Overview ................................................ page 1 Mono Mixer Detail ................................ page 2 Mono Mixer Quick-view ....................... page 3 Stereo Mixer Detail/Quick-view .......... page 4 Amp Biasing Feature ........................... page 5 V-CV Expander ..................................... page 6 Design Philosphy ................................ page 7-9 Tech Specifications .............................
1 Overview Vortices is an audio character mixer designed to emulate and accentuate the saturation-compression effects and frequency response of vintage analog consoles and tape machines. Featuring a total of 14 inputs and 7 outputs in a relatively compact 16hp form factor (18hp with VCA CV expander). Vortices was designed to offer a compact mixing environment with the characteristic sound coloration of vintage analog gear.
2 MONO MIXER DETAIL AUDIO INPUTS The Mono Mix bus features 4 main mono inputs, each with a level/saturation control via the mini-pots. Nominal volume level is set between 12-2 O'clock (assuming 10Vpp input) and saturation-compression level can be increased beyond this point. Inputs 1 & 4 feature manual and voltage control over stereo panorama (PAN). Inputs 2 & 3 feature manual and voltage controlled cross-fading (X-FADE). The PAN and X-FADE functions feature unique linear pan/fade laws.
3 QUICK-VIEW: Mono Mixer Bus Mono Mixer: Audio IN/OUT C A B C D D C B Main Monophonic Inputs 1, 2 , 3, 4 B Auxiliary Monophonic Inputs 1 & 2 Split Stereo (L/R) Direct Output of the MONO MIXER Bus Direct X-FADE output for Channels 2 & 3 (Breaks normalization to all Mix Outputs) A A A A Mono Mixer: Controls A B C Attenuation, Saturation and Gain Channel 1 & 4 Pan Controls Golden Arrows pointing from Pan CV Inputs Channel 2 & 3 X-FADE Control Golden Arrows pointing from Fade CV Input C B A
4 STEREO MIXER DETAIL AUDIO INPUTS The Stereo Mix bus features 3 main (L>R normalized) stereo input channels with attenuation and gain. The coloration offers a less pronounced saturation-compression effect compared to the mono mixer. Nominal level control is set around 3 O'clock with additional gain available beyond this point.
5 AMP BIASING FEATURE The biasing feature emulates Class-A tube and transistor amplifier tuning. Biasing is a symmetry adjustment that sets the quiescent operating point of a tube or transistor in order to achieve a linear response with least distortion. By increasing the bias (DC offset) a tube/transistor can be pushed into asymmetrical saturation.
6 V-CV EXPANDER Vortices CV expander adds voltage control of the signal levels for the 3 stereo and 4 mono main inputs. The switch located near the expansion header, between the panel and PCB must be set in the EXP position when the expander is connected. The supplied 10pin cable must be connected in the same orientation on Vortices and V-CV. Red stripe down. With V-CV connected the functioning of Vortices remains the same.
7 DESIGN PHILOSPHY In this section I will describe my intentions and inspiration for creating Vortices. Particularly in respect to my choice of layout and features and influences from artists and my own experience in using modular synthesizers. Users often question why module manufactures choose to make certain design choices. I personally have struggled with striking a balance between choosing the size and feature set when I design Eurorack modules.
8 If you have read some of the above references or are already familiar with the specifics of these saturation and frequency response characteristics in use, we now point out that the mono and stereo sections of Vortices exhibit alternative severity of these effects. The intention behind this choice is inherent in modules that one may be using with Vortices.
9 When a signal distorts symmetrically, additional Odd Order harmonics are produced, specifically third order up from the fundamental frequency dominates, with the successive 5th, 7th harmonics appearing in reduced amplitude. Odd Harmonics are known to have enharmonic qualities. One example of this would be a square wave, which consists of a summation of only odd-order frequencies. See the Fourier Analysis section of this wiki article if you are unfamiliar with this concept.
