ANALOG SYSTEMS TRIPLE OSC

via this auction
Cool logo case.
"Analog Systems 230V rack I put together and bought new. Its comprised of three Oscillators, Low Pass Filter Moog ladder filter for xtra warmth and fatness, VCA, Envelpe Generator and Mixer...

Go here for more super detailed info:
http://www.analoguesystems.co.uk/index2.htm

Modules Brief Description By Analog Systems UK.
RS90- Oscillator x3
"Most audio frequency oscillators generate a range of periodic waveforms. In general, these waveforms contain a large number of harmonics and are suitable for use as the basis of subtractive synthesis, wherein harmonics are removed or emphasised to create new sounds. (Some oscillators also produce aperiodic waveforms which are perceived as noise, but the RS Integrator has a dedicated module for this.)

These oscillators are the prime sound sources within a synthesiser. There are other sources - such as self-oscillating filters - but for the majority of applications the initial sound will be generated by one or more conventional oscillators. It is therefore vital that these offer accurate waveforms, are stable with respect to pitch, and that they suffer from a minimum of unwanted noise and/or distortion. They should also be very flexible, which means that they must be capable of producing a wide range of timbres. Finally, they must exhibit one further, but unquantifiable quality: they must sound good.

You may think that it would be straightforward to satisfy these criteria. Unfortunately, it isn't, and many synthesisers suffer from a "weak" or "characterless" sound. And, since analogue synthesis is subtractive you can't put back what wasn't there in the first place. The oscillator itself must be of the highest possible quality. Which leads us to the RS90... "

RS-100 Low Pass Filter_Moog type ladder filter VCF (LPF). New completely designed mk 3 ladder filter. Superb sounding low pass filter giving that authentic vintage Moog type sound..The most highly revered low-pass filter in analogue synthesis was developed by Dr Robert Moog in the late 1960s. It first appeared in the modular Moog synthesisers of that decade, but its finest hour came in 1970 with the appearance of the Minimoog. Largely because of its filter, this rather limited instrument has remained the standard by which all others are measured, and has survived nearly 30 years with its reputation intact as the most desirable of all integrated monophonic synthesisers.

Moog's filter used a circuit called a ladder network. In itself, there is nothing special about this, and many other filter designs are capable of emulating its response. However, Moog's circuit was flawed because it exhibited a small amount of distortion. Many engineers would have sought to correct this but Moog did not, perhaps because he recognised that the sound was musically pleasing. Indeed, if a synthesiser sounds like a Minimoog, it is called "warm" or "creamy". If it does not it will often be referred to as "thin" or "uninspiring".

The RS100 24dB/oct low-pass filter imitates the Minimoog's filter and exhibits almost identical characteristics in both the frequency domain (i.e. what it does to audio signals) and the time domain (i.e. its response over time to CVs). Below the cut-off frequency the response is approximately flat down to DC. With the filter fully open, it will pass signals approaching 20kHz.

RS60- Envelope Generator

IN USE
The RS60 Envelope Generator is a flexible EG that generates a four-stage ADSR voltage envelope that varies from 0V to +10V. The envelope can be attenuated and inverted if desired.

At their minimum values the A, D and R stages offer very rapid responses of better than 0.5mS, thus making the Integrator much 'snappier' than other analogue synths that often offer minimum attack times as slow as 5mS - 10mS. The S stage allows you to apply gains ranging from -×dB to 0dB (unity gain) to the steady-state level.

The RS60 offers a CV input that extends or shortens the Decay and Release times for sustained effects. There are also two switches that allow you to trigger the envelope manually, prevent it from re-triggering, auto-repeat once it has completed its profile, and so on. Modulating the envelope and using combinations of the retrigger switches allows you to generate complex envelope and low-frequency oscillations.

RS180-VCA
Logarithmic And Linear VC-Voltage controlled amplifiers (VCAs) are more sophisticated because they allow you to control the amount of amplification or attenuation by applying a voltage to a CV input. Such VCAs exist in every synthesiser that demonstrates the ability to shape a sound. You may think that it's the envelope that is, for example, changing the volume, but it isn't. The envelope is producing a CV that, when applied to the VCA, causes it to modify the signal passing through it. The VCA is one of the fundamental modules that allow us to make sounds develop over time.


RS-160 Mixer The RS160 is a 4-channel mixer with independent, linear response LEVEL controls for each input, and an overall LEVEL control for the output. Designed primarily for use with Control Voltages, you can use it for all analogue CVs and audio signals (mixing the two if desired) and you can invert the polarity of the output. These features allow you to create complex controllers for special effects, and are particularly useful for creating audio effects such as panning."