Of all the component-to-component relationships in an audio system it’s vinyl playback that most reminds me of a track-and-field relay race. It goes something like this: As the cue lever drops at the start of a record, a tiny signal is handed off like a baton from the vinyl groove to the stylus/cartridge, where it travels down the back stretch straight through the tonearm, and rounds the home stretch into the phonostage—the phono preamp being virtually the last leg before the signal hits the finish line—aka, the linestage preamp. By this point there is so much that has to go right or disaster ensues—and down goes the baton.
In this metaphorical race pretty much everything goes right with the solid-state XP-17 phonostage from Pass Labs. It’s a single-chassis design with internal power supply that builds upon and updates the popular XP-15. At $4300 it is comparatively mid-priced in today’s market, but for Pass Labs it represents entry-level. It is also the companion piece to the XP-12 linestage preamp that I reviewed in Issue 286. Like the XP-12 it uses a new, shielded, low-noise toroidal power supply and input-filter module. There is also an extra stage of RC filtering in its power supply for lower radiated and mechanical noise. Further, the XP–17 has an all-new input circuit that is both symmetrical and lower in noise and distortion, and offers greater drive capability. Like the upscale twin-box XP-25 and XI Phono, it was designed with a split EQ network, which is said to be more accurate and can handle greater signal levels.
Construction quality of Pass Labs gear has always been nothing short of exemplary, and so it goes with the XP-17. Heavy aluminum plates fit together with seamless integrity, creating an enclosure of vault-like solidity. The front panel visuals are a model of elegance and understatement with only a tiny power light to indicate operating status. The rear panel has a standard fused IEC socket. Designed for solo tonearm rigs, the XP-17 is also equipped with a single set of inputs and both balanced and unbalanced outputs, plus a five-way grounding post.
The XP-17 unboxes with the most typical moving-magnet values pre-set at the factory—56dB gain into a 47k ohm load. However, the numerous loading options and gain settings will easily accommodate any moving-magnet cartridge and all but the most persnickety moving coils. To that end there are two sets of eight-pole DIP switches per channel for the selection of gain and cartridge loading. (A graphic on the panel is provided for guidance.) Three capacitive loading switches enable a broad range of values—from 100pF to 750pF. For low-output moving coils, Pass suggests an initial gain setting of 66dB, rather than risk overloading the inputs of a linestage by immediately jumping to 76dB.
Even in idle with the system volume elevated, the XP-17 is consistently quiet, as I expected a solid-state unit with the Pass Labs pedigree to be. Throughout my listening sessions, there was virtually no hash or extraneous ticks or buzzes. Are there measurably quieter phonostages? The answer would be yes, but in the majority of high-end systems in less than dedicated rooms those highly sought-after noise measurements begin to swing from the perceivable to the theoretical.
In my opinion, Pass Labs components, pretty much without exception, have a voice that is consistent throughout the line. They speak fluent, refined analog with an appealing warmth, liquidity, and midrange bloom. Pass gear doesn’t colorize the frequency range but suggests a more complex dimensional component that encompasses the width and depth of soundstages and concert halls and auditoriums. I think of it as a “house sound.”
On any given day I’d typically give the XP-17 an hour or so of warmup and then listen for the superlatives to start flying from my reference system. The XP-17 has a sound that mixes an easy, almost relaxed fluidity with the iron grip of authority. Neither explicitly solid-state nor tube in character, it dishes out savory tastes of both. Treble response is smooth and open with good air on top. Bass is extended and controlled but still textured and compliant, like real music is meant to sound. Predictably the XP-17 excels with acoustic music, and the more dynamically challenging the better. On “Take the A Train” from the big-band direct-to-disc classic For Duke [M&K] Bill Berry’s ensemble was like an unstoppable juggernaut, sparkling with instantaneous transient speed—the drum kit and percussion snapping and crackling, brass cues electric with shocking authority. And Berry’s cornet solo was so blisteringly dynamic it seemed on the verge of popping speaker cones right off their baskets.
A funny thing happens with a wildly dynamic phonostage like the XP-17. The gain settings normally used for familiar recordings may need to be recalculated by a dB or so on occasion. Low-level orchestration becomes a whisper quieter, cascading kettle drums a bit grander and more aggressive. This was definitely true during the inspiring “Olympic Fanfare” from Winds of War and Peace—the Dave Wilson produced and Doug Sax mastered recording that remains a reference to this day. This track whips between clarion blasts of brass and bass drum volleys of immense impact, but also has delicate lulls of small, low-level percussion that are explicit in detail and decay. It was equally instructive to note these dynamic contrasts on Metallica’s “Nothing Else Matters” from the 45rpm Warner reissue of the Black Album. The song is like a shadowy journey that builds in stages from a delicate opening solo guitar and a distant tambourine, to Michael Kamen’s string orchestration, and finally to the explosive energy and body of the ballad itself, and then back again. Even on a heavy rock recording such as this the XP-17 navigated dynamics in high style from the grand to the granular, sharpening image focus along the way.
Vocals had shape and form—a tactile presence which for me continues to underscore a key strength of the analog world. During the lovely Carols from Salisbury [Meridian] the XP-17 reproduced the complexities and layers of choristers with organ accompaniment without smear or blur, giving each singer a sense of individuality within the larger group. The XP-17 doesn’t cramp images; rather it lets them breath within the prevailing ambience and acoustic of the venue. As I listened to one of my “go-to” purist LPs, Stravinsky’s Pulcinella [Argo]—a demonstration disc that defines what is meant by “the absolute sound”—I heard the clarity of timbre and vast movement of air produced by low brass and winds. It was the same tingle of electricity that’s conveyed by the live concert experience. As for soundstaging I turned to one of my favorite and more naturalistic recordings, pianist André Previn playing the Mozart Piano Concerto No. 17 in G Major [LSO, Boult EMI]. What makes this 1973 recording interesting to me is the positioning of the piano relative to the orchestra. Rather than being placed well forward and spot-lit in the extreme, as soloists so often are, Previn and his piano settle into a natural ambient pocket slightly downstage from the LSO, but remain an integral harmonic element of the concerto. Find an appropriately moderate volume (not too loud!), and you’ll discover a recording that truly gives you the sense of “being there” in the audience. A further illustration of the transparency of the XP-17.
As a side note, during the evaluation period I listened to the XP-17 using three different sources: my own SOTA Cosmos with SME V and Clearaudio Charisma moving-magnet cartridge, the Clearaudio Satisfy Black with the Charisma cartridge (Issue 284), and the Dr. Feickert Volare with OriginLive Silver MK3A tonearm and MoFi Master Tracker cartridge (Issue 301). Perhaps the best part of reviewing such a transparent phonostage was what the XP-17 revealed about the distinctive character of each rig—the darker weight, gravity, and stability of the SOTA; the speed, light, and delicacy of the Clearaudio; the solid foundation and precision of the Dr. Feickert.
Like every link in the relay race known as the audio chain, phonostages are subject to the vagaries of the system built around them. Bracketed by a record player on one side and a preamp on the other, the phonostage’s role is to be invisible—to convey the signal with minimal commentary while letting the music prevail in all its detail and emotion. I can’t really think of a more fitting way to describe what the splendid Pass Labs XP-17 does.
Specs & Pricing
Inputs: Single-ended on RCA jacks
Outputs: Single-ended on RCA jacks, balanced on XLR
Gain: 76, 66, 56dB balanced; 70, 60, 50dB unbalanced
Input impedance: 10–47k ohms (more than 200 user- selectable values)
Capacitive loading: 10–75 pF
RIAA curve accuracy: +/-0.1dB, 20Hz–20kHz
Power consumption: 40W
Dimensions: 17″ x 4″ x 12.5″
Weight: 20 lbs.
13395 New Airport Road, Ste G
Auburn CA 95602
A Chat with Wayne Colburn of Pass Labs
Phonostages amplify very low-level signals plus implement the RIAA EQ curve. What are the challenges unique to designing this component?
There are, indeed, big challenges in a phonostage. If we look at 76dB of gain and the RIAA curve, we are amplifying a signal almost 100,000 times. With this kind of amplification one billionth of a volt makes a difference at the speaker. Input device selection, resistor type and value, along with the layout become very important to the total noise contribution.
At the XP-17’s aggressive $4300 price, what is the strategy for balancing price and performance? Another way of asking, “What stays and what goes?”
The biggest thing that goes is a separate power supply. Double shielding on a good transformer helps, but, of course, isn’t an external supply. This preamp also doesn’t have as quiet an input stage as the XS; the input transistors need to be doubled for noticeable noise reduction. But I think this is a good solution.
How strongly does your experience designing top-tier phonostages influence your work on less expensive ones? Do the same lessons apply?
Designing something like the XS phono really helps show what is important. The XS gain setting and RIAA solution are applied directly to the XP-17. The input section is a simplified version of the XS and XP-27. You can go from the bottom up or the top down in designs. I have done both, and it may be toughest to go up, because you have to beat what you did last. In the end we have to be happy with what goes out the door and feel good about the end product the customer gets.
What role does isolation play?
Isolation electrically is the most important thing because of the high level of gain. Mechanical isolation can certainly help. We have a nice rigid sealed box, but external products can certainly be used. Even air currents can alter a phonostage (the voltage drift on a transistor in open air can be used as a thermometer), and that is one reason the case is sealed.
What aspect of the XP-17 are you most proud of?
I would say I am most proud of the value offered in the finished product.
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