Marantz PMKIRUBY/N1B Signature Reference Integrated Stereo Amplifier

The onboard HDAM SA3 and SA2 are combined with an optimized circuit design layout to help provide enhanced sound quality and performance.

Designed to deliver optimal sound by simplifying the signal path, the Marantz Musical Premium Phono EQ stage can be used with both moving magnet and moving coil cartridges thanks to a built-in MC head amplifier. Distortion is reduced by using two-stage amplification in the phono stage, and Maranz HDAMs are combined with JFETs (junction gate field effect transistors) in the output stage to provide high input impedance. The exclusion of coupling capacitors further simplifies the design, reducing signal distortion and enhancing signal purity.

The electronic volume control uses its IC to augment channel separation, dynamic range, and distortion reduction, while retaining the operational feel of an analog volume control device. This volume control is designed for high linearity as well.

Current Feedback amplification is engineered to match the requirements of Super Audio hi-res music for wide-bandwidth, high-speed reproduction. The impedance at the Current Feedback point is limited, generating a low phase shift. This reduces the need for phase compensation by minimizing Negative Feedback (NFB), simplifying the signal path, contributing to a high through-rate with enhanced transient response and sonic transparency across the bandwidth. Current Feedback also makes the amplifier insensitive to difficult speaker loads.

The PM-KI Ruby is designed to maintain the purest possible sound and support the power needed for demanding speakers. The amplifier output stage delivers up to 100W per channel into an 8-ohm load, and can cope with high-impedance speakers as well, delivering up to 200W per channel into 4 ohms. The amplifier module connects directly to the rear panel PCB to help maintain signal purity and sound stability.

Rather than build a DAC into the amplifier, which would add noise within the chassis, the PM-KI Ruby is dependent on the DAC built into the audio source, eliminating interference with the analog signals passing through the amp to help maintain an analog environment that’s as pure and clean as possible.

In addition to nickel-plated copper phono and CD analog inputs, the PM-KI Ruby features two line-level inputs and two pairs of recorder input/output jacks that allow the connection of multiple sources and recorders. You can use it as a standalone stereo amplifier for additional system configuration versatility with the power amp input, or connect the PM-KI Ruby to an external amplifier via the stereo pre-amp outputs.

Thanks to the onboard HDAM discrete modules, the headphone circuit is designed to deliver enhanced audio fidelity with a wide range of headphone types and impedances, including low-impedance headphones.

Use the included remote control to operate the PM-KI Ruby and other compatible equipment, such as the SA-KI Ruby SACD player. Remote control input and output jacks are also onboard for further configuration flexibility.