23 Psychoacoustic is a new iteration of the original Psycho-Acoustic Sub Bass Synthesizer. No longer specific to Sub Bass, it is now capable of producing sounds in the sub audio range all the way to the ultra high frequency end of spectrum. Hybrid Electro-Acoustic Sounds, Sinusoidal Phase Shifting Oscillations, Deep Sub Bass, Piercing Rhythmic Drones, Ultra Low Frequency EMF Percussions are all there waiting to be explored via the free patching interface and 6 touch sensors. The pool for experimentation is deep.

The original psycho was based around 2 filters from what is historically been called the Twin T topology. It was originally invented for early telephone communication. As can be seen from schematic on the patent, it was called Twin T because there are 2 symmetric displays of components that resemble 2 T's - one with 2 resistors and 1 capacitor and the other with 2 capacitors and 1 resistor.



Circuit diagram illustrating Twin T topology from original patent 1944


Frequency Response Diagrams from Twin T patent


This filter when fedback upon itself is really good at producing percussive sounds. This is why most early classic drum machines were using this circuit topology for producing electronic kicks, toms, snares, claves, congas etc...



Depending on component layout and selection, the Twin-T circuit typically has somewhere between 2 and 4 octaves of frequency range available and the frequency response curve is quite non linear. Also part of the nature of the circuit is that all controls are interacting with each other to some extent. This might have been at least part of the reason why early drum machines had few editable parameters.

The frequency range for the Twin T is mainly determined by the capacitor values and on 23 Psychoacoustic there are 8 possible values - selectable with 3 switches or controllable by the 2 chaos registers.

The 2 chaos registers take 2 binary inputs- clock and data- and output 3 logic signals which can switch the capacitors of the 2 Twin T filters in a controllable randomized way. At the same time, the 3 logic signals are sent to a DAC where they are transformed into a stepped analog voltage (looped or free running) that can be used to modulate other sections of the synth.

23 is a fully modular synthesizer meaning that it must be patched before any sound will be heard. The various sections include

- 2 Twin T filters

- 2 Low Pass Gates for chopping up and effecting CV or Audio (with Attenuators)

- 2 Touch controlled VCO Pulse Oscillators (switchable between low frequency and audio range)

- 2 Chaos Registers

- Voltage Controlled White Noise with 3 filter responses

- Built In Contact Microphone

- Counter with /4, /16, /64, /256, /512, /1024 outputs

- 39 patch points, 6 touch sensors, and 5 assignable 3.5mm mono jacks

- All parts and solder used in the construction are lead-free and ROHS compliant

- Center positive 12v supply (not included)

- Dimensions 170mm x 177mm x 15mm (without knobs)

- Weight approx 500g

Comes with 10 alligator patch cables to get started

23 USER MANUAL