Briefly, the controls are Volume, Pan, Low Pass Filters for each pickup, and a "Q" switch for each filter.
As you turn the low pass filters clockwise, they allow more of the higher frequencies through the filter. Think wah-wah pedal.
The "Q" switch adds a boost of about 8db or so to the cut off frequency you selected by the filter position.
For example, pan full to the neck pickup, turn the filter fully counter clockwise and play a note. Then hit the "Q" switch and play another note. You should hear a boost in the bass frequencies. Now fully open the filter and repeat. You hear the boost in the higher frequencies the "Q" switch produces from the higher cutoff point.
One sound I like is a fully closed filter with "Q" switch on for the bass pickup, and bringing in the higher frequencies with just the treble pickup. Lots of tones to find.
And if you find the standard 2 position "Q" switch boost too much, Alembic offers a 3 position "Q" switch with a nice medium boost in the middle.
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