Audio Research • PH8 Phono Stage
One of my earliest memories from when I started getting interested in high-end audio (or hi-fi as we called it back in the UK) is an advert for a Warrington-based dealer called Doug Brady Hi-Fi. The gear in the ad was all very drool-worthy for this then-neophyte audiophile: a pair Mission 770 Freedom speakers, a Linn LP12 turntable, a Krell KSA50 power amp, and an Audio Research SP8 preamp (the latter sitting atop a Mission Isoplat and Target stand, a preamp set up I have nearly duplicated—I have an SP9 rather than an SP8—all these years later!). Between the two speakers was a serious-looking gentleman in a jacket and tie (the Brits love their ties; personally I can’t stand ’em!), and across the top of the ad was its headline, “You really must hear this”.
I can’t recall if my love affair (or, perhaps more accurately given my impoverished student status at the time, lust affair) with Audio Research gear started with that ad, but the time (the mid 1980s) is about right. Brushed aluminum (or should that be aluminium?) face plates, grab handles, a serious, no-nonsense aesthetic, and the warm glow of tubes from within: what’s not to love? Add a reputation for good sound quality via rave reviews in the UK press (I didn’t start reading North American magazines until a few years later), and my curiosity was piqued.
Since those early days I’ve had many opportunities to listen to Audio Research equipment, mostly in dealers’ stores and at trade shows. A few years ago, I managed to squeeze my budget enough to purchase a used SP9 Mk 2, which has remained my reference preamp since then.
Skipping forward a few years, I was talking with Audio Research’s Dave Gordon about the possibility of a review sample. “How about we start with a PH8 phono stage?”, he suggested. I readily agreed, but expressed some reservations about partnering it with my SP9—I didn’t want the latter to short-sell the PH8. “Well,” said Dave with a twinkle in his eyes, “why don’t we lend you one of our new LS17 SE line stages as well?”. With an offer like that, how could I possibly refuse?
The PH8 is the middle model in Audio Research’s trio of full-sized phono stages, sitting comfortably between its smaller and bigger brothers (the PH6 and Reference Phono 2 SE respectively). (I should add that since I wrote this review, Audio Research have announced their flagship two-box phono stage, the Reference Phono 10.) It has a single pair of single-ended inputs and outputs, and features user-selectable input loading resistance. Unlike its bigger brothers, the PH8 offers only RIAA equalisation, but this is not likely to be a serious drawback for the majority of users.
The rear panel houses the gold-plated input and output RCA sockets, an earth post, and a 15A IEC mains socket.
The front panel, which is made from a 6 mm thick sheet of machined aluminum, is available with either a natural or black anodised finish; the purchaser can also specify the finish of the front handles (natural or black anodised). The default is for the handles to match the front panel, but I find black handles with a natural faceplate aesthetically pleasing.
In addition to said handles, the front panel is also home to a vacuum-fluorescent display, just below which are four round aluminum buttons. The buttons control the power, mono/stereo mode, the input load (47K, 1K, 500, 200, and 100 Ohms), and mute functions. The display has eight selectable brightness levels, and may also be turned off (in this state nine pixels remain dimly lit to remind the user that the PH8 is still powered on).
The front panel controls are duplicated on the included remote control, which also has buttons for controlling the display’s brightness, and a nifty feature that shows how many hours the tubes have been in use. I’m obliged to mention that I think the plastic remote control, while perfectly serviceable, feels a bit cheap for a product in this price category and quality aspiration. It’s not a big deal, but something that should be pointed out. And, I hasten to add, it does not reflect on the excellent build quality of the PH8 itself: the PH8’s fit ’n’ finish are up to the high standards we’ve come to expect from Audio Research.
Inside the case is a single large circuit board. The phono circuitry, which is derived from the Reference Phono 2, uses a dual-mono configuration and benefits from a number of circuit and parts improvements over its predecessor, the PH7. More than half the case is dedicated to the power supply, which is implemented using a huge new R-core transformer (I’ve seen smaller transformers in some integrated amplifiers!), a large capacitor energy reservoir, and tube regulation (both a 6550 and a 6H30 are used in the power supply). The latter are the same as used in the Reference Phono 2 and Reference 5 line stage (but presumably not with quite the same finesse).
Also inherited from the Reference Phono 2 are the capacitor types used in the audio circuitry, including the same coupling and Teflon capacitors used in the RIAA stage and as bypass capacitors. Two 6H30 dual triode tubes and low-noise FETs are used in the gain stage (providing 58 dB of gain), and the PCB is made from the same material as those in the Reference series.
Setup and Listening
The first thing one must do when setting up the PH8 is install the four tubes, which are safely packed in foam for shipping. After removing the top cover (and its attendant 14 screws), the tubes are inserted into their sockets; thankfully, both tubes and sockets are clearly labelled. After some careful listening, I decided that an input loading of 100 Ohms most suited the Lyra Atlas I used for this review.
I usually have all my audio gear connected to the mains via my Furman 15PFi power conditioner, so that’s how I performed the burn in and early evaluations. However, the note accompanying the review samples requested that a power conditioner not be used, at least not without a careful listening first. Once the burn in was complete, I compared the performance of the PH8 both direct and via the Furman (using each of the Furman’s set of power outlets). Much to my surprise, the direct connect was audibly superior—especially in the sense of detail and dynamics—so that is how I conducted all subsequent listening. The 15PFi’s high current amplifier output sounded the least compromised, but even it was a small but noticeable step down in quality.
The good news is that the PH8 sounds pretty damn good out of the box; the bad news is that Audio Research recommends 600 hours of break-in time! This is primarily due to the Teflon capacitors, whose dielectric takes a notoriously long time to form. During the break-in period the sound quality is bit of a roller coaster ride, in that it is up and down. At times the sound was good, at other times not so much: the sound became darker at times, and less involving. The key point is if you’re evaluating a PH8 and considering a purchase, use the tube hour meter to ensure that it is fully broken in. To help speed up the break-in process, I used Granite Audio’s excellent burn-in CD. Note that Audio Research caution against leaving the PH8 permanently powered on, so I used the burn-in CD when not actually listening to music until I went to bed for the night.
I evaluated the PH8 in two phases: the first by inserting it into my system in place of my usual phono stage and using my SP9, and the second by using it in conjunction with the LS17 SE.
One of my first impressions of the PH8 was its bass, which is deep, powerful, and authoritative. By this I mean that the bass doesn’t necessarily go much deeper than other phono stages I’ve used, but it plumbs the depths with a greater sense of ease. A motoring analogy that springs to mind is this: both an everyday car and a sports car are capable of high speeds, but the sports car will get there with much less apparent effort than the less powerful one. The PH8 is as at ease reproducing relatively complicated bass lines (for example, those in Jean-Michel Jarre’s Equinoxe [MFSL/Disques Dreyfus 1-227]) as it is simpler ones, like those in Mike Oldfield’s Tubular Bells [Virgin Records V2001].
Grain is vanishingly low: the tinkling of Tubular Bells’ opening piano and tintinnabulation of the bells are free from grit, haze, hash, and other nasties that besiege lesser units. Sometimes the time-worn analogies are the best: inserting the PH8 into my system really had the aural equivalent of removing a pane of glass. This lack of grain makes it that much easier to not only hear the air around the instruments, but to hear the sounds of the acoustic space in which the music was recorded. It also has a way of ruthlessly revealing details about the recording to which we, as listeners, probably aren’t supposed to be privy. Take, for example, part of Peter Gabriel’s Sledgehammer, from So [Classic Records/Real World Records PG 7-45]. Listen carefully, and you will clearly hear that a different take was used part way through the phrase, “You could have a big dipper/Going up and down, all around the bends”.
On the right gear, Tubular Bells has a very wide soundstage, extending far beyond the speakers. I pleased to report that the PH8 doesn’t disappoint here either, presenting a soundstage that is as wide and as deep as the recording (and ancillary gear of course!) permits. As cavernous as the soundstage is, however, imaging isn’t quite as holographic as it could be. One of my acid tests for pinpoint 3D imaging is the Nasal Choir from Tubular Bells. On systems with laser-like focus, I can identify the location of each pair of nostrils that make up the choir more readily than I could with the PH8 (I freely admit that my SP9 may be at least partially the culprit here).
Moving onto some classical music, I played Prokofiev’s Lieutenant Kije [Classic Records/RCA Victor LSC- 2150]; when evaluating equipment I usually just listen to the first two movements, but felt compelled to listen to the whole piece this time around. The dynamic swings are breathtaking—I almost jumped out of my skin when the bass drum whacks played during the first and third movements, even though I was expecting them! The wall of sound from the bass drum whacks and gong in The Great Gate of Kiev from Mussorgsky’s Pictures at an Exhibition on The Power of the Orchestra [Analogue Productions/RCA Victor AAPC 2659-45] are another example of the PH8’s ability to recreate space.
Again, the PH8 presents a spacious and detailed soundstage. I could clearly hear the sound of the snare drum reflecting off the rear right wall slightly after the initial sound came from the rear left. Similarly, the off-stage opening trumpet solo.
Sticking with Lieutenant Kije, the air around the bells in Troika and the celeste in Romance was palpable, and again, there wasn’t a hint of any grain that I could hear.
Switching genres once more, I listened to a couple of tracks with a very intimate sound: Bill Henderson’s Send in the Clowns [Jazz Planet JP 0779-12] and Dusty Springfields’ The Look of Love from the Casino Royale soundtrack [Classic Records/Colgems COSO 5005-45]. Accompanied by just a piano, I was almost persuaded that Bill Henderson was performing just for me in my music room. No, scratch that: Henderson wasn’t in my room, I was transported to the restaurant in which this was recorded! The occasional chink of wine glasses and other subtle aural clues reminded me that this was, in fact, just a recording. Similarly, on The Look of Love, Dusty was right there, albeit a little larger than life.
Much of the gear to which I have the pleasure of listening and reviewing sounds pretty good, especially in the hi-fi sense, but in my opinion it takes more than filling in a few check boxes on an aural checklist before a component can be considered as great. Not only must a great component cover all the usual hi-fi bases, it must connect listeners emotionally to the music. Kate Bush’s Wuthering Heights from her debut album, The Kick Inside [EMI EMC 3223], is a particular litmus test for me when I want to assess a component’s ability to convey emotion. Through the PH8, the emotion in Bush’s voice, the searing, mournful guitars, and the beautiful strings and piano literally sent shivers down my spine!
All of the preceding describes my experience with the PH8 when partnered with my SP9. When I had finished evaluating the LS17 SE on its own, I substituted it for my SP9 and verified my findings.
As impressive as it was when I listened to it with the PH8 and my SP9, listening to Equinoxe on the PH8/LS17 SE combo was an audio treat! The opening track of the second side, Part 5, has a huge, immersive sound stage, with the sound of the electronic instruments whizzing back and forth from left to right, and lots of little incidental sounds and effects to delight the listener. Details buried deep in the mix are easily revealed—mercilessly revealed might be a more apt way of putting it for lesser recordings.
Listening to The Great Gate of Kiev again, the bass drum whacks had a touch more weight and authority than when using my SP9. Ditto for when listening to Lieutenant Kije.
It’s not just the bass that improved when I substituted the LS17 SE for the SP9 in my system: treble clarity and sweetness, midrange bloom, air around the instruments, the palpability of the recording venue, the imaging, and the soundstage width and depth were all taken up a notch or two.
On Sheffield Lab’s direct-to-disc recording of Wagner’s Ride of the Valkyries [Sheffield Lab 7], the rasping from the brass instruments was particularly realistic, and the tintinnabulation from the triangle was crystal clear without any hint of being over etched or too bright.
For a change of pace I spun some jazz records next. First up was Analogue Productions’ excellent 45-RPM edition of The Oscar Peterson Trio’s We Get Requests [Analogue Productions V/V6-8606], specifically the opening track on side three, You Look Good to Me. The PH8/LS17 SE combo revealed numerous details, for example, when the music picks up the tempo after the beautiful intro you can really tell the bassist, Ray Brown, is enjoying himself by the sound of his humming which accompanies his playing!
As I listened to record after record, it became all too easy to forget that I was supposed to be listening critically rather than enjoying myself, so engrossed in the music as I was. In fact, for a few hours before sitting down to finish writing this review, I cranked up the volume and listened to a few of my old faves, including several 12” singles from synth-pop groups like ABC, The Human League, New Order, Trans-X, and Yazoo. Audiophile tendencies be damned, I was having fun, and at the end of the day, that is what this hobby of ours is all about, right?!
The Audio Research PH8 phono stage is very good sounding, very well made phono stage, and will be at home in systems comprised of the finest of ancillary components. The fact that is has easily adjustable input loading, a nifty tube hour meter (both available from your listening position via remote control, no less), and sufficient gain for all but the lowest output moving coil cartridges is icing on the cake. Yes, another input or two would’ve been nice, as would the addition of balanced outputs—but that’s where the PH8’s bigger brother, the Reference Phono 2 SE, comes in and I can’t wait to get my hands on one (and its matching line stage).
The PH8 earns my highest recommendation; if you’re considering a phono stage at or anywhere near this price level, the gentleman in the Doug Brady advert I mentioned in the opening paragraph of this review said it best: “You really must hear this”. As for me, I’ll be hanging on to the PH8 and LS17 SE for use as my references for as long as Audio Research will let me keep them!
Description Tube phono stage.
Frequency response ±0.2 dB of RIAA, 10 to 60 kHz; 3 dB points below 0.3 Hz and above 400 kHz.
Gain 58 dB at 1 kHz.
Distortion < 0.005% at 0.5 V RMS 1 kHz output.
Noise 0.2 μV equivalent input noise, IHF weighted, shorted input (74 dB below 1 mV 1 kHz input).
Input impedance 100, 200, 500, 1000 and 47K Ohms.
Input capacitance 200 pF.
Phono equalisation RIAA.
Output polarity Non-inverting.
Maximum input voltage 70 mV RMS @ 1 kHz (180 mV RMS at 10,000 Hz).
Tube complement Two 6H30s in the gain stage, 6550 and 6H30 as HV regulators.
Dimensions (whd) 470 mm x 132 mm x 305 mm.
Weight 6.8 kg.
Finishes Natural and black anodised aluminum.
Serial number of unit reviewed 31405802.
Warranty Three years non-transferable (90 days for tubes).
Audio Research Corporation
3900 Annapolis Lane North
Plymouth, MN 55447-5447
Analogue source Forsell Air Reference Mk 2 turntable and arm.
Phono cartridge Lyra Atlas.
Phono stage Allnic Audio Labs H-1200.
Preamps Audio Research SP9 Mk 2, Audio Research LS17 SE.
Power amplifiers PrimaLuna ProLogue Seven.
Speakers MartinLogan Spire.
Cables Phono: Nordost Frey. Interconnects: Nordost Frey. Speaker: Nordost Frey. AC: stock.
Accessories Target and SolidSteel equipment stands; Mission Isoplat; Furman Elite 15-PFi power conditioner; Audio Physic cartridge demagnetiser; Acoustech carbon fibre brush; Last record and stylus cleaning products; Audio Additives digital stylus force gauge; Spin Clean Record Washer Mk II.