Quantum QT600 - Manual (Page 8)

4. Power Amp
4.1 Dynavalve™ Technology
Dynavalve™ is a new, patented technology. Just like in classic
tube circuitry, the phase-splitter tubes and speaker feedback work
together to “force” the power transistors to act just like amp tubes.
The dynamics, overtone spectrum, and even the impedance
matching to the speakers works exactly like in a tube amp.
The result: better tone, more sound pressure, greater punch!
Note:
All special Quantum™ PRO speakers have integrated HF systems.
The dual cone (10“) or DuraDome™ (15“) design yields a homoge-
nous, wide overtone spectrum without the bundling and phasing
errors that typically arise with HF-horns.
3. Tube Growl
3.1 Tube saturation & compression
Tube Growl is a complex circuit that controls peaks like a tube
preamp does, converting the energy of spikes into overtones rather
than allowing it to dissipate. Not only the fundamental frequency
sounds as though it were generated by a string, but so do the
harmonic overtones, i.e. the frequency generated by the half string,
third, quarter, and so forth.
The relative levels of harmonic overtones are decisive in shaping
tone, so it takes the right mix to yield a warm, punchy sound.
An intelligent compressor controls the tube saturation and prevents
excessive distortion. String attack stays up front – there is no masking
of attack, no pumping sounds, no sonic side effect. Rather, there is
a singing sustain and a punchy sound that’s fun to play.
3.2 Tube Growl
The TUBE GROWL knob, which allows you to dial in natural
compression and tube effects, is a particularly handy feature. It puts
the ability to control the compressor parameters – threshold, ratio,
make-up gain, attach and release – as well as tube saturation levels
at your fingertips.
3.3 Fat
The FAT indicator provides information about the level of tube
saturation. The brighter the “magic eye,” the more powerful the
TUBE GROWL effect.
Quantum
TM
QT 600 Manual
Solid state power amp without
speakers connected Solid state power amp with
speaker connected
Tube power amp without
speakers connected Tube power amp with
speaker connected
DynaValve™ power amp without
speakers connected DynaValve™ power amp with
speaker connected
The figure shows the harmonic overtone
spectrum generated for a fundamental tone
of 500 Hz.
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