pg_0001

Bulletin 0407

Product Overview

The Spectral

DMC-30SS Studio

Standard Preamplifier

infrastructure with a new 'clear sheet' systemboard

design. The result is a fresh interpretation of the

elegant DMC-30 topology implemented with the most

uncompromising new power supplies, circuit layout

and control elements ever used in an audio preamp.

The New Floating Power System

Music and theater systems are becoming larger and

more complex so that stray interferences from other

components and environmental sources must be pre-

vented from entering and contaminating sensitive audio

signals. A common path occurs from power cords that

transmit noise residue and harmonics from large amp-

lifiers, video equipment and other components. Higher

frequency digital noise may propagate through signal

cables to add further sonic loss. The 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

and audio/video sources. Its combination of dense

physical size and electrically open circuit character,

out performs batteries and other devices to provide

very pure floating power. Amplifier circuits within the

DMC-30SS receive highly regulated voltages as if

from small batteries. But unlike batteries, the floating

shunt regulator isolates both low and high frequency

noise contamination so circuits are neither subject to

outside noise, nor pass residue from amplification of

contaminated audio signals. This environmental isol-

ation improves performance from complex sound sys-

tems as well as assures unhindered performance from

the DMC-30SS itself.

The Spectral 'Floating Power' regulator is a superior

approach to noise isolation. While some interferences

can be blocked by various AC line isolation products,

their use is often problematic with unpredictable sonic

side effects and additive distortions. Spectral 'Floating

Spectral Audio is a company which was founded on

research in high-end preamplifier design and our

depth of commitment to the importance of this work

runs deep. For this reason, engineering priority has

always been placed on development of the most adv-

anced reference preamplifiers possible. The DMC-30

series has occupied a special place among Spectral

reference preamps, moving the state-of-the-art steadi-

ly forward with a constant evolution of performance

innovation and refinement. Now Spectral introduces

a new reference preamplifier for the most demanding

musical application, the DMC-30SS Studio Standard.

The DMC-30SS Studio Standard combines new tech-

nology advances from state-of-the-art recording with

extreme precision componentry and micro-detailed

layout to again redefine the art of preamplifier design.

In previous DMC-30 generations, emphasis on active

amplifier development has resulted in major advances

in line section refinement, culminating in the unparal-

leled performance of the SHHA high-speed output

modules. Due to the over-capacity and robust design

of the original DMC-30, this unstressed platform has

required very little improvement to support ever

evolving performance in this area. In the DMC-30SS,

Spectral engineers return to basic issues of foundation

Spectral Audio, Inc.

442 Oakmead Parkway

Sunnyvale, California 94085

408.738.8521 Fax: 408.738.8524

COMMITMENT TO EXCELLENCE IN MUSIC REPRODUCTION

Power' is an integrated system for noise suppression

which outperforms external AC line conditioning

products which impose their own sonic colorations.

The Case for Uncompromising Attenuation

Certain devices in a high-end preamplifier fundament-

ally 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 of these approaches

have serious compromises which limit signal transpar-

ency, 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. Spectral engineers have long experi-

ence researching digital and DAC attenuators and

find that none of these gain controls are really up to

the demands of high-end preamp use, let alone for

critical recording applications. We find the best relay

and switch based resistor attenuators to be much better

sonically than any digital control. Unfortunately, they

in turn suffer from dynamic range and contact life

limitations, more importantly they are not a realistic

option when continuous gain adjustment is required.

Since digital attenuators are not sonically transparent

and stepped resistor attenuator controls have step size,

contact life and dynamic range limitation, the ultimate

gain control would have to be a continuously variable

potentiometer or fader. Unfortunately, no pot or fader

currently available is transparent or linear enough for

the most critical gain adjustment applications in audio.

Spectral Develops the Super Fader Technology

To solve the problems of existing gain control systems

Spectral engineers have been working with a leading

aerospace contractor. Out of this multi-year 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 preci-

sion machined from solid precious metals. These

wipers have many surfaces that are spring pressured

as a group to contact micro-polished optically flat

resistance elements. Exemplary mechanical design

and fabrication alignment is used to prevent localized

heating from circulating currents. Ultra-pure contact

metal eliminates solid-state or junction distortions

which occur from plated parts used in other controls.

When such precision and material commitments are

combined, noise and error in the presence of test sig-

nals is immeasurable and other performances are very

near to ideal thermal accuracy limits. With polished

custom element and ball-bearing construction, there is

every indication that this superior performance will

remain intact even after 100 million operations. The

'Super Fader' potentiometer outperforms all existing

gain control systems with virtually infinite service

life. We hear a clarity and transparency, as if a wire

has been substituted for the control.

The Spectral DMC-30SS Studio Standard

Spectral founders are deeply committed to high-end

audio design in a most uncompromising way. In a

world of relativism and compromise we believe that

highly accurate reproduction most fully honors fine

recorded performances as well as being profoundly

musical. The DMC-30 Studio Standard Preamplifier is

our most advanced expression of this ideal. Exhaust-

ive testing under live recording conditions has created

a true reference. With virtually no coloration or char-

acter of its own, the DMC-30SS is an extraordinarily

transparent and truthful window on great music.

The DMC-30SS is for the serious music enthusiast

who is a patient and sophisticated listener. We hope

you will take an evening to experience the new DMC-

30SS. We think you will discover a new world of

expressiveness and life in all your favorite recordings.

Bulletin 0407

COMMITMENT TO EXCELLENCE IN MUSIC REPRODUCTION