoff stepping? quantization? Nope! Harmonics!! Sweeps jam. 

https://www.youtube.com/watch?v=DuquUtxDtj0


Description for this first video:
Pushing the filter on the Prophet-6. Not meant to be musical particularly! The steps in the filter cutoff frequency when the filter cutoff knob is turned on the Prophet-6 are an idiosyncrasy that a musician could use. Now I actually have a P-6, sometimes I can hear it, sometimes I can't. Sometimes I can just hear the harmonics picked out by the filter sweep and the filter seems to light them up audibly a lot, even to quite high frequencies. These can be clearly heard when using the low frequency oscillator (LFO) to sweep the filter slowly as you would expect. I love the harmonics generated by the P-6 filter and you can hear those speed and slow down as the cutoff goes up and down on a slow sweep. Sometimes they sound like stepping as they get closer together at higher frequencies. 

I'm now convinced that there is no quantization of the filter cutoff knob that you can hear. It is just the harmonic series and it rises in to an area densely packed with overtones. If you sweep the filter slowly and carefully through this region, you can hear the harmonic series as the overtones get closer and closer together until they are almost chromatic (but not quite). The eventually the overtones are separated by microtones and are not resolved by the filter, then you get a "smooth" rise and fall in resonant frequency. Basically the Prophet-6 filter is so good that it is resolving the overtones even as they are separated only by about 1/2 tone. The whole point of a filter is to emphasize overtones anyway. In Playing around with this, I have been able easily to hear overtones on a C fundamental note up to the 7th or 8th harmonic at least. Series goes C, C, G, C, E, G, Bflat, C, D, E, etc then going into into microtones. Note that is not chromatic but it might sound like it as the harmonic series gets densely packed. I've heard the B flat clearly and the C (7th and 8th harmonics) and then it goes into what sounds like a chromatic run followed by a smooth rise ad the reverse is true on a down-sweep. This filter should be a musician's paradise and that's just the low pass one! If you play chords, you are gonna hear far more overtones especially if the filter cutoff key follow is on FULL (or weird ones if it is on HALF) because each voice's filter will have its own different resonant frequency. You can hear chords of overtones stepping up, which in my view is mega cool.
However, with the resonance a bit lower, at 8 for instance, the bandwidth of the resonance is a bit wider and the sweep effect is smoother and I would say this is to be expected. It gives the player the opportunity to use the filter at high resonance (high Q) to pick out overtones individually and get some fascinating sounds. Great tuned percussion for instance and all sorts of amazing blips and bloops are dead easy to get on the Prophet-6, with just the filter, even using no velocity, no aftertouch, no wheel, no polymod, just this kickass filter. One might ask what is wrong with the synths that don't show this "quantization" (that isn't)...?

Arpeggios:
I think you can hear filter cutoff "quantization" at 
0:53(?), 1:03 onwards, 1:44 (cutoff knob) (but it is just closely placed overtones being resolved)
Seemingly smoother adjustment of filter cutoff at 3:30+, 4:18+.
2:18 onward, heavy resonance with faster LFO and cutoff knob too. Spot the "quantization" and the bubbling effect at 2:58. Mean.

Single notes: 2:58 with - harmonics  filters swept 3:43+. Octaves and fifths around 5:00+.

Chords with LFO and cutoff knob adjustments: 5:40+
At 6:06, 6:11(?) it starts to get confusing as to whether it is a quick run of harmonics.
Chords with LFO filter sweep:
You can hear harmonics super clearly around:
2:11, 3:39+, 5:16+, 5:30?, 
5:37 (high harmonics or quantization? - You tell me)
More harmonics 5:47, 6:00+, 6:27 run of close harmonics,
6:35+, 6:50, C major/F 7:02+, 7:18+, 7:28+, 7:44 (resonance to 9+) - this was too much fun!
8:10 and beyond.
High pass filter starts to come in after 9:00 somewhere and then at 11:08+.

The great thing about the Prophet-6 is that the filter and amplifier envelopes are right next to each other, one above the other making it a breeze to change them so quickly and in subtle ways.
The video after 8:55 is  2 short lots of messing about with the filter and amp ADSR envelopes and tweaking the filters low pass and high pass including resonance for some ear splitting treble - notes generated by the arpeggiator of course.
Totally gratuitous but this is why owning a synthesizer is fun, to experiment with the sound of music. Real time control abounds on the P-6. It's an abundance of riches as far as I can see.
The stepping seems to depend on whether the filter is in self oscillation. but I don't really care. You can get real smooth filter sweeps lots of other ways.  Maybe there is a deliberate stepping of the self oscillation to enable the player to tune the self oscillation easily, as with the ordinary oscillators?
You can hear it plainly in this video in a couple of places and it gives a bubbly effect, really insane if used as an asset instead of a problem.
Filter sweeps and adjustment of controls in real time to give an idea of the range of sounds from the filters of the Prophet-6.
Real time jam, recorded to tape, played on a car stereo and recorded using a digital SLR camera, so some bass will be lost.
Slight on board digital delay effect. I as just messing about with the controls so I didn't take this effect off. It doesn't make much difference. All the same, you can still hear most of it! The treble is quite severe because I was pushing the resonance high. I didn't notice any quantization on using the high pass filter cutoff knob. Maybe that is because the high pass filter doesn't go into self oscillation.
Scene is of a cat in an untidy garden. Something catches the cat's attention at 3:02. I can't imagine what.
Now it's time to make some actual musical sounds!
Video file: MVI 7336/-

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