Vox AD100VT - Manual (Page 5)

1
S
IGNAL PATH
Your guitar sound passes through the following sections.
(You can refer to “The Guitarist’s Guided Panel Tour” while you read the explanation that
follows.)
V
ALVE
R
EACTOR
T
ECHNOLOGY
T
HE
P
OWER
(
AMP
)
AND THE
G
LORY
!
alve Reactor technology was first used on the VOX AD60VT & AD120VT Val-
vetronix amps.
Since conventional modeling effects for line recording are not used directly with a
speaker, they do not include a power amp circuit, output transformer, or speaker. In other
words, they only have a preamp circuit.
A real valve amp sound, however, is produced not just by the preamp, but also by the tone
and distortion of the power amp, and by the constant changes in impedance that are cre-
ated by the power amp driving the speakers. The AD15VT, AD30VT, AD50VT, AD100VT &
AD100VTH contain an actual low-wattage valve power amp circuit, a virtual output trans-
former (patent applied for) that uses solid-state components to simulate an output trans-
former, and a dummy speaker circuit that simulates the varying impedance of a real
speaker. This means that although it’s low-power, the power amps used in both the
AD15VT, AD30VT, AD50VT, AD100VT & AD100VTH have the same circuit structure of an
actual all-valve (tube) amp.
While much of the tone creation and shaping carried out is done in the digital
domain, the Valve Reactor power amp is 100% analogue. The resulting journey your gui-
tar’s signal takes through the analogue world of the power stage plays a major role in pro-
viding the all-important feel and tone of the original amps we modelled.
The Valve Reactor power stage is, to all intents and purposes, a bona fide valve (tube)
push-pull power amplifier, but in miniature. It utilizes a 12AX7 (ECC83) valve (a dual tri-
ode device — meaning “two valves in one”) and is equipped with an output transformer,
just like a “real” valve amp.
The power amp output signal is designed to “read” the constantly changing impedance
curve of the dummy speaker circuit system and feed this information back to the virtual
output transformer — just like an all valve amplifier does. This information permits the
behavior of the valve stage to vary with the speaker load (impedance), which is another
important part of “real world” valve tone.
Effect
AUTO WAH / COMP
Effect
MODULATION
DELAY / REVERB
Pre Amp model
Choose one of 11 types
Class A
Class AB
Power Amp model
Determined by the
Pre Amp selection
Speaker
Master Vol
V