Unrivalled Pure Class A Authority | Available at Trimira Audio
The Gryphon Mephisto Stereo is a statement-level stereo power amplifier designed for reference systems where exceptional current delivery, wide bandwidth, and uncompromising Class A operation are priorities.
Built around a pure Class A, dual-mono architecture, the Mephisto Stereo combines independent channel power supplies, custom Holmgren toroidal transformers, substantial energy storage, and a high-current bipolar output stage within a massive single chassis.
With specified output of 175 W per channel into 8 Ω, 350 W into 4 Ω, and 1,400 W into 1 Ω, the Mephisto Stereo is engineered to maintain authority even with demanding loudspeaker loads.
At Trimira Audio, we recommend the Mephisto Stereo for uncompromising reference two-channel systems where maximum current capability, dynamic scale, and Class A refinement are required.
Key Features & Technological Innovations
Pure Class A & Dual-Mono Topology
The Mephisto Stereo operates in Pure Class A, with independent left- and right-channel power supplies, rectification, and gain stages.
This true dual-mono architecture is designed to maximise channel separation and minimise interaction between the two amplifier channels.
Zero Global Negative Feedback
The amplifier uses zero global negative feedback, maintaining a direct signal architecture across an exceptionally wide bandwidth.
The specified response extends from 0.3 Hz to 400 kHz (-3 dB).
40 High-Current Bipolar Output Transistors
A bank of 40 high-current bipolar output transistors provides the current capability required for difficult loudspeaker loads.
The output stage is designed to maintain strong control as impedance falls, with the amplifier specified to deliver substantial power into a 1-ohm load.
500,000 µF Energy Storage
The Mephisto incorporates a 500,000 µF total capacitor reservoir, providing substantial stored energy for demanding dynamic transients.
Combined with the amplifier's high-current power supply, this architecture is designed to maintain stable power delivery during high-output operation.
Dual Holmgren Toroidal Transformers
Two dedicated Holmgren toroidal transformers provide independent power infrastructure for the left and right channels.
The transformers incorporate magnetic shielding intended to reduce unwanted interaction between the mains supply and sensitive amplifier circuitry.
Green Bias Control
The Mephisto incorporates Gryphon's Green Bias system, allowing Class A bias to be managed according to operating conditions.
When linked to a compatible Gryphon preamplifier, the system can automatically adjust bias to balance Class A operation with power consumption and thermal output.
Technical Specifications
| Specification |
Gryphon Mephisto Stereo |
| Topology |
Pure Class A Dual-Mono Power Amplifier |
| Power Output |
2 × 175 W @ 8 Ω |
| Power Output |
2 × 350 W @ 4 Ω |
| Power Output |
2 × 1400 W @ 1 Ω |
| Global Negative Feedback |
0 dB |
| Frequency Response (-3 dB) |
0.3 Hz–400 kHz |
| Gain |
+31.0 dB |
| Signal-to-Noise Ratio |
< −83 dBV, A-weighted |
| THD + N |
<1.0% @ 175 W / 8 Ω |
| Input Impedance |
20 kΩ Balanced |
| Output Impedance |
<0.025 Ω |
| Output Devices |
40 High-Current Bipolar Transistors |
| Capacitor Storage |
500,000 µF |
| Inputs |
True Balanced Gold-Plated Neutrik XLR |
| Dimensions (W × H × D) |
520 × 340 × 710 mm |
| Net Weight |
108.0 kg |
High-Current Loudspeaker Matching
The Mephisto Stereo is designed for loudspeakers that demand substantial current capability.
Its specified output increases dramatically as impedance decreases:
- 175 W @ 8 Ω
- 350 W @ 4 Ω
- 1,400 W @ 1 Ω
This makes the amplifier particularly interesting for demanding reference loudspeakers with low-impedance regions.
System matching should nevertheless consider the loudspeaker's sensitivity, minimum impedance, phase angle, room size, and desired listening level.
Reference Two-Channel System Integration
The Mephisto Stereo's dual-mono architecture provides independent power delivery to each channel while retaining the convenience of a single amplifier chassis.
A typical reference system can be configured as:
Digital / Analogue Source → Preamplifier → Mephisto Stereo → Reference Loudspeakers
Balanced XLR connectivity provides a suitable interface for high-end preamplifiers and reference system components.
Class A Installation & Thermal Management
A 108 kg Pure Class A amplifier requires careful installation planning.
The Mephisto should be provided with:
- A robust equipment platform
- Adequate ventilation
- Sufficient clearance around the chassis
- Appropriate mains power
- Proper lifting and positioning procedures
Trimira Audio can assist with equipment placement, thermal management, mains requirements, and complete system integration.
Consult with the High-End Audio Specialists at Trimira Audio
The Gryphon Mephisto Stereo combines Pure Class A operation, zero global negative feedback, dual-mono power architecture, 40 high-current bipolar output transistors, 500,000 µF of energy storage, and substantial 1-ohm load capability in a 108 kg reference amplifier.
Trimira Audio can assist with:
- Reference loudspeaker matching
- Preamplifier selection
- Balanced XLR integration
- Dedicated mains planning
- Equipment-rack and thermal requirements
- Green Bias configuration
- Complete high-end two-channel system design
Contact the Trimira Audio specialists in Brisbane to arrange a private Mephisto Stereo audition or discuss a complete reference amplification system.
