Moving from mono to stereo sound: a logical progression for any synthesist looking to expand their sonic palette. Making use of two audio channels, rather than just one, quite literally adds another dimension to the capabilities of a synthesiser.

Unfortunately, controlling stereo signals can be a challenge within a modular system. This realisation led to the development of Enhance 2: a convenient yet high-fidelity tool for stereo enhancement. It can be used to adjust balance, width and spectral content, while also opening up a world of mid/side processing; all under voltage control and in just 8 HP.

The primary stereo parameters are balance (moving the sound left or right) and width (making it narrower or wider). The balance circuit uses a true constant-power gain law, while the width stage allows for seamless transitions from pure mono to extra-wide stereo.

In addition, tone control is provided by a pair of unique, wide-ranging mid/side voltage controlled tilt filters with selectable corner frequency. These make ‘cleaning up’ a muddy-sounding mix straightforward, but also provide unique binaural effects when modulated.

Mid/side processing encodes the stereo signals into one containing only the mono material (mid), and another containing the differences between both channels (side). Apart from the internal tilt filters, mid/side outputs also enable external signal processing such as compression or reverberation. An integrated mid/side decoder returns the results back to standard stereo. And at all times, a LED bar phase meter ensures that phase correlation can be easily maintained.

Stereo field modulation, mid/side equalisation and beyond; Enhance 2 brings true analogue stereo control to the Eurorack world.