Marantz has been designing and making amplifiers for more than 65 years, and for 40 of those the products have reflected expertise of Ken Ishiwata. Now, to mark his four decades with the company, the PM-KI Ruby amplifier has been developed and tuned by a highly experienced engineering team led by KI himself. It features a fully discrete two-stage design with separate power supplies for the pre-amplifier and power amp — plus, a moving coil/moving magnet phono stage complete with Marantz Musical Premium Phono EQ circuit and Marantz HDAM technology for signal purity and exceptional audio quality. PM-KI Ruby is built on a vibration-resistant double layer chassis with thick aluminium panes for rigidity and features a laser-engraved Ken Ishiwata signature to commemorate his legacy.
- Engineered and extensively tuned legendary Marantz sound master Ken Ishiwata and his team, drawing on more than 65 years of Marantz amplifier design knowledge
- Marantz high-resolution preamplifier stage with proprietary HDAM technology
- Switching power amplifier design derived from flagship PM-10 amplifier
- Generous output: 100W + 100W (into 8ohm), 200W + 200W (4ohm)
- Fully-discrete, two-stage design for signal purity, with separate power supplies for preamp and power amplifier sections to reduce interference
- Toroidal transformer dedicated to preamp for clarity and powerful sound
- Current feedback design with newly-developed wide-range circuitry
- HDAM® SA3 circuitry for clean signal and optimal dynamics
- MM/MC Phono input with new discrete Marantz Musical Premium Phono EQ circuit
- Thick nickel-plated copper independent input terminals for CD and Phono, plus Marantz-original high-quality/high-purity copper-plated speaker terminals
- Linear volume control with new electric volume system
- High-quality construction with double-layer chassis, 5mm thick aluminum top lid, solid aluminum front and copper-plated chassis
- High-grade, carefully selected audio parts: ultra-low leak current Schottky diodes, low noise complementary transistors, high-grade resistors, newly developed custom electrolytic capacitors, audio grade film capacitors and mica capacitors.
- Laser-engraved Ken Ishiwata signature and Ruby motif, marking Ishiwata’s 40-year Marantz legacy
Celebrating 40 Years of Passion
Designed to celebrate the 40-year anniversary of legendary Marantz sound master, Ken Ishiwata, PM-KI Ruby features pinnacle performance that’s synonymous with Marantz excellence. Complete with thoughtful engineering, painstaking tuning and extensive listening sessions, PM-KI Ruby achieves the elevated output worthy of its name. Elegantly shows Ishiwata’s laser-engraved signature to commemorate the design and heightened listening experience that honours the decades-long partnership between him and Marantz.
Extensive Sound Tuning
Led by Ken Ishiwata’s extensive, meticulous approach to tuning, the larger Marantz engineering team applied more than 65 years of experience and HiFi knowledge to create PM-KI Ruby, resulting in a final product that is a testament to Ken Ishiwata and the Marantz legacy.
Marantz HDAM Technology
Marantz developed its own discrete circuit boards called Hyper-Dynamic Amplifier Modules, or HDAMs, to replace the chip-based amps used elsewhere. Using discrete surface mount components with short mirror-image left and right signal paths, HDAMs outperform the regular integrated Op-amps dramatically in Slew Rate and noise level. The result is much more dynamic, accurate and detailed sound. Over the years, Marantz has developed different HDAMs to fit the particular requirements of players and amplifiers. The PM-KI Ruby uses the latest high-grade SA3 version. Combined with optimized circuit design layout and carefully selected components, the PM-KI Ruby provides exceptional sound quality and performance.
Marantz Musical Premium Phono EQ
Designed to deliver optimal sound quality by simplifying the signal path, the Marantz Musical Premium Phono EQ stage in the PM-KI-Ruby amplifier can be used with both moving magnet and low-output moving coil cartridges, thanks to a built-in MC head amplifier. Distortion is reduced by using two-stage amplification in the phono stage, and Marantz HDAMs are combined with JFETs (junction gate field effect transistors) in the input stage, giving high input impedance. The exclusion of coupling capacitors further simplifies the design, reducing signal distortion and enhances signal purity.
High Quality Volume Control
Newly developed electric volume control uses the latest volume control IC to realize better channel separation, dynamic range and distortion-reduction, while retaining the operational feel of an analogue volume control device. The amplifier employs new Marantz-designed electric volume control for high linearity and best-in-class channel separation.
Current Feedback Amplifier
Current Feedback amplification is a well-known, Marantz-original circuit technology, thoughtfully designed 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 very low phase shift. Marantz Current Feedback amplifiers reduce the need for phase compensation by minimizing Negative Feedback (NFB). This simplifies the signal path and results in a high through-rate, excellent transient response and superb sonic transparency across the full bandwidth. Unlike conventional Voltage Feedback topology, Current Feedback also makes the power amplifier insensitive to difficult loudspeaker loads.
Balanced Power Amplification
Drawing on design elements of the PM-10, the PM-KI Ruby is built to leverage enhancements, maintain the purest possible sound and support the power needed to drive the most demanding speakers. The amplifier output stage of the PM-KI Ruby allows a large power output, delivering 2x100W into an 8ohm load, and easily copes with high-impedance speakers thanks to a 2x200W output into 4ohms. The amplifier module connects directly to the rear panel PCB on the PM-KI Ruby to maintain signal purity and sound stability.
Pure Analogue Design
The purely analogue design of the PM-KI Ruby contributes to its noise-reduction structure and clean build. Rather than build the DAC into the amplifier, which would add noise within the chassis, Marantz built the PM-KI Ruby without one and then implemented the DAC in the SA-KI Ruby Super Audio CD Player. This eliminated interference with the delicate analogue signals passing through the amp, maintaining an analogue environment that’s as pure and clean as possible.
Carefully Selected Components
Marantz has a steadfast reputation for choosing the best-possible components for its Premium Series products. The Marantz alternative to the “amplifier on a chip” IC components, the HDAM, is a miniature amplifier module built entirely of discrete components. Marantz engineers selected and optimized the HDAM through extensive listening in dedicated Marantz facilities in Europe and Japan. Extensive, painstaking and meticulous tuning has long been the secret of exquisite-sounding Marantz amplifiers. During the development stage, every part is carefully selected, tested and validated by Marantz audio engineers to ensure audio perfection every time you listen.
Multiple Analogue Inputs and Outputs
In addition to phono and CD analogue inputs, the PM-KI Ruby features two line-level inputs and two pairs of recorder input/output jacks that enable the connection of multiple sources and recorders. Use the PM-KI Ruby as a standalone stereo power amplifier for additional system configuration versatility with the included power amp input, or connect the PM-KI Ruby to an external power amplifier via the stereo pre-amp outputs.
Dedicated Headphone Output
Using Marantz-proprietary HDAM discrete modules, the headphone circuit delivers superb audio fidelity with the widest range of headphone types and impedances, including low impedance headphones.
System Remote Control
Use the elegant remote control to operate the PM-KI Ruby as well as the complementary SA-KI Ruby Super Audio CD Player. The PM-KI Ruby features remote control input and output jacks for additional remote control configuration flexibility.
Built to Perform
Like the complementary SA-KI Ruby Super Audio CD player, the PM-KI Ruby integrated amplifier is constructed to the highest standards with a copper-plated chasses to reduce mechanical and electrical interference. A front panel constructed from thick, heavy, non-magnetic aluminum panels and an 5mm dense aluminum top cover eliminate added interference. Nickel-plated copper independent input terminals for CD and Phono plus Marantz-original high-quality/high-purity copper-plated speaker terminals ensure the best signal possible.
More Than 60 Years of Audiophile Heritage
Founded in 1953, Marantz has a long and rich history of designing audio components embraced by music lovers and critical listeners around the world. Because Music Matters, the PM-KI Ruby carries on our long tradition of delivering a best-in-class listening experience for music and cinema.