So . . . . you've got a gain knob next to the strings. The p/u selector runs mute/neck/both/bridge, really cool as you just turn it to mute and put it on the stand, no need to turn it down/off.
The tone control+Q Switch usually takes a little work to grasp (it sure did for me). So here goes:
The tone control actually controls a low-pass filter, not the typical tone pot found on virtually anything else (and all Alembics are like this).
All the way down (full anti-clockwise), everything below 350hz is let thru, everything above is shut out (very little treble, sounds like organ pedals, all mumbling thump and little else). As you turn the tone control to wide open, the 'ceiling' rises to 6khz (REALLY treble-y, lots of finger noise, clavinet-like tone with new roundwounds).
If you visualize a 31-band EQ, Imagine everything from the 6khz slider to the left is at the middle, every thing past it to the right is shoved all the way down. This will help you visualize what's happening.
Then when you kick in the Q Switch, there's a 'bump' that attack-related centered around whatever the tone control is set at. A dynamic related boost, if you will. Imagine that same 31-band EQ, bump that same 6k slider UP 8db, and the slider on either side of it about half of that, and you can visualize the Q function.
French enough?
Now I've owned a Spoiler 5 with exactly this layout for over 10 years. Living and playing it in real life, this is what I've found:
The Q-Switch reaction really is related to how you play. I'm basically an old-school fingerstyle player, so in that case, I don't hear much of a difference, Now when I play hard with a pick, I do hear a 'snarkier' more aggressive edge to the tone. It's seamless, you don't hear any sort of gate, it just gets that much more brighter, depending where the tone is set.
An instant Chris Suire tone can be had by running neck pickup only, Q on, and pick hard back towards the bridge. Instant 'Roundabout' tone, though more hifi than those old Rics.
As the pickups are at the end of the fingerboard and butted up against the bridge, there's a big difference in tone between the two.
While we're at it, do you know about the mixer in the control cavity for setting your relative gains?
But essentially you can go from organ pedal density to clavinet-like tone in about half a second, really amazing with just two knobs and two switches !
J o e y