Audio Note Ginrei 211 Mono Power Amplifier Pair

The Audio Note Ginrei is supplied as a pair of Level 4 mono valve power amplifiers.

Each independent chassis uses two 211 directly heated triode output valves operating in parallel to power one loudspeaker channel.

Maximum output is approximately 45 watts per channel into 4O or 8O loudspeaker loads.

Parallel Single-Ended 211 Operation

In a single-ended amplifier, the output valve or group of output valves remains responsible for the complete musical waveform.

Each Ginrei uses two 211 valves operating together in parallel. This allows Audio Note to retain a single-ended output-stage configuration while increasing the available power beyond that of a design using one 211 per channel.

Both 211 valves in each chassis remain active throughout the signal cycle, with the amplifier operating continuously in Class A.

Approximately 45 Watts per Channel

Each monoblock produces approximately 45 watts for its respective loudspeaker channel.

The complete pair is therefore rated at approximately 45 watts per channel rather than 90 watts per channel.

This is substantial output for a single-ended directly heated triode amplifier and provides greater loudspeaker flexibility than Audio Note's lower-powered 300B designs.

It does not, however, guarantee compatibility with every loudspeaker. Sensitivity, impedance behaviour, listening distance, room size and preferred volume should still be assessed carefully.

Pure Class A Operation

The 211 output valves remain active throughout the complete signal cycle, so each amplifier operates continuously in pure Class A.

This avoids switching the output devices on and off during the musical waveform, but it also produces considerable heat and draws power even when the system is playing quietly.

Generous ventilation and heat-resistant supports are essential for both chassis.

Zero Global Negative Feedback

The Ginrei does not use global negative feedback.

Audio Note instead places emphasis on circuit simplicity and the quality of the valves, power supplies, passive components and transformers.

Zero feedback is one of the defining requirements of Audio Note's Level 4 amplifier design system.

Audio Note Level 4 Design

The Ginrei fulfils Audio Note's published Level 4 amplifier criteria:

• Pure Class A operation
• Zero global negative feedback
• Single-ended output stage
• Valve rectification
• Directly heated triode operation
• Level 4 materials and component quality

The level describes Audio Note's internal circuit and component hierarchy rather than simply the amplifier's rated power.

Related to the Audio Note Gaku-On

The Ginrei shares its general circuit design and topology with Audio Note's Gaku-On monoblocks.

The principal published distinction concerns transformer-winding materials. The Gaku-On uses silver wherever possible, while the Ginrei combines copper primary windings with silver secondary windings.

The Ginrei should therefore be treated as its own Level 4 design rather than as an identically constructed Gaku-On under a different name.

Copper Primary and Silver Secondary Windings

Audio Note specifies copper for the Ginrei transformer primary windings and silver for the secondary windings.

The winding materials form part of the complete transformer design and are chosen alongside the core, winding geometry, circuit and intended loudspeaker load.

They distinguish the Ginrei from the more extensively silver-wound Gaku-On while placing it above Audio Note designs using copper throughout.

Valve-Rectified Power Supplies

Each monoblock has its own valve-rectified power supply using two 5R4WGB rectifier valves.

Separating the channels into two complete chassis gives each amplifier its own power supply, output stage, mains connection and loudspeaker connection.

Across the complete pair, four 5R4WGB rectifier valves are used.

Complete Valve Complement

Each Ginrei monoblock uses:

• 2 x 5R4WGB rectifier valves
• 2 x 211 directly heated output triodes
• 1 x 6V6GT driver valve

Across the complete stereo pair, the valve complement is:

• 4 x 5R4WGB rectifier valves
• 4 x 211 directly heated output triodes
• 2 x 6V6GT driver valves

The large 211 valves operate at high temperatures and high internal voltages. They should only be handled when the amplifiers have been switched off, disconnected and allowed to cool fully.

Balanced XLR Line-Level Inputs

Each amplifier accepts its line-level signal through a balanced XLR input.

A preamplifier with suitable balanced outputs is therefore required for conventional operation. The manufacturer does not publish an RCA single-ended input for the Ginrei.

Correctly wired balanced interconnects should be used between the preamplifier and both monoblocks.

Low 2.4kO Input Impedance

The Ginrei's published input impedance is 2.4kO, which is considerably lower than the input impedance of many domestic power amplifiers.

The preamplifier must be capable of driving this load through its balanced outputs without unwanted level loss, frequency-response changes or increased distortion.

Output impedance alone does not describe every aspect of compatibility, but a preamplifier with a suitably low balanced-output impedance provides the appropriate starting point.

Audio T should confirm the intended preamplifier and interconnect arrangement before the amplifiers are ordered or installed.

Input Sensitivity

Audio Note's current Ginrei specification includes a heading for input sensitivity but does not publish a numerical value.

The voltage required for full output should therefore be confirmed with Audio Note or Audio T when assessing preamplifier gain and system compatibility.

A value should not be inferred from another Audio Note 211 amplifier because circuit gain and input arrangements can differ between models.

Dedicated Power Amplifiers

The Ginrei monoblocks do not provide source selection, volume control, a phono stage, digital inputs, streaming or headphone output.

A compatible balanced preamplifier is required to control source selection and listening level.

Source components such as the Audio Note DAC 2.1x Signature must first connect through an appropriate preamplifier rather than directly to the Ginrei.

4O and 8O Loudspeaker Connections

Each monoblock provides connections for 4O and 8O loudspeaker loads.

Use the connection recommended for the loudspeaker and system. If the loudspeaker manufacturer provides specific valve-amplifier tap guidance, that advice should be followed.

Audio T can help determine the appropriate connection during system installation.

Loudspeaker Matching

The Ginrei's approximately 45-watt output provides greater scope than many single-ended valve amplifiers, but loudspeaker matching remains important.

Nominal impedance alone does not describe how demanding a speaker will be. Minimum impedance, electrical phase, sensitivity, room size, listening distance and required volume all contribute to the real amplifier load.

Relatively efficient loudspeakers with a stable impedance generally provide the most suitable starting point.

Models such as the Audio Note AN-J/SPe HE loudspeakers can be considered as part of a matched system, subject to room size and individual listening requirements.

Exceptionally Deep Chassis

Each amplifier measures 640mm deep, excluding any additional space required for cables.

Although the chassis is only 305mm wide, it is considerably deeper than most conventional equipment racks. Shelf depth must be checked before delivery.

Rear connections must not be forced against a wall or cabinet, and sufficient space must remain for safe cable bends.

37.5kg per Amplifier

Audio Note's current specification states a weight of 37.5kg for each Ginrei monoblock.

The pair therefore weighs approximately 75kg before packaging. Each chassis requires an independent support rated safely above 37.5kg.

Two people should normally handle each amplifier. The valves should be removed or protected in accordance with the manufacturer's instructions before the units are moved over any significant distance.

Heat and Ventilation

Four 211 valves operating in pure Class A across the pair produce substantial heat.

Both amplifiers require generous unobstructed space above and around their valves. They should not be installed in enclosed cabinets or directly beneath heat-sensitive shelving.

Keep the amplifiers away from curtains, papers, record sleeves and other flammable or heat-sensitive objects.

Children and pets should not be able to reach the exposed valves or hot chassis surfaces.

Mains and Electrical Planning

Each monoblock is an independent amplifier and requires its own mains connection.

Audio Note supplies versions configured for 100–120V or 220–240V AC operation at 50Hz or 60Hz, according to market.

The required operating voltage must be confirmed when ordering. The current manufacturer specification does not publish maximum power consumption for the Ginrei, so this should be checked when planning the mains installation.

Because two large pure Class A amplifiers will be used together, advice from Audio T or a qualified electrician may be appropriate where the condition or capacity of the listening-room mains supply is uncertain.

Safe Switching Sequence

Connect the loudspeakers, preamplifier and balanced interconnects before switching on either monoblock.

Source components should normally be switched on first, followed by the preamplifier and then the Ginrei power amplifiers.

When shutting the system down, switch off the power amplifiers first, followed by the preamplifier and source components.

This sequence helps prevent switching noise from upstream equipment reaching the loudspeakers at full amplifier gain.

Anodised Aluminium or Black Top Plates

Audio Note currently lists anodised aluminium and black anodised aluminium top plates for the Ginrei.

The top-plate finish does not alter the internal circuit, transformer-winding specification or rated output.

The current Audio T page does not display selectable finish options, so the required finish and production availability should be confirmed when ordering.

Key Features

• Supplied as a pair of mono valve power amplifiers
• Audio Note Level 4 design
• Approximately 45 watts per channel
• Parallel single-ended 211 output stage
• Two 211 directly heated triodes per chassis
• Pure Class A operation
• Zero global negative feedback
• Valve-rectified power supply in each chassis
• Two 5R4WGB rectifier valves per amplifier
• One 6V6GT driver valve per amplifier
• Copper transformer primary windings
• Silver transformer secondary windings
• Balanced XLR line-level inputs
• 2.4kO input impedance
• 4O and 8O loudspeaker connections
• Separate amplifier and power supply for each channel
• Anodised aluminium or black anodised aluminium top plates

Frequently Asked Questions