Rega Mercury Pre-Amplifier

The main development objective for the Mercury was to create a no compromise audio pre-amplifier. The Mercury is hand crafted to reveal the true potential of your hi-fi system thanks to an ultra-low noise floor which delivers exceptional dynamic range. The Mercury pre-amplifier, like the Solis, is the culmination of almost four decades of Rega electronics engineering experience in solid-state amplifier development.

The Art of Silence

Capturing the detail in a quiet performance is key to delivering an engaging sound. A well-engineered “clean” pre-amplifier preserves all those subtle details instead of masking them with unwanted noise. This fully featured reference pre-amplifier offers great flexibility and usability with the convenience of a high-performance DAC, discrete headphone amplifier, and a full colour IPS display.

Features

Fully discrete symmetrical circuitry in the core signal path
High performance DAC with S/PDIF and USB inputs
Galvanically isolated asynchronous USB input
Discrete headphone amplifier
Full colour IPS display
Custom backlit Orbit remote control
Standby mode
Lifetime warranty against manufacture defects

Amplifier Circuit

Throughout the signal path, the Mercury uses a discrete, differentially driven, fully symmetrical, high linearity and bandwidth common base voltage amplifier. Each stage uses high current drive capability, complementary Class A output stage amplifiers. This form of symmetrical amplifier circuit topology will provide the necessary voltage and current drive to enable the Mercury to perform with the minimum of distortion. Critical amplification stages use Linear Systems ultra-low noise FET (Field Effect Transistor) transistors in the differential quad pair input stages. This is the same circuit topology as used in the second stage of the Aura MC amplifier.

The Mercury uses the Alps Blue Velvet RK27 volume control (as used in the Osiris amplifier), however, this is paired with symmetrical common base driver stage amplifiers. The main outputs are DC coupled to eliminate output coupling capacitors. These outputs are appropriately DC protected by the protection circuitry.

Rega has taken circuit design leads from the Rega reference range and Saturn CD player’s post DAC analogue filter stages and implemented this topology using the symmetrical common base driver stage circuitry. This means the signal path from the analogue output of the DAC's ICs to the output of the pre-amplifier is entirely symmetrical.

Power supply

The Mercury uses a generously rated toroidal transformer feeding a linear power supply. The power supply is a discrete, symmetrical tracking power supply, using fast diodes and low noise voltage reference. Each stage has its own localised capacitance, multiplier power supply and LED referenced current generators for voltage references. To maximise headroom, the Mercury uses a higher-than-normal power supply voltage, which is 60% higher than normally found in such a pre-amplifier.

Signal Path

The pre-amplifier uses the Alps Blue Velvet RK27 volume control. The balanced inputs and outputs both use the symmetrical, common base, discrete driver circuitry. High-quality relays and Polypropylene/audio-grade capacitors are used throughout the signal path.

Digital Input circuitry

The asynchronous USB input is galvanically isolated using its own dedicated power supply, with extensive re-clocking of both the PCM and DSD clocks and data which is recovered from the USB input. The USB input has two high stability oscillator modules providing low jitter clocks for both professional and domestic sample rates. The S/PDIF input uses a Wolfson digital interface receiver and PLL, recovering low jitter data and clocks from the incoming S/PDIF data. Careful attention has been paid to clock and data integrity in both PCM and DSD modes throughout the DAC input circuitry.

The recovered PCM and DSD data feeds two parallel connected Wolfson DACs which then in turn feed the post DAC symmetrical analogue filter and amplifier stages – as mentioned in the analogue amplifier circuitry section. The analogue amplifier/filter uses Linear Systems ultra-low noise FET (Field Effect Transistor) transistors in the differential pair input stage.

Wolfson DACs were chosen for their engineering and sonic capabilities. Although they are of a legacy nature, they still offer the best sonic performance. Wolfson were careful to balance both technical and sonic performance.

Digital Input circuitry

The asynchronous USB input is galvanically isolated using its own dedicated power supply, with extensive re-clocking of both the PCM and DSD clocks and data which is recovered from the USB input. The USB input has two high stability oscillator modules providing low jitter clocks for both professional and domestic sample rates. The S/PDIF input uses a Wolfson digital interface receiver and PLL, recovering low jitter data and clocks from the incoming S/PDIF data. Careful attention has been paid to clock and data integrity in both PCM and DSD modes throughout the DAC input circuitry.

The recovered PCM and DSD data feeds two parallel connected Wolfson DACs which then in turn feed the post DAC symmetrical analogue filter and amplifier stages – as mentioned in the analogue amplifier circuitry section. The analogue amplifier/filter uses Linear Systems ultra-low noise FET (Field Effect Transistor) transistors in the differential pair input stage.

Wolfson DACs were chosen for their engineering and sonic capabilities. Although they are of a legacy nature, they still offer the best sonic performance. Wolfson were careful to balance both technical and sonic performance.

Volume Control

The Mercury uses the same Alps Blue Velvet RK27 based active volume control circuit topology as used in the Osiris amplifier; however, using the symmetrical common base driver stage amplifiers.

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

Mercury is the smallest planet in our solar system. The Rega Mercury by contrast, is the largest (by component count) and most complex electronic product Rega has ever created. The origin of this circuit extends as far back as the first Rega Elicit amplifier circa 1990. The Mercury is housed in a custom-designed, Rega CNC machined, aluminium case offering unrivalled performance, build quality and styling.

Rega Solis Power Amplifier

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.

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

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.

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 4Ω from an 8Ω 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.

Mercury Pre-Amplifier Specifications

Input - S/PDIF Co-ax And Optical:	16-24 bit @ 32/44.1/48/88.2/96/176.4/192kHz
Input - USB:	16-32 bit @ 44.1/48/88.2/96/176.4/192kHz PCM or DSD64 (DoP), Asynchronous, Power Consumption 0W (<0.5mA)
Pre-Amp - THD+N:	Typically 0.001% @ 1kHz 2V Unbalanced or 4V Balanced 0dB gain
Pre-Amp - Frequency Response:	8Hz (-0.5dB point) to 28kHz (-0.5dB point) at 0dB gain Balanced Input/Output
DAC - THD+N:	Typically 0.0045% @ 1kHz 0dBFS 2V Pre Out
Headphone Amp - Max Level 33Ω:	9V / 2.5W @ 0.1% THD+N (230V/120V)
Headphone Amp - Max Level 240Ω:	10.85V / 0.5W @ 0.1% THD+N (230V/120V)
Headphone Amp - THD+N:	Typically 0.0035% @ 1kHz 2V into 240Ω or 33Ω
Power Consumption:	50W
Power Consumption (Standby):	0.4W (activated automatically if no signal present after 20 minutes)
Dimensions W x H x D:	435 x 97 x 380mm (17 x 3.8 x 15in)
Weight:	14kg (31lbs)

Solis Power Amplifier Specifications

Power Amplifier Output (at Rated 230/120V Supply Voltage) @ 1kHz 0.1% THD:	168W RMS per channel into 8Ω305W 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:	500W at 1/8 rated power (42.5W into 4Ω)
Power Consumption in Standby:	0.4W (activated automatically if no signal present after 1 hour)
Unbalanced Input Sensitivity / Impedance:	820mV 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)

Pre + Power Amplifier Combinations

Quad 33 + 303 (Pre + 2x Power Amp)(2024 Edition)

Quad 33 + 303 (Pre + Power Amp) (2024 Edition)

Rega Mercury + Solis (Pre + Power Amplifier)