"I found these two on Ebay in early November of 2024. They are somewhat generic looking train keyboards by the brand Creatoy from 1995. Many toys made by Creatoy from this era, and similar toys like them have a special place for me. As a child of the late eighties and early nineties, I would see a lot of these lesser known toys at friends' houses, and school growing up. At the time, it seemed like there was no shortage of these off-brand obnoxious toys everywhere. Now they seem to be harder to find. When I have a little extra cash, I love to scour Ebay for these types of forgotten relics."
"The NTDD is a PT2399 based dual-delay(DD) processor, and analog Dub-Siren circuit.
DELAY: There are two PT2399 delay chips in series with independent delay time controls on the X and Y axis of the "TIME" joystick(Left). The delay-mix and feedback-amount are controlled together by the "ECHO" knob. The "REGEN X2" switch enables the output from delay-chip 1 to be fed back to its input, as well as to delay-chip 2's input. When disengaged, only delay-chip 2 will have feedback(echo). The Echo and Feedback circuits are designed more for experimental exploratory noise, and less for traditional audio processing. The delay times can go very low and become very distorted, and the feedback is set very high to allow maximal feedback and self-filtering with the use of auto-leveling. An optical compressor is used to prevent feedback runaway, while allowing lower signals to regenerate continuously. An internal trimmer resistor can be used to adjust the sensitivity of the compressor.
SIREN: The "Dub-Siren" consists of a square-wave VCO, gated envelope generator and LFO. The envelope generator is active while the "GATE" switch is held, and the "ENV"(envelope) knob determines the Attack and Release time when the Gate switch is pressed and released. The three position switch below the Envelope knob determines the Envelope knob's range. In the upper position, the Envelope knob will have a fast attack, and the knob will only change the release time of the envelope. In the center position, the Envelope knob range will be split between Attack and Release. Increasing the Attack time will in-turn decrease the Release time, and vice-versa. In the lower position, the envelope will have a fast Release time, and the ENV knob will only change the Attack time. By default, the envelope generator controls the volume of the square-wave VCO, but can also be used to modulate either the Pitch of the VCO or the Rate of the LFO with the "MOD" 3-way switch. In the center position, the MOD switch is "OFF". The LFO modulates the Pitch of the VCO. The LFO can be set to Square-wave or Triangle-wave with the "SQR-TRI" switch. The LFO Depth and Rate are controlled with the X and Y axis of the right joystick. The LFO voltage can be offset with the "BIAS" knob. While the LFO depth is set to minimum, the BIAS knob can be used to change the pitch range of the VCO independent of the LFO.
The NTDD also comes equipped with; Volume knob(VOL) Power ON/OFF switch with LED 1/8 inch(3.5mm) input jack 1/4 inch line output jack 5.1mm DC adapter(9V tip-positive) Built-in speaker 3XAAA battery compartment."
The Sine voice has a VCA knob, Distortion knob, and Pitch knob. The Distortion knob effects the waveshape of the oscillator. At the low end, the waveshape is triangular. Midway it is Sine, and at full, the oscillator is squarewave. The Sine VCA knob sets the offset of the VCA, and can be used as a volume mix knob when other modulation inputs are not in use. The Sine VCA can be modulated by any combination of the LFO, Pad EG2, and the Sine Pattern bank EG. The Sine Pitch knob sets the offset of the Sine VCO, and can be used as a pitch control when the VCO is not being modulated. The Sine Pitch can also be modulated by any combination of the LFO, Pad EG2, and Sine Pattern bank EG, however, the LFO and EG2 can only modulate one or the other; VCA or Pitch. Likewise, Pad EG2 can only modulate one or the other; VCA or Pitch. When Pad EG2 is set to Pitch, the Pitch knob sets the depth of the envelope. The Sine Pattern EG is triggered by the Sine Pattern bank. The envelope modulates the Sine VCA, and can also modulate the Pitch. The Bend knob sets the depth at which the envelope modulated the Pitch. The decay of the envelope is controlled with the Decay knob. The decay can be modulated by the LFO via the Sine Decay Mod switch, however the decay has to be set longer, as the LFO can only shorten the decay time of the envelope.
The Noise voice has all of the same VCA, Pitch, and modulation features as the Sine voice minus the distortion knob. The Noise voice is derived from a "LFSR" type pseudo-random-noise generator. The pattern length of the LFSR can be set to one of eight lengths. The shorter lengths are more harmonic, while the longer lengths sound noisier. When the LFSR Select switch is pressed down, the touch pads can be used to select the desired LFSR pattern length. A number below each touch pad represents the corresponding pattern length.
"Just a poor, brief walk through of just a handful of the percussive noises the Noystoise clone of the Synare can make. Apologies for the poorly scripted, off the cuff demo."
"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.
Published on Sep 17, 2019 Published on Sep 17, 2019
via noystoise where you'll find the full post with additional build pics.
"Got a friendly message from none other than Mike Walters of Mystery Circuits. He had been tasked with repairing an odd-looking synth that resembled something I would make. Sure enough, it was the heavily modified Yamaha PSS-30 I had built on commission some 8 years ago."
"This is a custom made sequencer synthesizer. All analog. Very fun to play. Lots of sonic possibilities to add to your mix. Unique VCO can be chaotic but very usable. Inspired by circuit bending. Can be synced to external gates, triggers, or clock sources, and can be used to gate or clock other things. Check out the video...
