It required years
of painstaking research and
development and exhaustive listening
trials to create the renouned
DMC-30SV 'Super Veloce' Reference
Preamplifier. The DMC-30SV succeeds
the classic DMC-30SS reference
preamplifier, for eight years our
most popular product and one of the
most highly regarded audio
components in the high-end audio
industry. Developed over the course
of three years, the DMC-30SV is the
fourth generation of the DMC-30
family which music enthusiasts
worldwide have come to regard as the
gold standard in state-of-the-art
performance and top value. The
DMC-30SV utilizes new Spectral
exclusive technologies and
componentry to raise the bar in
signal control and amplification to
a new level of precision. With the
stunning success of the DMC-30SV
reference preamplifier, Spectral
customers have clamored for a
simplified preamplifier utilising
the new SV technology. To meet this
challenge, Spectral engineers have
devised a new 'straight-line' DMC-30
which utilizes single-ended
operation for inputs and outputs.
This single-ended DMC-30 is called
the DMC-30SC. It offers the singular
performance of the benchmark
DMC-30SV in a new ultra high-value
preamplifier. Since the
establishment of our company in the
1970s ~d the introduction of our
very first audio component, high
performance preamplifier design has
occupied the highest engineering
priority at Spectral. Our special
focus on high-end preamplifier
development over the years is based
on the major design challenges which
low-level amplifier and control
circuitry can represent. At these
critical signal levels minute
amplifier distortions and signal
control colorations are passed on
and magnified by power amplifiers to
dominate the sonic signature of the
best audio systems. Spectral
engineers have spent the last four
decades pursuing ideal performance
and signal transparency in audio
preamplifiers to realize ultimate
fidelity in high-end music systems.
The Super
Veloce Technology
In the DMC-30SV and DMC-30SC
preamplifiers our engineer have
evolve the renowned DMC-30 topology
with our most advanced amplification
circuits to date. Utilizing recent
breakthrough understanding in
highspeed transistor behavior, new
semiconductor designs exclusive to
Spectral address historic
limitations in amplifier linearity
and banish low-level distortions to
previously unattainable levels.
These devices are utilized in our
new generation high-speed, wide-band
preamp output sections with
unprecedented results.
Thermal Memory and Super
Transistors
For years Spectral engineers
have investigated the fleeting
signal memory distortions found in
certain semiconductor devices known
as "thermal tails". These elusive
non-linearities occur at high speeds
in transistors during switching as
junction behavior changes as a
function of heating and cooling.
This change in semiconductor
switching behavior affects amplifier
circuit linearity until the device
recovers from transient heating.
This "thermal memory" distortion has
long been a recognized phenomena in
high tech amplifiers circuits for RF
and microwave but is ignored by
conventional audio engineers. In
high resolution audio amplifiers,
however, we fmd low-level transistor
distortions problematic as they
compromise signal linearity and
transient settling. Having isolated
and observed these distortions in
our own high-level driver circuits,
Spectral engineers first addressed
their elimination in our reference
standard amplifier designs. Solving
these subtle distortions which blur
transient waveforms requires
uniquely precise test and
measurement systems and specific
semiconductor designs which do not
change their linearity under
transient signal conditions. The
results of this development are the
finest performing amplifier circuits
we have designed. Now our goal in
Spectral preamps is to successfully
apply the benefits of the new
semiconductor technology for the
first time. The
SHHA Generation 3 Analog Line
Modules
Just as the preamplifier is the
essential heart of the finest music
systems, the 'Spectral High-speed
Hybrid Amplifier line module is the
essential heart of our high
resolution preamplifiers. For this
reason, the modular architecture of
Spectral preamps has been developed
to accommodate the design evolution
of our SHHA technology with
convenience and ease. Now the new
SHHA G3 line module takes our
wideband, fast-settling discrete
circuitry to a new level of
refinement and signal resolution.
Spectral engineers have continued to
optimize the dense surface-mount Fet
topology of the SHHA module with new
ultra premium custom semiconductor
devices and new circuit innovation
and refinement.
The input cascade of the SHHA G3
module utilizes our own proprietary
Fet technology. These new dual J-Fet
devices developed for Spectral,
provide higher gain with ultra-fast
transient settling. In addition,
Teflon SMT precision film capacitors
provide ultimate signal transparency
in critical circuit locations.
Custom ultra low value polystyrene
film capacitors and Teflon film
trimmers adjust each module for
ideal transient responce and
wideband stability. These and other
advances in the SHHA G3 module
assure uncompromising sonics and
extended reliability. Musical
results include Vastly improved
imaging and focus have resulted from
the elimination of these transistor
thermal-tail distortions. THe Case
for Uncompromising Attenuation
Certain devices in a high-end
preamplifier fundamentally determine
the ultimate performance possible in
the component. Since a preamplifier
basically amounts to an adjustable
line amplifier, the role of the
volume control or gain attenuator
system is especially critical and
will have a strong influence over
the final sonics of the component.
Most of today's high-end preamps
incorporate various digital and IC
based attenuator systems to control
gain, while a minority still use
mechanical controls, potentiometers,
switches or relay arrays. In our
experience, all these approaches
have serious compromises which limit
signal transparency, dynamic range,
step resolution or reliability.
Today, digital based IC attenuators
are ubiquitous in modern audio
design. But even the most exotic of
these digital and solid-state
attenuators color the sound in
various ways. Since digital
attenuators are not sonically
transparent and stepped resistor
attenuators have step size, contact
life and dynamic range limitations,
the ultimate gain control would have
to be a variable potentiometer or
fader. Unforrunately, no pot or
fader currently available is
transparent or linear enough for the
most critical gain adjustment
applications in audio. higher
resolution, greater dynamics and
improved. The
Spectral Super Fader Technology
To solve the problems of
existing gain control systems
Spectral engineers work with a
leading aerospace contractor. Out of
a multi-year design effort comes an
extraordinary ultra-precision gain
control. The Spectral 'Super Fader'
combines mechanical precision,
advanced materials science and
unrestricted use of exotic materials
to create a level control that
behaves like an infinite number of
theoretically ideal resistors.
Inside, the critical moving parts
are precision machined from solid
precious metals. These wipers have
many surfaces that contact
micro-polished optically flat
resistance elements. Exemplary
mechanical design and alignment is
used to prevent localized heating
from circulating currents.
Ultra-pure cont.act metal eliminates
solid-state or junction distortions
which occur from plated parts in
other controls. When such precision
and material commitment are combined,
noise and error is unmeasurable and
performance is very near to ideal
thermal accuracy limits. The 'Super
Fader' potentiometer outpreforms all
existing gain control systems with
virtually infinite service life. We
hear a transparency, as if a wire
has been substituted for the control.
The DMC-30 Floating Power System
Key to the performance of the
DMC-30 is a most advanced powering
system and regulator topology
we call the 'Floating Power' system.
It offers extreme isolation from
environment.al and ac line
interferences while powering
sensitive signal circuits in a
remarkable silient envelope. This
floating power or battery-like
regulator was developed for the
SDR-4000 Reference CD Processor and
it has demonstrated a superior
isolation of noises that occur from
power line, audio/video and digital
switching sources. Its combination
of dense physical size and
electrically open circuit design,
can out perform batteries and other
devices to provide pure floating
power. Amplifier circuits within the
DMC-30 receive highly regulated
voltages as if from many small
batteries. But unlike batteries, the
floating shunt regulator isolates
both low and high frequency noise
contamination so circuits are not
subject to outside noise, nor pass
residue from amplification of audio
signals. This enviromental isolation
improves performance from complex
sound systems as well as assuring
unhlndered perfrmance from the
DMC-30 itself. The Spectrtal
'Floating Power" regulator is a
superior approach to powering and
noise isolation. By integrating
supply regulation with noise
supresion it outperforms ac line
isolation products which impose
their own colorations.
The DMC-30SC Reference
PreamplifierUncompromising
Performance and Value
We are pleased to see more and
more music enthusiasts are coming to
understand that no music system can
be any better than the performance
of its preamplifier. There is
growing sophistication in regards to
absolute performance and price. At a
time when ultra high price
preamplifiers are routinely
introduced at several times the cost
of Spectral, the thoughtful music
enthusiast is left to wonder exactly
what benefits these lofty prices
bring? We believe the sohisticated
customer will find the answer in the
uncompromising DMC-30SC. Few
preamplifiers at any price can boast
the designer credentials and
unrivaled component quality of the
DMC-30SC. Edge-of-the-art amplifier
technology and advanced custom
component design are utilized
throughout the DMC-30SC to a degree
rarely seen in stratospheric
components. This is because Spectral
engineers have identified those key
components that most determine
instrument stability and sonic
transparency and have invested
agressively. When careful investment
in superior circuit performance and
signal path components becomes the
design priority over elaborate
metalwork sculpture,
state-of-the-art clarity and signal
resolution can be achieved with
affordably and and high value. The
world renouned Spectral DMC-30SV has
redefined preamplifier performance
and signal resolution in the most
ambitious music systems. Now the
DMC-30SC reference
preamplifier offers enthusiasts the
advanced 'Super Veloce' amplifier
technology introduced in the
DMC-30SV in a remarkably affordable
single-ended DMC-30 design. The
stunning clarity of DMC-30
preamplifiers is not achieved by
accident but was accomplished
through painstaking engineering and
listening care based on our forty
years of preamplifier design
experience. The DMC-30SC brings the
breakthrough performance and
instrumentation quality of the
DMC-30 family to a wider audience,
offering a new level of musical
realism and exceptional value
previously unknown in the audio
industry. Compare our new DMC-30SC
reference preamplifier against the
most costly and ambitious highend
preamps. We are confident you will
discover the important musical
difference Spectral's superior
engineering and design innovation
can make in your listening
experience.
Features
- Full feature
remote control operates all
functions.
- Indicator
displays are clearly visible
from a distance.
- New
generation high-level line
output section topology.
- Improved SHHA
G3 ultra high-speed hybrid
amplifier modules with ultra
precision compensation
components.
- 80 volts
peak-to-peak output voltage for
unprecedented dynamics.
- Relays allow
signal control selection at the
optimal point in the circuitry,
maintaining the
shortest signal
path.
- Microprocessor "sleep mode" and
silent display architecture.
- Cost-no-object disaete custom
component technologies.
- Custom
ultra-precision mil-spec studio
audio attenuator.
- Ultra
low-noise "silient power" supply
system, with floating ground
shunt regulation.
- Three-tiered
architecture takes the signal
path off the power supply
circuit board.
- Fully
symetrical architecture takes
maximum advantage of
differential operation.
- Optically
isolated protection systems for
maximum signal purity.
- Optional
balanced input and balanced
output modules. Specifications
- Input
Compliment: 7 Inputs - 5 normal,
t balanced (optional), tape
monitor
- Output
Compliment: 3 outputs - normal,
balanced (optional) , tape
- Output
Attenuation: Motorized custom
fader conductive plastic,
modified log taper
- Output
Balance: Relay attenuator system
with center position bypass
- Mute Switch:
0, -20 dB attenuation
- High Level
Trim: 0 and -12 dB attenuation
for all high level inputs
- Mode
Switches: Stereo/Mono, Absolute Phase
- Input Select:
6 position, and tape monitor
- Output Level
Display: 50 step LED
- Output Balance Display: 5O
step LED
- Input Impedance: 15Kohms
- Output Impedance: 100ohms
- Gain: 20 db unbalanced, 26db
balanced
- Input Impedance: 11 K ohms, t
00 ohms minimum load
- Output Impedance: 2Kohms
- Protection Mode: DC offset,
oscillation
- Method: Crowbar output relays
- Sensitivity: 20 mV continuous
DC
- Recovery: Approximately 10
seconds
- Chassis Temperature: Internal
48° C @ 25 ° C room temperature
- Frequency Response: DC to 5
MHz, -3 dB, DC to 1 MHz, -.10dB, Any
level to 36 V RMS
- Slew Rate: 1000 V/us or
greater
- Rise Time: 70ns
- Distortion: Less than .005 "lo
THO and IM
- Crosstalk: Greater than 92 dB
- Noise: 105 dB A Weighted, ref
100 mV@ 1 KHz
- Output Voltage: 1.6 VRMS, 100
V peak to peak maximum
- Output Current: 1 Amp maximum
per channel, balanced out
- Remote Control: Operates all
front panel functions, level and
balanee rates, display brightness,
and system reset
- Dimensions: 48.3 cm (19") W,
10.4 cm (4.1 ") H, 31.1 cm (12 .25")
D
- Weight: 11.8 kg (26 lbs) net.
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