MATRIXSYNTH: Pink Noystoise NT-04 drone/sequence synth

Sunday, February 16, 2020

Pink Noystoise NT-04 drone/sequence synth

via this auction

You can find a demo of the Noystoise NT04 here.

"This NT-04 is one of ten handmade drone/sequence synths made by Noystoise in 2018. It has two oscillators, a low pass filter, simple decay envelope, and an eight step sequencer that can be sync'd with external devices such as a Korg SQ-1 or Eurorack modules.

It's a fun, weird, and sometimes downright squirrly little noise maker and to be honest I hate to part with it, but sometimes bills have to be paid.

This particular NT-04 is in excellent condition, never used outside the studio, and pretty much as close to brand new as a used item can get. That said, there is one issue that has been there since I received it, and that is that the yellow JOY button next to the pitch knob has a tendency to stick in the on position when released, but a light snap of the button when pressing and it will disengage it. This appears to be a quirk of the construction as it rubs slightly against the front panel when pressed. I mostly leave it in the on position anyway as the joystick only changes the pitch when one of the sequencer keys is touched at the same time.

There's a couple of things that aren't included/aren't clear in the builder's description below that the buyer should be aware of:

- the internal speaker is very quiet, and has a much narrower frequency range than the synth, almost to the point of being useless. It really needs to be used with an external amp or mixer to shine.

- the pitch knob and joystick only affect pitch when the rec button is on and a sequencer key is touched. When this is not the case, the key will stay at its last recorded pitch, no matter the setting of the pitch knob, joy button, or joystick.

Description from the builder:

Ok, so what's inside the NT04?

The NT04 is a programmable 8-step sequencer with 8 touch sensors, and one tuning knob. When you touch a sensor, the sequencer will jump to that step, and the step will be held as long as you are touching it. When you let go of the sensor, the sequencer will continue from that point. The sequencer can also be turned off with the run switch(run), and the touch sensors can be used like a keyboard. When the record button(rec) is on, and a touch sensor is pressed, that sensor's respective step will record the setting of the pitch knob(ptch). Each step has its own LED indicator. The sequencer can run in either direction depending on the up-down switch(u d). If the sequencer is in down mode, reverse mode(rvrs) can be enabled. Reverse mode is simply another clock signal that toggles the sequencer between up and down mode. The rate of the reverse clock can be set with the "rvrs" knob. Both the sequencer rate and pitch setting can be controlled with the Y axis of the joystick when each's respective "joy" switch is toggled. The sequencer clock rate can be modulated with the sequencer's recorded steps. The "sqnc" switch sends the CV sequence to the sequencer clock VCO for some weird swinging rhythms.

The sequencer modulates a pretty basic square-wave VCO (VB). VB has four modes; normal(3), -1 octave(2), -2 octaves(1), and XOR. XOR is kind of like a ring modulator but for square waves. VB is the carrier, and VA is the modulator(or vice-versa). VA is PLL VCO that tracks the frequency of VB. The tracking filter of the PLL is intentionally designed to be inefficient for its wild phasing, chirps, buzzes and other strange but consistent anomalies. The VA track knob adjusts the tracking filter from jittery-fast to portamento-slow. The VA tracking filter also has two additional filter modes, "B" and "C", which are really just different sized filter capacitors for more crazy ranges for the PLL VCO. If that wasn't enough, the PLL VCO also has four octave ranges that can be set with the VA "range" switch. VA-4 is matched with VB-3, and VA 3-1 are all octaves up. The VA tracking filter can be modulated by the X axis of the joystick when its "joy" switch is toggled. Both VA and VB are mixed together with simple on/off switches (VA and VB) before being sent to a 12db lowpass VCF.

The VCF has a cutoff knob and a resonance knob. The cutoff can be modulated by the X axis of the joystick if its "joy" switch is toggled. The VCF can also be modulated by a simple envelope generator. The envelope generator has an on/off switch and a decay knob. The depth of the EG is set to mid range, so the initial cutoff setting sets the overall range. When the sequencer is disengaged, the EG can be triggered by the touch sensors. The decay of the envelope generator can be modulated by the X axis of the joystick if its "joy" switch is toggled.

After the filter stage, the signal is sent through a volume control knob, and out to the speaker or 1/4 inch line out. The NT04 can be powered with a 9 volt battery or a standard 9 volt adapter. Additionally, there are two clock sync jacks. One is input, the other is output. The output will send either clock signals or trigger signals, depending on whether sequencer is in "run" mode or not. Any signal coming to the input will advance the sequencer whether the sequencer is in "run" mode or not, the only difference is that when in run mode, the input signal can trigger the EG. Any signal input will be sent to the unit's output, so syncing multiple units in series is possible."

1 comment:


©2019 Matrixsynth - All posts are presented here for informative, historical and educative purposes as applicable within fair use.
MATRIXSYNTH is supported by affiliate links that use cookies to track clickthroughs and sales. See the privacy policy for details.