Vox AD100VT Musical Instrument Amplifier User Manual


 
18
TUBE TALK
Us Brits call ’em valves while our US cousins call ’em tubes ... as the saying goes:
England and America are merely two countries divided by a common language! Anyway,
call ’em what you will, these wondrous glass bottles lie at the tonal heart of each of our
11 models. As all the amps we’ve modeled hail from one of the two countries just men-
tioned, in honor of their heritage, the descriptions of all English amps will employ the
words “valve” and “valves,” while the American ones will be tubular!
POWER AMP ACCURACY
As already touched on a couple of times, what happens in the power stage of any good
tube amp is of paramount importance to the way the amp sounds, feels and behaves.
The way the power amp operates (Class A or Class AB), the power tubes used
(EL84s,EL34s, 6L6s, 6V6s), the exact nature of the negative feedback loop circuitry, and
how the power stage interacts (a relationship called damping) with the speaker(s) it is
driving — all these things play a vital role in the creation of tone. And, thanks to our pat-
ented in USA Valve Reactor Technology all these important bases are faithfully and accu-
rately covered. For example: if you choose the amp model AC30TB — an amp with a
Class A power stage and no negative feedback — that’s exactly what your Valve Reactor
power amp reconfigures itself to emulate. And, as an added bonus, thanks to our rear
panel POWER LEVEL control you can adjust the output power (Wattage) to best suit the
size of the room you’re playing in. (The AD15VT doesn’t have this feature.)
TURN IT UP!
Truly great, all-valve amps have one thing in common — they invariably sound at their
best when they’re cranked to the max! It’s got nothing to do with eardrum shattering deci-
bels either; it’s just that when the power valves are driven hard, they definitely impart a
unique tone and width to the overall sound. Thanks to the awesome accuracy of our
Valve Reactor power amp, the same is also true of your Valvetronix combo. For this rea-
son, we heartily recommend that you crank the sucker up as often as possible. And, as
already pointed out, thanks to our unique POWER LEVEL control (not provided on the
AD15VT), you can adjust the output Wattage to suit every occasion — from bedroom, to
garage, to gig ... and all points in-between. So, what are you waiting for — select, crank
‘and’ enjoy!
This all said, let’s take a look at each of our amp models...
QUESTION: What’s the difference between an ECC83 preamp
valve and a 12AX7 preamp tube?
ANSWER: Nothing! They’re the same exact thing — namely the
most popular preamp tube in ampland. ECC83 is the British name,
12AX7 (a.k.a. 7025) is the American.