24
Signal path
Your guitar sound passes through the following sections.
Refer to “Top and rear panels” (p. 7) in conjunction with this illustration.
EFFECT
PRE AMP
GAIN
VOLUME
EFFECT
MASTER
POWER LEVEL
PEDAL
MOD/DELAY
REVERB
VALVE REACTOR
VALVE
EL84 (6BQ5)
FX
LOOP
EXTENSION SP
Select one
of 44
What is Valvetronix Pro?
The VOX Valve Reactor circuit is featured in the VOX VT series amplifiers and
ToneLab serieseffects. Although most of the sound processing in these products
occurs in the digital domain, the Valve Reactor power amp is 100% analog.
Passing the guitar signal through the power amp stage as an analog signal is very
important for the feel and tone of the original amp that’s being modeled.
The Valve Reactor circuits of previous models used a 12AX7 vacuum tube (typi-
cally used in the preamp) as their power tube, making it a miniature version of a
tube power amp. In contrast, the circuit newly developed for the VTX150 Neody-
mium uses the EL84 (6BQ5) tube that's actually used as the power tube in amps
such as the VOX AC30, meaning that it will function like a true tube amp. We’ve
named this new technology “Valvetronix Pro.”
The vacuum tube is connected to a power amp circuit that features a special
design in its final output stage. This allows pure tube amp sound to be generated,
while still allowing the user to continuously adjust the power stage’s output
volume across the full range from minimum to maximum output. The wide
dynamic range characteristic of classic tube amps is also maintained. This dy-
namic range is difficult to obtain from solid state amps, and is one of the reasons
that a tube amp sounds more powerful than a solid state amp of equivalent
output wattage. The output of the Valve Reactor power amp “reads” the con-
stantly changing impedance curve of the connected speaker system, and feeds
this information back to the vacuum tube. In response to this information, the
functionality of the amp’s tube stage will vary according to the speaker load
(impedance). This too is an important element in the sound of a true tube amp.
By adjusting these characteristics, every sound of that amp model can be faith-
fully reproduced. This power amp technology, for which a U.S. patent has been
obtained, is unique to the VOX Valvetronix amps.
We trust you will enjoy the Valvetronix Pro sound as newly implemented in the
VTX150 Neodymium.
