The ADDAC270 Intuitive Quantizer

Information about the ADDAC207 Intuitive Quantizer was published on the ADDAC website some time ago, but they've started selling it only recently. It fills the gap between simple quantizers like the Doepfer A-156 or the Analogue Systems RS-260, and more complex beasts like the Analogue Systems RS-130. The user interface looks a bit like the Intellijel designs uScale but the ADDAC is more versatile.

Quantizers are typically used to process the cv-output of an analog sequencer, either correcting/tuning the cv values, or using advanced options to filter out certain values for creative effects. You can also quantize continuous controllers like a Theremin or feed an LFO, random noise, or any other cv-signal to the cv-input. Think of it as an autotune-plugin for modular synths ;-)

If you want creative harmonic effects, the Doepfer A-156 is really a bit too limited. The hard-wired 'major/minor' and 'quint/chord' options are frustrating. The Intellijel designs uScale v2 could be a good choice, but the ADDAC207 is even better because it has 4 cv-input/outputs which allows for advanced harmonic effects.

Keep in mind though that for 'clean' harmonies you will have to process each VCO seperately (dedicated VCA). This way you avoid unwanted frequency modulation, which can result from adding up the raw signals of various VCO's in one simple mixer module. You'll also need high quality VCO's with good 1v/oct response, properly calibrated and well warmed up. Keep your VCO's in tune during a recording session with a quality tuner, for example the Korg DT-3.

Xenharmonic options
Check out the user guide for the advanced options of the ADDAC207. A nice surprise are the xenharmonic options. Not all temperaments offered here are equally useful though; the Bohlen-Pierce scale seems a bit overrated, and the African Temperament (a.k.a. Exotic) is a waste of resources, but there's also an option to put more than 12 steps in a scale, which is referred to (p. 22) as 'microtonal scales', although it's really a function to fine tune 1v/oct response per voice in really small steps of 0.001mV which means it's not very practical to retune to - say - 23 edo since every voice has to be retuned, and these settings are not stored as preset. Too many hurdles really.

This 'microtonal' function is just like a trick that will work with any quantizer. If you attenuate the signal that comes from the cv-output, you can divide an octave in 13, 14 or any other number of steps. Although the number of steps you can program on the quantizer itself remains the same, the good news is that there are usually 12 of them (unless you use an A-156). This means that you could skip one, two, three, four or six steps. A good starting point for symmetrical scales in even-numbered equal temperaments, with lots of possibilities to explore if you push a few extra buttons. And if that doesn't work for you, why not try switching from Moog standard to Buchla standard.