TM
Quantum
QT 600 Manual
1. The Preamp
1.1 Tube Touch Circuit™
The preamp section plays a pivotal role in the overall design of the
QT600: As interface between bass player and instrument on the one
hand, and power circuitry on the other, it decisively shapes both the
amp's response and the instrument's sonic spectrum. Quantum™
QT600 amps' inputs feature the Tube Touch Circuit™, resistant to
distortion, which guarantees a direct response to the players' touch
and prevents dissonant clipping.
2. Equalizer
2.1 Pure Parallel Technology
Pure Parallel EQ is a technology based on the kind of circuitry
generally found in high-end studio gear. The signal is distributed
to all EQ bands simultaneously rather than being routed through
the bands consecutively. The original signal is routed through via
a passive circuit, practically circling the complete circuit. The filters
for the respective bands arrayed in parallel to this circuit only
process the targeted frequencies, which are then added back to
the original signal.
The Tchebycheff characteristics of the bass and treble filters make
an extremely effectively processed signal possible: neighbouring
frequencies in a selected field are processed in the opposite direction,
i.e. neighbouring frequencies are lowered when a frequency is
boosted, and raised when it is cut. This allows for clearly audible
processing without excessive variations is level.
6
1.2 Connections:
Active
Connect bass guitars with active circuitry to this port. (High output
level, low impedance)
Passive
Connect bass guitars with passive circuitry to this port. (Low output
level, high impedance)
1.3 Gain
The GAIN control determines the input level. But it does more than
just adjust the level – in combination with the MASTER control,
it makes a wide range of nuances between clean- and overdrive-
sounds possible.
1.4 Hot
The HOT indicator provides information about the input level.
But it isn't just a classic control aid – the "magic eye" indicates how
"hot" the preamp is being driven.
1.5 Mute
Mutes the speaker output as well as the DI-Out, LINE-Out and
Headphone -Out. TUNER-Out remains active.
Another special feature is the automatic adaptation of the Q-factor
of the LOW-MID and HIGH MID bell filters. Frequencies are
boosted in a wider band and cut in a narrower band.
Together, these special features make the EQ an easy-to-use sound
tool that guarantees a superior base tone and makes sound-sculpting
and signal correcting possible with just one control. Extreme musical
results that sound "healthy" in any mode are at your fingertips.
The figure shows the sophisticated parallel EQ circuit in comparison
to a simple serial circuit. Note the bands' parallel array and the
passive circuit that carries the original signal.
The figure shows a sophisticated parallel EQ circuit in
comparison to a simple serial circuit. Note the bands'
parallel array and the passive circuit that carries the
original signal.
The figure shows the curves of all EQ bands
and switchable filters.