## Description

Improved version of the high performance Thru-Zero Oscillator OMEGA-PHI.

What has been improved?

Firstly, the VCO core:

– Parasitic noise effect especially audible at low oscillator frequencies at the Omega-sine/tri outputs exactly when the thru-zero operation begins to start by FM-modulation through a sine modulator is reduced by 15 db and is so no longer audible! BTW: a similar noise at the Phi-sine/tri outputs was not reduced!

– Highly improved oscillator FM-stability;

a) New precision rectifier design leading to terrific in-tune FM synthesis over the full index over a very wide frequency range.

b) New core-symmetry circuit for a perfect balanced triangle wave eliminates tendencies to asymmetric tri/sine shapes even at high FM-modulation frequency/carrier frequency ratios. This leads to no more carrier-sine distortions and no detunes even at high ratios.

c) Improved thermal board design for better frequency stability and linearity at very high frequencies and thus more stable FM results, generally.

– Extended maximum FM index from 44 to now 50.

Secondly, the VCO environment:

– Completely new VCA design for FM and PM providing ultra-low noise and ultra-low control feed-through capability.

– Ultra low constant or transient frequency shifts with varying FM indices in both modes, DC and AC.

– Cleaner sound, especially for PM and also for FM at higher oscillator frequencies, where VCA noises become relevant.

– Smoother VCA-index curve for better control even around zero reduced potentiometer noises for PM Phi (-360- – +360-).

The current thru-zero2 ω-δφδτ high performance vco omega-phi of the cs-8 series is a so-called thru zero oscillator to the power of 2. oscillators of this type are able to process negative control voltages (thru zero) to produce “negative” (phase reversed) frequencies.

With that technical difference to normal oscillators there are arising extremely significant properties! In comparison to normal oscillators for thru zero oscillators the modulation result will be kept harmonic independently of the modulation depth (index). In other words true fm synthesis is possible with that!

The ultimate feature of the omega-phi, moreover, is the capability of an additional true phase-modulation section. It is connected downstream to the oscillator core.The sound aesthetic is very similar to FM. Because of the downstream architecture the possibility of simultaneously processing sound synthesis arises to create pm sounds (phi section) and having at the same time clean standard waves at the core outputs (omega section) for further synthesis. A lot of potential is given by that!

Moreover, there exists a number of synchronization possibilities, very interesting intermediate states between “thru zero” and “normal”, a by one octave decimated sub frequency wave and apart from pwm a mighty phasing effects producing saw-tooth wave-shaping with 1-2 octaves-up effect as well as at last a super quite sine-wave.

Furthermore, the frequency range can be selected very quickly and reliable by a 4-pole rotary switch and a toggle switch over seven octaves and from there another ±1 octave, as well as ±100 cents. the finally frequency range reaches from a couple of hundred seconds to umpteen kilohertz (fmin = 0.001 hz to fmax = 300 khz).

The oscillator has, thanks of absolute high-tech-components, a very high octave linearity, finest temperature stability and because of its extremely low phase-noise (jitter) an extraordinary pure and powerful sound.

Design and implementation meet highest technical standards concerning usability, sound quality, and electromagnetic immunity. the entire design and production work was done in germany.

Or… in layman’s terms, it’s a nice VCO.