Plinius Koru Phonostage

Mid-Priced Excellence

Equipment report
Plinius Koru
Plinius Koru Phonostage

The Koru also did a superb job keeping the complex textures of Britten’s War Requiem clear as well as reproducing the composer’s spatial effects. As was so often the case, the very enterprising producer John Culshaw created a soundscape for the performance, with a boys’ chorus and an organ soloist separated off to the left and higher than the others, two male soloists toward the front and to the right, Britten’s chamber orchestra and the main chorus behind them and spread across the soundstage, while a soprano, intended to be off by herself and also higher, was placed on the left. Despite the deployment of the various forces in places throughout the hall that have their own microacoustics, as it were, the sense of an integrated space with an enveloping ambience comes through. Height cannot of course be realized in stereo, but the Koru replicated the composer’s spatial directions, which are integral to the music, and Culshaw’s aural landscape very persuasively; brass and tympani in the Die Irae were also quite stunningly registered in the famous Kingsway acoustic.

There was only one anomaly I consistently noted in my listening, which was an ever so slight reduction in apparent depth. At first I thought it was my imagination, but it held across a wide spectrum of recordings. Depending on the characteristics of your transducers, you might not even notice it, but I did, though beyond registering it in my notes, it was small enough that I soon stopped noticing it.

Apart from this, I really don’t have all that much to describe about the sound of this unit because it does its job with such undemonstrative excellence. But while I had the unit I thought I’d run some comparisons with another phonostage which is similarly priced to the Koru and has similar features, notably an adequate range of loading and level options, the tubed Zesto Audio’s Andros ($4500, Issue 222). As with solid-state, so tube electronics have been steadily improving over the years. It’s been a long time since anyone has been able truthfully to tarnish either technology with the brushes of years past: thin, edgy for solid-state; soft, mushy for tubes. And yet, paradoxically, the more they improve and thus move toward each other in sound quality, the more they seem to remain stubbornly different in the way each attempts to render reality. To my ears, anyhow, there is something about the best tube gear that continues to suggest a very subtle Wizard of Oz-like Technicolor prettification of the reproduction and about solid-state an equal pull in the opposite direction—that is, a very subtle desaturation. Or perhaps it’s a matter of texture or fineness of grain. It’s difficult to define but it is there.

I’ve often wished that those who concern themselves with more technical aspects of audio would try to determine what might account for the difference. I personally believe that with electronics of comparable specification, once levels are matched, sonic differences stem fundamentally from anomalies in frequency response and from noise and distortion. But my friends who do measurements tell me they can’t really find anything objective to account for this. Yet one of my technically sophisticated and knowledgeable TAs colleagues, who is much into measurements and gets to listen to a lot of really expensive solid-state gear, once old me that at the end of a hard day he still finds he prefers tubes because they are the equivalent to a long, relaxed “ahhhhh.” Another colleague, equally sophisticated and knowledgeable technically, used to love tubes, but now decisively prefers solid-state because, he says, when it comes to what’s on source material, “I want truth, not euphemism.” For myself, sometimes listening to the best solid- state gear I find myself vaguely hankering for something ever so slightly more flavorful or tasty, and sometimes listening to the best tube gear I find myself vaguely wanting something maybe a little less caloric. (From time to time, availability of equipment permitting, I enjoy using a combination of tubes and solid-state.)

Well, there it is: Nothing to be resolved in a pleasurable afternoon of casual comparisons, let alone in a product review. so I’ll take my leave in a conundrum. One of the best things I can say toward recommending the Andros is that there’s a lot you can say about the sound, little of it not good. One of the best things I can say toward recommending the Koru is that there’s little you can say about the sound and very little of that is not good. You pays your money, you takes your pick . . . but I can’t imagine anyone devoted to vinyl less than happy with either except, perhaps, we audio reviewers, who have to find something to write about.


Input: RCA unbalanced
Gain: 50dB, 56dB, 60dB, 66dB
Loading options: 47k, 22k, 1k, 470, 220, 100, 47, 22 ohms; input capacitance selectable 100pf or 570pf
Output: RCA unbalanced and XLR balanced
Frequency response: 20Hz—20kHz +/-0.2db referenced to RIAA curve
S/N: -80DB, 5mV input, A-weighted
THD: less than 0.01% at all levels below clipping
Dimensions: 17.75" x 3.5" x 15.75"
Weight: 12 lbs.
Price: $3900

Plinius USA
3439 NE Sandy Blvd., #128
Portland, OR 97232
(503) 662-8210