Mephisto Solo Mono Power Amplifier
|家庭影院技術 (Home Theater Tech) Vol.269|
They said it couldn’t be done. Or maybe they just meant that it shouldn’t be done in a prevailing climate of global financial meltdown. In either case, anyone even remotely familiar with the workings of the mind of Gryphon founder and CEO Flemming E. Rasmussen knows that this is exactly the kind of challenge on which he thrives.
While other High End manufacturers are quietly closing up shop or reluctantly downsizing their ambitions in concession to an increasingly gadgetised and commodified audio market, Gryphon Audio Designs boldly and proudly offers the world the most advanced and, yes, most costly amplification components in the brand’s history.
The Pandora preamplifier and Mephisto stereo power amplifier bravely bucked current trends of austerity and restraint, opening up new dimensions in home entertainment for the serious music lover. Designed and built for the select few who can appreciate and afford this level of uncompromising musicality, the Pandora/Mephisto system announced to the world in no uncertain terms that Gryphon continues to stand by the commitment to ultimate fidelity in home audio that is the foundation of the company’s worldwide reputation.
The Next Step?
Of course, being Gryphon aficionados and, therefore, by definition, connoisseurs of the finer things in life, Gryphon owners immediately began speculating about what the next step might be for Rasmussen and his adventurous band of engineers and audiophiles. Nothing exceeds like excess, as an old saying goes.
Now, for the most demanding among the fortunate few who make up the Gryphon audience, for that limited circle able and willing to travel with us all the way on our journey, Gryphon presents the Gryphon Mephisto Solo single-channel power amplifier.
While monoblock construction is not unheard of in the High End, most often manufacturers take the easy way out, by simply creating a bridged version of an existing two-channel product. Bridging couples the stereo channels in series to form a single amplifier with increased voltage and, nominally, more output power. Unfortunately, the inevitable side effects of this approach include doubling distortion, doubling the input impedance (impairing the amplifier’s ability to drive low-impedance loudspeaker loads) and cutting damping factor in half (reducing the amplifier’s control of cone motion at low frequencies).
The Gryphon Mephisto Solo elegantly eliminates these issues by running two stereo channels in parallel (not in series) for unchanged output and voltage, but double the current and half the distortion. As always, extreme high current capability is a fundamental parameter in Gryphon amplifier design. Capable of massive current swings, Gryphon Mephisto Solo maintains the dynamic integrity of the audio signal even under the most extreme reactive loudspeaker load conditions. The extraordinary load tolerance of the Mephisto Solo means that it will bring out the best in any loudspeaker.
Mephisto Stereo Mono Power Amplifier
Since it is the function of a power amplifier to modulate the mains current from the wall socket, the presence of even miniscule amounts of noise in the mains voltage can prevent a system from living up to its ultimate potential.
The carefully regulated and filtered power supply of the Gryphon Mephisto removes harmful high-frequency noise and voltage spikes without compromising current capacity. The complete removal of mains noise enhances focus, immediacy, transient crispness and soundstage depth for a more beguiling and engaging listening experience.
Zero Global Negative Feedback
While negative feedback is a widespread means of suppressing measurable static forms of amplifier distortion, copious amounts of feedback have the unfortunate side effect of introducing an over-damped, sterile sound, because the feedback itself leads to a rise in audible, dynamic distortion.
Gryphon Mephisto is designed with zero global negative feedback in order to meet the dynamic demands of the very best analogue and digital source components. The exceptional bandwidth of the Gryphon Mephisto – beyond 350 kHz – is achieved despite the total elimination of feedback.
Extreme Attention to Detail
Each printed circuit board in the Gryphon Mephisto is designed to facilitate accurate assembly and precision mounting to set a new standard for mechanical and electrical stability. Ideal constant safe operating conditions for all transistors in all amplifier stages maintain consistent performance, regardless of variations in temperature or signal level.
Only the finest components are employed throughout for optimal electrical and audio characteristics, including Takman resistors from Japan, Class A dual J-FET transistors in the input buffer for speed and clarity, a balanced differential input circuit based on a single carefully selected dual bipolar junction transistor. The voltage amplification stage incorporates high-speed Zetex surface mount transistors with minimal capacitance and high DC current gain (Hfe) and the output stage employs high-speed Toshiba pre-driver transistors.
A fully symmetrical, regulated low noise voltage supply has been used for all voltage amplification sections. Eight 56,000 microFarad capacitors with low ESR (Equivalent Series Resistance) for a total capacity of 448,000 microFarad/100V smoothes the voltage to the output supply. Static shielding isolates primary and secondary windings in the massive dual Holmgren transformers designed and built especially for the Gryphon Mephisto.
By eliminating output relays, Gryphon Mephisto achieves an extraordinary low output impedance. But most importantly, because output relays that can handle huge constant currents tend to have poor low to moderate signal transfer characteristics, the best relay is quite simply no relay at all. As always with Gryphon, what is left out is just as critical as what goes in.