On the occasion of our twenty-fifth anniversary Spectral released a special reference preamplifier design for serious music enthusiasts. The DMC-30SL commemorates twenty-five years of state-of-the-art preamp design at Spectral beginning with the company’s first revolutionary products which were introduced in the mid 1970’s. The DMC-30SL has again redefined the art of preamplifier design with a comprehensive array of engineering breakthroughs which set new sonic standards and raise the bar on signal accuracy in the most demanding systems. Now Spectral introduces the DMC-15 Studio Reference Preamplifier based on the engineering refinements developed for the DMC-30SL anniversary reference preamplifier. The new DMC-15 encompasses the innovative signal advances pioneered in the DMC-30SL to combine state-of-art performance with exceptional value. The Essential Audio Component It has been fashionable in some audio marketing to promote the elimination of the audio preamplifier as a purist approach to better sound quality. In reality, this simplistic approach is easily discredited with careful listening and hardly debatable when it comes to quality music systems. By no stretch of the imagination have today’s best source components been designed to assume the complex role performed by a high-performance preamplifier. The responsibility for impedance matching, gain optimization, filtering, and signal buffering are only some the essential functions performed by the preamplifier. Just as these duties cannot be ignored, their performance must be accomplished with extreme signal purity. Unlike variables occurring further down the component chain, differences in preamp quality have a major effect on final system sonics. Since preamplifier performance is overwhelmingly important to realize the absolute best possible sonic results in quality music systems, the DMC-15 was developed to meet the very highest standards. Rather than employ more conventional design and circuitry for our more affordable preamplifier such as usually practiced by high-end designers, Spectral engineers have instead looked to the acclaimed DMC-30SL ‘anniversary’ reference preamplifier for the essential design and topologies of the new DMC-15. More specifically, the DMC-15 has been directly derived from the exotic DMC-30SL layout and circuitry as a ‘straight-line’ version of the reference preamp. The resulting DMC-15 is actually a single-ended version of the DMC-30SL with manual attenuation and controls. Not surprisingly, signal resolution and linearity are virtually without compromise in the DMC-15 since all amplification and layout architecture are shared with our top edge-of-the-art reference preamp design. Honoring the Music In the manner of all Spectral components, the DMC-15 presents a functional, elegant face to the world, one devoid of complication or undue decoration. Impressions of design simplicity and balance extend to the interior of the DMC-15 with its immaculate board layouts and instrumentation quality components. As straightforward and elemental as it might appear, the DMC-15 layout design is deceptively sophisticated requiring many development generations and hundreds of painstaking tuning hours to arrive at ultimate sonics and circuit refinement. Few audio products are destined to receive the level of close scrutiny and circuit detailing lavished on the DMC-15 during its development period. To achieve this ultimate circuit performance, Spectral engineers employ our exclusive ‘micro-detailing’ design techniques. ‘Micro-detailing’ analysis looks deep into circuit behavior, selecting best possible layout and tuning combinations to reduce subtle noise and distortion phenomenon in complex signal material. Sensitive circuit characteristics such as minimizing energy storage for rapid signal extinction are rigorously pursued. Over the years we have found these critical circuit details are essential for the most neutral and transparent sonic behavior. The ultimate preamplifier, after all, must be an accurate reproducer and not a musical instrument in its own right, no matter how seductive it might tend to make a certain recording sound. New SHHA Technology Once every decade or so Spectral engineers assess our fundamental amplification topologies in light of the ongoing evolution in high-tech analogue practices and premium discrete component technologies. Since the development of ultra high quality analogue circuitry is an evolutionary as opposed to a revolutionary process, fine analogue circuitry born of care and thoughtful refinement tend to work and sound best, even if they were not designed just yesterday. Spectral’s most recent reevaluation of our fundamental amplifier topologies occurred in the late 1980’s resulting in some of the most highly regarded analogue and digital audio components in the industry. Now Spectral introduces a new implementation of our ambitious discrete analog signal technology in the form of an ultra high-performance gain cell for preamplifiers like the DMC-15. The new SHHA Module (Spectral High-speed Hybrid Amplifier) takes Spectral’s wideband, fast-settling discrete circuit topology to a new level of performance and signal linearity. Using newly available premium discrete component technologies, Spectral engineers have developed a dense, highly optimized surface mount topology for higher signal speed and ultra-fast signal extinction. Reduced size of the new all fet topology results in improved cross-coupling and noise isolation for ultra quiet operation. Even more remarkable given the compact layout of the SHHA module is the exceptional nature of its power capabilities. The SHHA module is a high-current powerhouse producing full output at 1 MHz and one full ampere, setting new standards for headroom and drive capability in a preamplifier line section. The Affordable Reference Preamplifier Our goal in the DMC-15 Reference Preamplifier is to bring the performance advantages of our advanced DMC-30SL preamplifier technology to a wider audience of music enthusiasts. By omitting non-essential features such as remote operation and balanced output, design priority can be directed toward highest possible performance rather than accepting traditional compromises between sound quality and price. The DMC-15 design focuses resources directly into premium circuitry and component quality rather than into additional convenience features. The result is sonic precision unprecedented at such a reasonable price uncompromised by the quality and performance tradeoffs normally associated with other competitive high-end preamplifier designs. Now more music lovers can experience the unique sense of life and ‘you are there’ realism that a state-of-the-art Spectral preamplifier can offer as the heart of a fine music system.