SPEC RSA-717 EX INTEGRATED AMPLIFIER

INTEGRATED AMPLIFIER

Fairly new to the audio scene, Japanese manufacturer Spec and its designer Koichi Yazaki have delivered a quirky little amplifier with a unique exterior and a lovely, natural sound quality.

Spec Corporation is something of a rarity: a newly-founded (2013) high-end audio company that manufactures its products in Japan…though some might say that because Spec is a Japanese company (founded by Syuzou Ishimi), manufacturing its products in Japan makes perfect sense.

The company’s product line is a little eclectic, because although it includes stereo amplifiers and a phono preamplifier, it also ranges a string-driven turntable, a device called a ‘PSP-901EX Real Sound Processor’ that says it ‘absorbs back-emf from speaker systems’ and a range of Mica capacitors that electronic technicians can use to replace or bypass the capacitors in valve amplifiers made by other manufacturers.

Indeed the company places more importance than most on the design and manufacture of the capacitors used in its products. One example of this is the fact that it uses not only its own Mica capacitors in its products, but also ‘paper-in-oil’ capacitors manufactured by Arizona Capacitors (US) to the specification of capacitors originally made by West Cap. It also uses SiC (Silicon Carbide) Schottky diodes rather than standard silicon types, due to their lower reverse leakage current and higher reverse voltage (two of the reasons they’re specified for use in aerospace applications). In common with all other amplifiers made by Spec, the RSA-717 EX is equipped with a Class-D output stage manufactured by Californian outfit International Rectifier.

The chief designer at Spec is none other than Koichi Yazaki, who joined Spec after working at Teac and Pioneer, but I wondered if he’d ever worked for Japan Air Lines, because the power switch on the front panel is like nothing I’ve ever seen before. According to Craig Johnstone, of local Australian Spec distributor Audio Heaven, they’re used in aircraft cockpits in applications where it’s essential that a switch can’t be inadvertently ‘bumped’ from one position to another.

Although the power switch looks like a standard (well perhaps not-so-standard!) twopole toggle switch, you can’t just flick the switch lever up and down. In order to move the lever, you need to grasp it firmly, then pull it outwards at the same angle the toggle is pointing. Once this is done, the switch can be moved up or down, after which a spring pulls it back in towards the front panel where it locks, after which it cannot be moved without repeating the same operation (in reverse).

The ‘On’ LED immediately adjacent to the power switch glows green when the amplifier is on… as you’d expect, but the ‘Off’ LED, on the other hand, has a rather strange action. When the amplifier is turned on it glows red for a short period, then pulses and turns off. When the amplifier is turned off, the red LED glows brightly, then once again pulses on and off weakly before extinguishing completely.

Although it’s also a toggle switch, the speaker switch is a standard toggle switch, without a safety lock. Well, once again, perhaps it’s not quite standard: the switch

has a tiny ‘chameleon’ LED built into its end which, so far as the RSA-717EX is concerned, glows green when the speaker output is active, and red when the speaker output is off. A quirk common to both switches is that ‘Off’ is the downwards position of the switch, and ‘On’ is the upwards position, which is the convention in Japan and North America, but is the ‘wrong way around’ for Australians, which may cause some initial confusion.

The volume control appears (and feels) as if it’s a standard analogue potentiometer, but it’s not: It’s a rotary encoder that instructs a solid-state volume circuit in order that, according to Spec ‘ audio quality is not affected depending on the volume (level adjustment knob) position.’

The input selector has only four positions, all of which are line-level: There is no phono input. Line 1, 2 and 3 are all unbalanced inputs (via RCA sockets), while Line 4 is balanced (via XLR sockets). Although four inputs should be sufficient for most applica- tions, some users might have found an extra one or two quite handy. It would also have been handy to have a balance control to help compensate for poor recordings and/or for speaker level compensation. Although the Spec RSA-717 EX has a headphone socket, it’s a small 3.5mm phone type. I would have much preferred to see a full-sized, 6.35mm phone jack, because they’re physically and electrically more robust, and would also mean that you didn’t have to use an adaptor when using professional-grade headphones… which are the type you’d expect to be using with a component such as the Spec.

The rear panel of the RSA-717EX has just a single set of high-quality speaker terminals. All the RCA input terminals are gold-plated: it would have been nice if the XLR terminals had been too.

The Spec RSA-717EX is a ‘non-standard’ size, somewhat smaller than usual, measuring just 375mm wide, 350mm deep and 95mm high.

The aluminium chassis is beautifully finished with an attractive anodised coating. The wood panels at either end of the amplifier are made from a combination of Japanese spruce and Japanese maple.

Spec uses not only its own Mica capacitors in its products, but also ‘paper-in-oil’ capacitors manufactured by Arizona Capacitors (US) to the specification of capacitors originally made by West Cap. It also uses SiC (Silicon Carbide) Schottky diodes rather than standard silicon types, due to their lower reverse leakage current.

The volume control appears (and feels) as if it’s a standard analogue potentiometer, but it’s not. It drives a rotary encoder...

These panels are said to be made ‘ by craftsmen in the historic town of Hida Takayama in Japan.’ Spec claims that the use of these two timbers: ‘ cuts off vibration effectively from the outside.’

The Spec RSA-717EX can be controlled by remote, but a remote control is not included with the amplifier: it’s available only by separate purchase, for $750. Not providing a remote with a product that costs nearly $7,000 seems a bit niggardly. As for the remote’s high price, one reason is that the circuitry for remote operation isn’t built into the amplifier at all, so if you go the remote route, you’re buying not only the remote control itself, but also a separate output ‘receiver’ that plugs into the ‘remote’ jack on the rear panel, and a power supply for that receiver. In my view it would have been better to either integrate the remote circuitry and include it in the retail price or not offer any form of remote control at all… even though this latter approach may have upset couch potatoes around the world.

IN USE AND LISTENING SESSIONS

It seemed appropriate to kick-off my listening sessions with Sydney-based hip-hop artist Tuka’s album ‘Life Death Time Eternal’ and it certainly proved a good choice to demonstrate the Spec RSA-717EX’s many sonic strengths. The simple but effective bass lines played by Michael Meagher were delivered with the classic ‘steel fist in velvet glove’ feel by the Spec in such a way that they were pervasive but never dominating, particularly notably on My Star, which also offers classic electric guitar sound by Counterbounce (Pip Norman) and backing vocals that include infectious unison whistling.

The Spec also showed its mettle on the moody intro to State of Mind where drums and bass dredge the depths of the sonic mel- ange, before the tortured sound of a synth interrupts the croaked lyric and ethereally-echoed backing voices. The resulting fat, multi-layered sound was delivered perfectly by the Spec RSA-717EX, with the amplifier never losing the thread of the music, or failing to reveal any of the layers.

It was an altogether cleaner sound to Josh Ritter’s album ‘Sermon on the Rocks’ but the greater use of real instruments allowed a more detailed evaluation of the tonal qualities of the Spec, and I can report that designer Koichi Yazaki has nailed it, such that the company’s ‘Real Sound’ catch-phrase certainly rings true. The clarity of Ritter’s vocal rang through as life-like as a live performance and Zac Hickman’s acoustic bass was as woody and natural as you’d expect. The transients of the percussive sound, courtesy Matt Barrick’s drum kit, were delivered brilliantly by the Spec. On Seeing Me Round, all the musicians get a brief shot in the spotlight, so I enjoyed deliciously natural, realistic sounds from acoustic and electric guitars, synths, organs… you name it, including a lyric for the ages. Rolling Stone magazine said Sermon was ‘ awash with biblical imagery and mythological Americana’. True enough, but it’s also awash with great music.

In terms of amplifier/speaker matching, I found the Spec to be very tolerant: it sounded fabulous with all the speakers I tried, irrespective of their impedance. If you routinely listen at loud to very loud levels I think you’ll find that the RSA-717EX will, however, work best when it’s paired with high-efficiency loudspeakers—those with sensitivity ratings of 89dBSPL or more: it just seemed to sound more dynamically unrestrained with these higher-efficiency designs when playing at these volume levels. If you’re not listening at high levels, and/or you have a smaller room, lower-sensitivity speakers will likely suit just as well… but make sure you take them for a test run before committing to purchase.

CONCLUSION

An auspicious debut to our Australian shores for this quirky little Japanese amplifier. The exterior finish is unique and the amplifier has a lovely, natural sound quality that makes it very easy on the ear. Fawad Malhotra Readers interested in a full technical appraisal of the performance of the Spec RSA-717 EX Integrated Amplifier should continue on and read the LABORATORY REPORT published on the following pages.