The Greek letter Σ (Sigma), used in mathematics, science and engineering to indicate summation, provides a fitting moniker for Classé’s newest series of high-end preamp/processor and amplifiers. High-end is about passion, discovery, experience and technical exploration – it is the sum of all of these things, reflected in the products themselves and shared by those fortunate enough to own them.
All Classé components are designed to meet demanding technical, quality and objective standards and by their nature, they are costly. In some cases they are also large—perhaps even too large for a given application. For some time now there has been an unmet need for audio components that meet the high standards of Classé Delta and CT series designs but are more affordable, smaller and more efficient. The Classé Design team has brought its wealth of knowledge and experience to bear on the problem with the result being the Sigma series.
The Sigma series amplifiers AMP2 and AMP5 feature the latest switching technologies, first used in the Delta series CA-D200. Just as the Classé Delta and CT series class A/B amplifiers share the same internal circuitry but use different chassis to accommodate specific applications, so too does the AMP2 share the same circuitry as the CA-D200. The AMP5 shares the same overall topology as the stereo model, but with the necessary changes to implement its five-channel design. Switching technologies are utilized in both the power supply and amplifier stages of the AMP2 and AMP5 to achieve greater overall performance, efficiency and smaller size than alternative solutions.
Surround Sound Processor (SSP)
The Classé Sigma SSP Surround Sound Processor is the result of a singular focus on sound quality. While it is comparatively feature-rich, the design approach in no way compromises performance. In fact, no other SSP boasts such a high performance/ price ratio with as many useful features dedicated to optimizing performance. By eschewing the typical list of marginal extras, Classé has created the Sigma SSP, a multichannel preamp/processor that simply has no peer.
The Sigma SSP is descended from a long and distinguished line of Classé SSPs. Every effort has been made to retain the performance expected of an SSP at double its price, while introducing new features and enhancing its flexibility as a combination music and theatre system component.
New features include Ethernet connectivity with proprietary signal clocking for streaming DLNA sources and AirPlay, as well as IP control from Apple iOS devices using a Classé App; a proprietary 24-bit/192 kHz Asynchronous USB path with both Host and Device connections; front panel HDMI and Headphone connectors and an optional internal MM/MC phono preamp module.
A highly refined nine-band parametric EQ is available for each channel to help tame unwanted speaker/room interactions. Classé’s customizable digital domain Tone Control can be used in Tilt mode to quickly and easily make subtle tweaks to the tonal balance of recordings without making sonic trade-offs. A new and powerful Texas Instruments DSP decodes the full suite of HD Audio signals and handles a wide range of processing tasks including Dolby Volume. The Sigma SSP is indeed comparatively feature-rich, but performance-oriented features dominate its otherwise minimalist design.
At only two rack spaces high the Sigma SSP packs a lot of performance and flexibility into a relatively small chassis. There are eight output channels which, to optimize stereo performance to the fullest, include true balanced connections for the front Left and Right channels. These channels also benefit from a differential D/A converter configuration, using the same D-to-A converters as the venerable CP-800 and providing high resolution with common mode rejection of noise and distortion. Two Auxiliary channels may be configured as Rear channels, Height channels, mirrors of
the front L&R for power-bi-amping, down- mixed fixed- or variable-output for routing the source to another system, or one may be used for a back channel.
The Sigma SSP offers the essential connectivity and functionality of a surround sound processor with modular video and DSP boards, while attaining the highest performance possible at its price. By devoting the design budget to the signal paths you use the most, it tops the list of well engineered, high-value, high-end multichannel preamp/processors available today.