REGA Solis Reference Power Amplifier

Solis REF NEW Experience the pinnacle of audio performance with the Solis stereo power amplifier. Designed and hand-built in England, this powerhouse is meticulously engineered for those who demand the very best in audio quality, design, and craftsmanship. Each component has been carefully selected for its superior audio properties, ensuring that every track you play, in every format, is delivered with breath-taking clarity and detail. Next level performance, zero compromise Engineered to drive the most demanding of speakers, the Solis is the perfect partner for the Mercury Pre-amplifier. Our engineering team have spent the last four years obsessively developing and fine tuning the circuit to create the most engaging and accurate performance. The advantage of using a separate chassis for the pre-amplifier and power amplifier allows the low voltage, sensitive circuitry to be isolated from the high current, power amplifier circuitry. This reduces interference between the pre-amplifier and power amplifier leading to a less noisy signal path and a cleaner signal. Also compatible with the Rega Aethos stereo power amplifier. KEY FEATURES ■ Fully symmetrical discrete circuitry in the signal path ■ Balanced and unbalanced inputs ■ 168W into 8Ω / 305W into 4Ω ■ Short circuit protection ■ Thermal cut-out and DC Protection ■ Standby mode (user selectable) ■ 12V trigger ■ Independent MUTE function ■ Compatible with Mercury pre-amplifier and Aethos stereo amplifier ■ Lifetime warranty against manufacture defects AMPLIFIER CIRCUIT The Solis uses a fully symmetrical circuit throughout with a differentially driven, low distortion, high linearity and bandwidth common base voltage amplifier driver stage. This type of symmetrical circuit topology will provide the necessary voltage swings to enable the Solis to drive any speaker system with the minimum of distortion. Twelve (six per channel) Sanken 130-Watt 15A high frequency, multi-emitter output transistors are used in a "triple" high current output stage enabling the Solis to drive even the most awkward of speaker systems with ease. The cascoded differential input amplifier uses two, low noise, LED referenced, current generators. The open & closed loop feedback levels and gain bandwidth product components are optimised to give a tight and controlled sound stage, especially at the low frequency end of the audio range. Nichicon audio grade capacitors are used in critical bypass and decoupling positions. Electrolytic capacitors have been bypassed with polyester capacitors where necessary, improving on the HF performance. HTR non-inductive resistors are used in the output stage. All these features amalgamate to create the supreme level of performance found in the Solis. POWER SUPPLY The Solis uses two, low-noise, custom designed, 330VA toroidal transformers using high-grade fully bonded core material. This reduces mechanical noise from the transformer when the transformers are operating under arduous mains (line) conditions with high levels of asymmetric mains (line) distortion. These transformers combined with 40,000µF of Rega K-Power smoothing capacitors per channel, provide ample current to drive the hardest of loads, effectively doubling the power into a 40 from an 80 load. All the power supplies utilise fast recovery rectifier diodes throughout. (Fast diodes generate less high frequency switching noise therefore giving rise to a cleaner DC). The input and low-level driver stages are fed from a regulated symmetrical tracking power supply with a low noise voltage reference, which provides a fully stabilised, low noise voltage, ensuring the highest level of sonic purity. All the dedicated audio power supplies feed only the audio circuits. PROTECTION The Solis has an extensive protection circuit that monitors the speaker DC levels and amplifier temperature. This amplifier protection circuit works in conjunction with the supervisory circuit. The Solis uses microcontroller based slow start, standby and power supply supervisory circuits to power-up the two massive transformers from standby, keeping the in-rush current to a minimum. The supervisory circuits also control the no-signal standby power down function to comply with current Eco requirements. The slow start, power supply supervisory microcontroller and protection circuits have their own dedicated power supply galvanically isolating it from the audio, thus, keeping the audio signal path as pure as possible. SIGNAL PATH ICEL polypropylene capacitors, HTR non-inductive resistors and relays are used in the signal path. BALANCED / UNBALANCED For normal domestic Hi-Fi, Rega recommends the use of unbalanced connections, for optimum sound quality. The Mercury and Solis core circuits are unbalanced. Because of this, additional circuitry is needed to create a balanced system. Although the balanced input and output circuits in the Mercury are very high performance, additional circuits will always add some inherent noise/distortion to the signal. True balanced systems are widely used on professional audio equipment. This requires all parts of the amplification and cables to be running as a "balanced system". Balanced connections are used where long cable runs are necessary, particularly in studio and PA applications. They help to cancel unwanted noise pickup in the long runs of cable. This noise rejection is why balanced circuits are used in professional equipment. Balanced circuits do not offer an intrinsic increase in sound quality over unbalanced circuits, as is sometimes perceived within the Hi-Fi Industry. Another attractive aspect of balanced systems is they use the "XLR" style plugs. These are physically larger and can have a subjectively better insertion feel than standard Phono/RCA style plugs. This can often lead to perceived value and contact quality, where in practice, there is no objective improvement. The vast majority of Hi-Fi equipment is an unbalanced topology (sometimes called single ended). In most circumstances, balanced connections are inappropriate for domestic Hi-Fi equipment. The increased noise rejection is not necessary and does not outweigh the drawbacks of additional circuit complexity. On expensive equipment, balanced connections are sometimes provided for use in recording studios or to satisfy the perception that balanced connections are better. Rega knows that some of its products are used in the studio arena, so we have added balanced XLR connections, implementing additional circuitry. HISTORY AND INNOVATION The Solis amplifier is the culmination of almost four decades of Rega engineering experience in solid-state amplifier development. This expertise, combined with the "clam shell" Elicit and Exon amplifier circuits, laid the foundations for the advanced amplifier circuit found in the Solis. All components selected during the design process were chosen for their sonic and electrical properties. Rega has applied enhancements to the thermal stability and heatsinks of the previous version of the power amplifiers, along with state of the art, surface mount technology perfected over the last 15 years. When combined with the Aura phono stage and Mercury pre-amplifier, the listener will have a fully symmetric, discrete system from source to speaker. TECHNICAL SPECIFICATIONS Power Amplifier Output (at rated 230/120V supply voltage) @ 1kHz 0.1% THD 168W RMS per channel into 8Ω 305W RMS per channel into 4Ω THD+Noise at 100W into 8Ω measurement bandwidth 22Hz to 22.4 kHz Typically 0.015% at 1kHz Unbalanced Input Sensitivity 820mV at 35kΩ Balanced Input Sensitivity 1.64V at 26kΩ Power Amplifier Gain 33.3dB Frequency Response at 100W into 8Ω (Unbalanced input) 15Hz (-0.5dB point) to 30kHz (-0.5dB point) Power Supply (as marked) AC supply 230V / 220V / 120V / 100V nominal ±10% Power Consumption Power Consumption 500W at 1/8 rated power (42.5 W into 4Ω) Power Consumption in Standby 0.4W (activated automatically if no signal present after 1 hour) Unbalanced Input Sensitivity / Impedance 820 mV at 35kΩ Balanced Input Sensitivity / Impedance 1.64V at 26kΩ Dimensions (WxHxD) 435 x 140 x 385mm (17 x 5.5 x 15in) Weight 24.8 kg (54.7lbs) For full technical specifications, download Solis - User Manual EN - Ver 1 below. DOWNLOADS ⬇ Solis - User Manual EN - Ver 1 342KB pdf ⬇ Solis - User Manual FR - Ver 1 1.18MB pdf ENVIRONMENTAL LABELLING OF PACKAGING ⬇ Solis environmental packaging data 65KB pdf “ The soundstage was wide and deep. I wasn’t sure I’d ever heard a more transparent picture or a greater sense of kinetic aliveness than I did through the Rega pair. The experience felt unusually physical ROBERT SCHRYER – PMA MAGAZINE PMA – Review November 2025 the-ear.net December 2025