Audio Research PH8 Phono Stage (Hi-Fi+)

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Audio Research PH8 Phono Stage
Audio Research PH8 Phono Stage (Hi-Fi+)

With so many reasonably-priced phono stages reaching a pretty high standard, is it really necessary to spend this much on Audio Research’s PH8? Sadly, the answer is – yes…

I don’t know about you, but if I was stumping up this sort of dosh for a phono stage I’d want (nay, demand) something downright amazing with absolutely knock-out orgasmic sonics from the first moment you hear it.

I’d want to be blown-away by a sound that is clearly superior to what I already have. The improvement would have to be blindingly obvious; not something you have to listen carefully for, but an obvious immediate gain in performance.

But is that a realistic expectation – even given the massive price tag of the PH8? Sure, the PH8 is bound to be good; it’s from ARC – ‘nuff said. But doesn’t the law of diminishing returns apply with a vengeance to products like this?

Maybe all one should expect is a subtle improvement over a good but more realistically-priced phono stage. Yeah – right! Such were the thoughts that ran through my head as I got the PH8 ready to roll, removing the top to fit the tubes.

Affordable? Well, sort of

Actually, to keep things in perspective, it needs to be said that the PH8 is not the best phono stage Audio Research make. That honour goes to ARC’s Reference 2. The PH8 is intended as a more affordable version of the latter.

Of course, the term ‘affordable’ is used here in its relative and comparative sense. The PH8 remains an extremely costly piece of kit, and will probably be beyond reach for many enthusiasts. But, it’s still an exciting and interesting product!

It borrows some of the Reference 2’s technology, but features solid-state J-Fet input devices rather than the four 6922 tubes used in the Reference. Coupling cap types and circuit board material are common to both products.

Straight from the box, Audio Research warn that a long burn-in period is required before new equipment sounds at its best. Our review PH8 already had a few miles on the clock, and proved to be immediately impressive.

In typical ARC style, the PH8 produces a big, rich, deep sound that has massive scale and depth. It’s a very solid tactile sort of presentation – there’s nothing ‘small’ or effete about the sound. The music sounds focused and very ‘present’.

The PH8 has a fixed gain of 58dB. Overload point is a massive 70mV at 1kHz, making it suitable for virtually any pickup on the market - fixed or moving coil. We used a Koetsu Urushi Sky Blue; a medium/high output MC pickup.

There was plenty of level, and background noise was very low. Those with ARC preamps (like the LS-27) would be able to vary the gain of the line input stage to create a comfortable listening volume.

In order to tailor the phono stage to your cartridge, the PH8 offers variable input impedance. When using fixed-coil (MM) cartridges, you’d need to set the impedance to 47k Ohms. But MC cartridges can be used at any impedance.

Frisky

The 47k Ohms setting should deliver the brightest liveliest sound, but if the top-end is a bit too frisky selecting a lower impedance should help, meaning you can fine-tune things to get the best results from your chosen pickup.

A stereo/mono switch is provided – very important for those who play old mono LPs. Switching to mono cancels output caused by vertical motion of the stylus, and has the effect of significantly reducing pressing rumble and noise.

The PH8 is very revealing, yet not in a destructive manner. It always makes the most of whatever signal you feed it with, so you hear what’s right with your recordings, rather than having the bad things emphasised. Here’s an example…

While comparing a couple of high-end turntables using another phono stage, we noticed that one of the decks clearly revealed that two guitars were playing at a certain point in a track. With the other (lesser) turntable, this detail wasn’t quite so obvious.

However, with the PH8 in the driving seat, you could clearly hear two guitars being used with both turntables. In a sense, the PH8 almost reduced the difference between the two decks, making both sound utterly fabulous.

For years now, we’ve had it drummed into us that the source component is dominant, holding the key to superior sound quality. Yet the extra ‘something’ delivered by the PH8 almost made the absolute quality of the turntable seem less crucial.

 

Turntables? Who needs ‘em!

This represents something of a paradox. I’m not saying you can use any old turntable with the PH8; a chain is only as good as its weakest link. But the need for the front-end to shoulder the full burden of responsibility is much reduced.

Tonally, the PH8 delivers a fairly rich warm sort of sound; full-bodied and weighty. Detail is amazing, but never in the sense of it seeming ‘etched’ or forced. Things sound smooth, natural, and impressively holographic.

Bass is solid and powerful; the mid-band open and liquid; the highs brilliant and incisive, but sweet. Best of all, there’s an impressive three-dimensional ‘out of the boxes’ soundstage that suggests real depth and space.

Bandwidth is unusually wide, with -3dB points below 3Hz and above 400kHz. On paper, this makes the PH8 potentially sensitive to sub-sonic noise and rumble. However, in practise there should be no issues given a good turntable.

Distortion levels are extremely low, and gain is a useful 58 dB, making the PH8 is sufficiently sensitive for use with low output moving coil cartridges. You could even use an MC step-up transformer without risk of overload.

Bring on the Billington.

I had a Billington MC transformer to hand, and tried it with impressive results. With most MC phono stages, you would not be able to use a step-up transformer due to problems with impedance and overload. But, with the PH8, it worked well.

We got a much bigger soundstage, with greater ‘scale’ and wider dynamic contrasts. The sound had enhanced depth, and much-increased presence. Even at a low setting of the volume control, the sound effortlessly filled the room.

The inputs and outputs on the PH8 are single-ended, with variable impedance loading (47K, 1K, 500, 200, 100 ohms), plus Stereo/Mono, and Mute buttons. A choice of silver or black front panels is offered.

The vacuum-fluorescent display offers eight selectable brightness levels. The display can be switched off, but nine small pixels remain dimly lit so you know your PH8 is still powered-up.

Usefully, all these functions are accessible via the supplied remote control, so changes can be made from your listening chair. There’s even a tube meter, so you know how long the valves have been in service.

While the Reference 2 might deliver even better sound quality, the PH8 gets quite close to its more expensive sibling. Near enough, perhaps, for many to consider the difference in price to be too high to justify in terms of the improvement offered.

Certainly, when coupled with a good turntable/arm/cartridge, the PH8 makes listening to vinyl hugely rewarding. No matter how good your digital source (CD, SACD, or hard-drive) might be, LPs still offer a certain extra ‘something’.

EAT to the Beat.

Using the impressive EAT Forte-S as our front-end, the PH8 created a big solid richly-detailed sound that was notable for its spacious dimensionality and tonal opulence. Dynamic range was wide, and the music emerged from an inky-black silence.

It was akin to listen to CD, in so far as there was no audible surface noise or background hiss. At the same time, the music sounded freer and more natural than CD, with a wider range of tone colours and greater subtlety.

Timing seemed better too, so that rhythms were more tightly sprung with greater forward momentum. Put simply, the music (and performance) sounded truer and more real – as though you were listening to real people playing live.

The PH8 is a fabulous phono stage in every sense; incredibly good sonically, and hugely aspirational. It’s such a pity the cost is so high, since it means only a lucky few will ever get to own such an amazing price of kit. Life is so unfair.

But, if you can afford the asking price, definitely go and audition a PH8. We think it will significantly improve on your existing phono stage, almost irrespective of what it is and what it costs, and (probably) leave you amazed and impressed.

The way it brings your vinyl to life is incredible. You’ll go through your collection hearing old favourites as never before, which is great. Only trouble is, you may not fancy listening to CD afterwards! There had to be a downside…

Technical Specifications

Type: Tube/Transistor phono stage for MM/MC pickups
Origin: US designed and made.
Features: One set of unbalanced inputs. One set of unbalanced outputs. Stereo/mono switch. Variable cartridge loading. Mute button
Frequency response: ± .2dB of RIAA, 10Hz to 60kHz; 3dB points below 0.3Hz and above 400kHz.
Distortion: Less than .005% at .50V RMS 1kHz output. GAIN: 58dB at 1kHz (MC & MM compatible).
Push buttons: Power, Mono, Load, Mute.
Input impedance: Selectable 47K, 1000, 500, 200, or 100 ohms with 200pF Unbalanced.
Output impedance: 200 ohms Unbalanced. Recommended load 50K-100K ohms and 100pF. (10K ohms minimum and 2000pF maximum.)
Output polarity: Non-Inverting.
Maximum inputs: 70mV RMS at 1kHz (180mV RMS at 10kHz).
Rated outputs: .50V RMS 10Hz to 60kHz, 100K ohm load (output capability is 50V RMS output at 1/2% THD at 1kHz).
Power supplies: Electronically-regulated low and high voltage supplies. Line regulation better than .01%.
Noise: 0.2uV equivalent input noise, IHF weighted, shorted input (74 dB below 1mV 1kHz input).
Tube complement: (2) 6H30 dual triodes with JFET input. 6550 and 6H30 as HV regulators.
Dimensions (WxHxD): 47x13.2x30.5 cm D. Rear chassis fittings extend 1.5 cm.
Weight: 6.8 kg Net; 10.5 kg Shipping.
Price: £6,299

Manufactured by: Audio Research Corporation
URL: www.audioresearch.com

Distributed by: Absolute Sounds
Tel: +44(0)20 8971 3909
URL:www.absolutesounds.com

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