Klyne Audio Arts SK-5A preamplifier
Most preamps have what are called "features," which allow them to do many interesting things like tape cross-copying, ultrasonic filtering, stereo channel reversing, and feeding a mono source coming into one channel to both outputs. Some feature-laden preamps also have lots of multicolored indicator lamps which eliminate the need for looking to see what switches are set where, if you can remember what the different colors mean. The Klyne SK-5A, on the other hand, has few features and only one light—which tells you when it's turned on. The preamp can select between two high-level sources and phono. It has a monitor facility for one tape recorder. It has a mono/stereo switch—an unusual, and welcome, accommodation for those of us who still listen occasionally to primitive recordings because some are superbly performed. And it has a ganged volume control and a separate balance control (bless you, Stan), and a polarity switch with an intermediate -20dB mute position. Instead of additional features, the SK-5A has numerous adjustments primarily for tailoring the sound of the phono preamp, allowing you to do a few things with greater precision than I, for one, care to exercise.
Stan Klyne's preamplifiers have always been characterized by the inclusion of more adjustments than you could shake the proverbial stick at. Not every adjustment in the SK-5A is guaranteed to have a dramatic effect on the sound, but for those who can hear their effects, the adjustments are all there. As far as I'm concerned, this offers the dubious attraction of an open-ended series of listening experiments to warm the heart of any neurotic-compulsive. I do concede that Klyne, in their owner's manual, offers guidance for settings to match some of the popular cartridges—but I fear that many perfectionists will use the flexibility of these adjustments to endlessly diddle the sound of their phono system.
It reminds me of the SA-2 head amp from Counterpoint, which had a front-panel adjustment to be set for "the best sound." This allowed the user to make the device sound like a solid-state head amp or a tube head amp or an anything-you-want-in-between head amp. And what did the control do? It adjusted the amount of harmonic distortion the thing added to the signal, but that was never mentioned in either the instructions or the descriptive literature.
The SK-5A has adjustments for resistive and capacitive loading for cartridges; the desired loads are selected by small DIP switches inside the unit. You can choose the usual 47k-ohm MM-cartridge load, or any one of eleven sensibly incremented MC values ranging from 15 to 1000 ohms. For capacitors, the choice is five values, from 650 to 110pF. If you feel you need a value not represented by those switches, there are special receptacles on the circuit board that allow you to plug in resistors and/or capacitors of your own choice, without the need for soldering. (This accords you the bonus privilege of agonizing over which kind of capacitor sounds best.)
Other switches allow you to adjust the gain of the phono preamp stage from 22 to 34db, and provide for high-frequency rolloff with -3dB points from 50kHz (!!) to 16kHz to tame the fiery high end of those MC cartridges which, while popular with perfectionists, have (as far as I'm concerned) absolutely nothing going for them but extreme quickness. The only rolloff that had an audible effect in my system was the lowest one (16kHz), but it was disadvantageous, yielding a slightly closed-in effect at the top end.
Overall preamp gain is also adjustable, as with my ARC SP-11, but here it's done with resistors inserted into sockets on the circuit board. (The SP-11 accomplishes this with a significantly more convenient front-panel control.)
It's not that I disapprove of the ritualization of record playing; it's just that I don't sympathize with it. (The entirety of my own pre-play prep consists of a slow wipe with a damp velvet pad and the attachment of the SOTA Star Sapphire's vacuum-seal cap.) But every field of endeavor has its personalities that love to tweak to their heart's content, and there are a lot of audiophiles who relish any ritual which, like foreplay, heightens the tension and excitement of actually listening to recorded music by postponing the consummation as long as possible. Of course, my own enthusiasm for all these adjustments is muted by the fact that I needed to use only the adjustable phono gain provision.
The SK-5A also has two sets of outputs in antiphase. What does this buy you? Well, just by reversing the polarity of one pair of speaker wires, you can operate any stereo power amplifier with out-of-phase signals, to mirror-image the demands on its power supply. (This arrangement, christened OOPs in 1976 by Trevor Lees—Opposite channel Out of PhaSe—simulates the behavior of a two-phase AC line circuit, and has been shown to improve both soundstage breadth and overall detail of an amplifier.) You can also drive any amp capable of bridged operation, directly from the preamp, without having to switch in an additional input-inverter stage. And if you get the impression you have everything hooked up in reverse polarity, the front-panel Reverse switch inverts all signal sources.
My Ortofon MC-2000 was chosen specifically because it has a flat high-frequency response (since none of the other preamplifiers I've used offer the facilities of the Klyne), and must be operated with its own step-up transformer, which eliminates the relevance of cartridge loading. So, I shall concentrate on describing the sound of the SK-5A, and let you decide whether you could live with the uncertainty of having to set all those adjustments by ear (footnote 1).
Sonically, the SK-5A was an unusual combination of incredible detail and slightly laid-back perspective. Bypass tests revealed that the high-level section was contributing most of the preamp's "flavor," characterized by a very slight crispening of the extreme high end and an upper midrange that sounded (but did not measure) as though it was broadly dished downward by perhaps 1dB. The high-end crispness, far from what could be described as edgy, may well have been nothing more than the subjective reaction to the very slightly withdrawn upper midrange. Low-frequency performance through the high-level section was essentially flawless, replicating exactly the range and heft of the input signal.
Bypassing an actual phono source using my inverse RIAA network, as I do on every phono preamp, showed that the RIAA equalization was right on the nose; I could hear no difference between input and output signals. In actual use with phono cartridges, the sound of the preamp (or the sound of your cartridge, if you prefer to put it that way) will vary depending on the resistive loading and high-frequency rolloff (if any) you choose. What slight colorations the SK-5A has appear to originate in the high-level stages.
Footnote 1: If you truly seek a solution, there is a way. First, use only records of known and impeccable ancestry for listening. That means Sheffields, Reference Recordings, Telarcs, Wilson Audios, and the like. Second, feel The Force. Trust your instincts. If you feel that one switch setting, or combination thereof, sounds better on a statistical majority (more than 51%) of those recordings, use that setting and be done with it. Third, if you can't decide between two settings, be honest with yourself and admit that the moment you stop thinking about it, the difference won't matter anyway. Toss a coin, accept its decision, and get on with the business of listening to music, which is a lot more fun and much less harrowing.—J. Gordon Holt