Integrated Amp Reviews

To celebrate his 30 years with the company, Marantz threw designer Ken Ishiwata a birthday party in the form of an assignment: Design a new, limited-edition integrated amplifier and SACD/CD player bearing his initials. (Only 500 of each will be made worldwide.)

In a review of some Marantz separates a few years ago, I wrote that in Ishiwata, who works out of his offices in Eindhoven, The Netherlands (Marantz was once owned by Philips), the company has a unique "secret weapon." Ishiwata is a decidedly noncorporate soul who nonetheless thrives within that environment, and who brings to the line of Reference Series products he oversees an individual's passion and attention to fine detail not always appreciated in a corporate setting. I picked up on Ishiwata's strong sense of style immediately on meeting him, and wouldn't be surprised to find out that he was once a fashion photographer.

Ishiwata clearly appreciates that fine audio is both an aural and a physical experience. Coherent sonic performance is key, but looks and feel count, too. In the Marantz PM-KI-Pearl by Ken Ishiwata, everything from the sculpted looks—reminiscent of classic Marantz products—to the feel of the silky, torquey volume control, the crispness of the source switch, and the surety of the resulting click of the relay, seems to have been carefully measured and applied. You can see and hear Ishiwata introduce the PM-KI-Pearl at www.marantz.eu/kipearl/.

In the beginning was Pearl
Ishiwata's design mandate was to make the PM-KI-Pearl as good as he could within the constraints of a retail price of $3599. The similar-looking PM-15S2 integrated amplifier ($2599) came later. "You may not see so much from first glance," he told me, "but if you pay attention, you'll find KI-Pearl is a completely different product compared to the 15S2." Well, he should know.

The Pearl's fit'n'finish and overall construction quality are exceptional. The KI-Pearl is styled to match the $4000, 110Wpc SM-11S1 power amplifier that I reviewed in May 2008&, except that the Pearl's faceplate and chassis are finished in a rich, luxurious, satiny black that's unique within the Reference Series, as is the small, pearlescent, "30th Anniversary" badge on the front panel. Like the SM-11S1, the PM-15S2 is finished in traditional Marantz champagne gold.

The KI-Pearl and PM-S15S2 both output 90Wpc into 8 ohms or 140Wpc into 4 ohms, and all other measured specs appear to be identical or nearly so. Ishiwata claims that the Pearl's power ratings are conservative, and that it delivers a linear 110Wpc into 8 ohms or 180Wpc into 4 ohms.

The higher target price allowed Ishiwata to specify copper plating for the Pearl's chassis and rear plate, which are created using a special large bath that produces a consistent plating thickness, which in turn results in reduced ground impedances and eddy currents. Designers who have housed finished circuits in various materials, among them copper, steel, wood, and acrylic, report significant sonic differences among them. The PM-15S2's chassis and rear plate are made of a more conventional material, probably steel. The Pearl's 5mm-thick top plate is of solid nonmagnetic aluminum, which helps reduce vibrational modes, says Ishiwata. It also has a more attractive mesh vent than the thin, perforated one on the PM-15S2.

For the Pearl only, the support feet are individually hollowed by machine to change their vibrational modes, and are secured to a heavier bottom plate. Ishiwata says, "You'll be shocked by how much those mechanical differences can contribute to better sound!" Given how much the sound of already well-constructed components improved when I placed them on a Harmonic Resolution Systems stand, I'm not surprised at all.

The PM-KI-Pearl's power supply is much bigger and more lavishly equipped than the budget version's, with a larger toroidal transformer mounted to a 2mm-thick bottom plate that reduces flux leakage, as well as higher-quality electrolytic capacitors and rectifiers. Most of the decoupling electrolytic capacitors and the low-value capacitors are also of a higher quality than the S15-S2's, which, he says, results in smoother mid-high and high frequencies.