Gryphon Mephisto Stereo Power Amplifier
Description
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.
Isolating power amplifier channels in completely independent enclosures offers additional crucial advantages. With separate power supplies, rectifiers, regulation, preamp stages and gain stages, there is no interaction whatsoever between channels. What happens in one channel at any given time (for instance, extreme instantaneous dynamic demands) is entirely independent of and therefore unaffected by anything going on in the other channel.
Total physical separation of the channels eliminates any possibility of inter-channel crosstalk, providing infinite stereo separation.
As a result, the Gryphon Mephisto Solo drives loudspeakers with greater ease, control and authority, delivering a more spacious soundstage in all dimensions, rich detail against a silent background and tighter, more extended bass. Less critically, independent mono amplifiers offer increased flexibility of placement in the listening room.
The quality of sound reproduced by Gryphon Mephisto Solo is completely level-independent. It is a huge amplifier capable of delivering its best at any volume setting, from background levels to full throttle.
A Peek beneath the Hood
To generate and control such pure power, Gryphon Mephisto Solo employs custom designed Holmgren transformers with generous filtering capacity for high pulse current. The fully regulated gain stage power supply ensures long-term reliability and safety.
The carefully regulated and filtered power supply 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.
Gryphon Mephisto Solo is designed with zero global negative feedback in order to meet the dynamic demands of the very best analogue and digital source components. Exceptional bandwidth – beyond 350 MHz – is achieved despite the total elimination of feedback.
Only the finest components are employed throughout for optimal electrical and audio characteristics. 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. For each monoblock, eight 56,000 microFarad capacitors with low ESR (Equivalent Series Resistance) and 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 Solo.
By eliminating output relays, Gryphon Mephisto Solo 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.
Non-Invasive Protection
Mephisto Solo is equipped with effective protection against overheating, DC input offset, short circuit, RF and incorrect voltage supply. Slow-start turn-on circuitry analyzes and confirms the status of the transformer, bridge rectifier, power supply, reservoir capacitors and amplification circuit prior to full power-up and before accepting any input signal.
Because the advanced Mephisto Solo protection circuitry is kept outside the signal path, full protection is achieved at no sacrifice in sound quality.
The Mephisto Solo binding terminals are custom designed, massive, gold-plated connectors which provide secure power transfer with speaker cables of any diameter.
Like its inspiration, the Gryphon Mephisto two-channel amplifier, Gryphon Mephisto Solo is a unique design concept, destined to find a place only in the care of the most obsessively demanding music lover.
Features:
- Exterior design by Flemming E. Rasmussen
- Electronics design by Tom Møller
- Pure Dual Mono configuration
- Zero global negative feedback
- 40 very high current bipolar output transistors
- 500.000μF capacitor bank
- Output coupled via massive copper bussbars
- Standby current consumption < 1W
- DC servo coupling
- Frequency-independent damping factor
- Gryphon silver internal signal and power wiring
- Separate power supplies for amp and digital circuits
- Military spec. double-sided printed circuit boards
- Optimal circuit layout for shortest possible signal path
- Two separate Holmgren toroidal transformers with internal magnetic shielding
- Decoupled transformer castings
- True balanced inputs with gold-plated Neutrik XLR input sockets
- Soft start turn-on prevents triggering of fuses or circuit breakers in the home electrical system
- Gryphon gold-plated custom-built binding posts
- 12V Link for remote power on and off
- Automatic Green Bias setting via Green Bias control link or manual Low/Mid/High bias
- Non-intrusive protection system
- Designed and manufactured in Denmark
Specifications:
| Power Output | 2 x 175W @ 8Ω, 2 x 1400W @ 1Ω at 115V/230Vac |
| Noise (Unweighted, 20-20kHz) | < -80dBV |
| Noise (A-weighted) | < -83dBV |
| THD+N | < 1%, 175W @ 8Ω |
| IMD (DFD) | < 0.06%, 50W @ 8Ω |
| Output Impedance | < 0.025 Ohm |
| Bandwidth (-3dB) | 0.3 - 400KHz |
| Gain | +31.0dB |
| Input Level | 1.055 Vrms |
| Input Impedance (Balanced, 20-20kHz) | 20kΩ |
| Power Consumption (Maximum) | 2650W |
| Power Consumption (Idle, Bias H) | 700W |
| Power Consumption (Standby) | < 1W |
| AC Inlets | 2 sockets for power cords with C13 receptacle |
| Dimensions (WxHxD) | 52 x 34 x 71 cm, 108kg net |
| Shipping Dimensions | 82 x 62 x 50 cm, 140kg |