This compact module will serve as four linear VCAs or as a four-input mixer — for audio or control signals.
Part of the reason Eurorack has such pulling power is that one module purchase leads, almost automatically, to others. Immediately after I began to enjoy a recent addition (the Studio Electronics Quadnic), it occurred to me that it would be cool to treat each oscillator to its own envelope and VCA. Since I have a decent collection of envelopes, I looked around and eventually settled on the ALM/Busy Circuits Tangle Quartet. At just 8hp, this compact module will serve as four linear VCAs or as a four-input mixer — for audio or control signals.
The first thing you notice about the Tangle Quartet is that it wastes absolutely no space. The four vertical attenuators are very close indeed to their respective CV inputs, which makes tweaking a pretty intimate and restricted affair. Fortunately that’s the only compromise in a module that, from the outset, ‘simply works’.
If judged as a collection of independent VCAs, the Tangle Quartet is blissfully quiet and noise-free, with no discernible crosstalk between channels. This even applies when you’re mixing and matching functionality, eg. two channels are used as VCAs but the remaining pair are a blender for control signals. Incidentally, mixing LFOs is an excellent way to turn simple modulation sources into something altogether more interesting, a feat the Tangle Quartet achieves effortlessly.
Separate outputs are provided for each channel, plus there’s a mix output too. Connecting any individual out removes it from the mix, so if you make use of all four, the main mix will be silent. Every channel has an LED that lights in proportion to the level of attenuation. With no CV inputs present, you therefore have a four-channel mixer with a visual overview of loudness. If you then feed in LFOs or envelopes to drive the attenuation, the LEDs supply a pretty accurate impression of the modulation shape — nice. Ultimately, the Tangle Quartet is a highly flexible utility module capable of a wide number of roles.