Rob, it seems that the principle that lies behind the Alembic PU system lies in the fact that the tone of a traditional passive pickup is defined by its inductance and the way it interacts with the tone control.
Knowing that a pickup is nothing more than an electromagnet (ie: a coil around a magnet who can senses steel strings movements and translates it to voltage fluctuations), its inductance is basically defined by the number of wire turns that forms around the coil. This is what defines signal level: larger the coil, greater will be their inductance, thus generating a stronger signal.
However, greater the inductance, the more it will resist to the passage of high frequency signals and this means that a stronger pickup will produce less highs (you may say it'll sound less open or more muffled in way). So every pickup has its characteristic cutoff frequency above which all highs decays.
At the same time, as it passes through the tone pot, the signal has to face a capacitor and the interaction between inductance and capacitance will create a resonant peak right on that cutoff frequency. And guess what? Depending on the pickup, pots and capacitor chosen for use in a particular guitar, its tone will show more or less highs, with bigger or minor resonance. this is exactly what defines a guitar own very tone.
And here comes the idea:
Now what if you had a pickup with a very small coil? You would have a sign with extended treble response able to reveal string's higher harmonics! This by itself can already be seen as an advantage, the only drawback is that it is necessary to provide gain to the signal, since less induction generates a weaker signal, too. However this just means that you need a preamp close to the PUs and having a built-in pre allows you to control more sophisticated eq circuits right under your fingers.
In Alembic's system, they chose to use low pass filters because, in a way, it allows you to simulate different natural shades of other PU systems, since it allows to lower or raise the cutoff frequency to match the characteristics of other types of PUs and, relying on a variable peak boost, also could emulate the peculiar ressonance peak of other guitars (ie: its PU/Pots/Caps interactions). To be honest, it doesn't look that it sounds like any other guitar, to me they have their own character and nothing compares to it. In fact, we can go far beyond the tone of a normal guitar balancing PU pan, using the Filter with the Q engaged or not and the aid of the bass and treble boost/cut switches (not to mention the Series circuits that gives you even more tone flexibility).
By the way, Alembics are so sensitive that matters a lot the way you use your fingers and where you hit the strings, take some time to get used to it (with fresh strings and a appropriate good amp, because this bass really deserves).
(Message edited by mario farufyno on January 29, 2016)
(Message edited by mario farufyno on January 29, 2016)
