User Manual

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 synthesiz-
ers.
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.
When it comes to mixers I have always found it challenging to make choices based on the somewhat standard
requirements and the rack space they ultimately take up for a relatively basic function. Vortices was designed to
capture a list of the most basic needs of a mixer as well as offer extra use features while taking up a small amount
of rack space. These requirements included the ability to pan both manually and via voltage control, the ability to
cross-fade two sources and to accommodate both stereo and mono sources including extra inputs. Additionally, I
found that I always wanted a way to use a mixer in more of a modular fashion through the ability to separate the
mono and stereo sections to use them as sends while having the option to use either as the main mix output.
The second half of the design equation stems from the fact that while extremely useful, mixers are also a
somewhat boring necessity. This is where the character aspect comes into play. Some are familiar with my love of
the analog philosophy and inspiration from the pro audio world. The use of vintage audio consoles and analog
tape for the “magic” they can impose on a mix or instrument is now a widely known phenomenon. Although
some have gone to great lengths to attain these machines for exorbitant prices, the effect is far from snake oil.
Here is a great
article from Sound on Sound for further reading about how and why vintage analog equipment
exhibits this effect in music production.
Vortices was designed with intentional gain staging and high frequency tone shaping to both mimic and
accentuate the effects of over-driving and biasing vintage audio equipment involving tube and transistor circuit-
ry as well as the saturation-compression effects of magnetic tape in order to highlight the benefits that these
devices are so well sought after for. The ability of vintage analog equipment to glue a mix without the need for
compression while adding subtle to more apparent harmonic content is not restricted to pro audio and fits in
quite well in the modular synthesis environment. Furthermore, the response of these devices lend heavily on the
more modern techniques of feedback that have been popularized by artists such as
Empyset and are gaining
ground in the experimental modular synthesis microcosm. You can find a discussion of Emptyset's feedback
techniques from the Eurorack community here.
Inspired by the characteristics of both vintage analog mixing consoles and magnetic tape machines, the
concept is realized in a simulated signal chain where we have a virtual console as our input section, which is then
fed into a tape machine for final mixdown. Every channel exhibits a simulated headroom. You can think of them
as console/tape inputs that are nearing the headroom limits of those devices and therefore ready to be pushed
into saturation and clipping. This effect mimics the physical limits of these vintage devices. Both the Mono and
Stereo channels max headroom is approximately 12Vpp. This limit is post input level control and can be tailored
to almost any input level to remain clean if desired. However, we intend that you do push these limits when
desired.
The headroom limits are met with a hard-peak limiter, not unlike the simple safety limiting devices
employed in vintage gear. Here you will find another level of distortion with a crunchier hard clipping effect in
contrast to the more general, softer saturation compression akin to over-driven analog tape. You will find it much
rarer to hit the headroom limit in typical use unless intentionally overloading the input or applying one of the CV
offset techniques described in the Amp Biasing section. So, you can think of Vortices as a mini vintage studio, a
feedback hub or simply as an effect or tone shaping device.
Although we have focused on the above vintage characteristics, we have opted to skip any emulation of low
fidelity effects from these devices and continue to employ the use of pro audio grade components throughout.
DESIGN PHILOSPHY
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