Karan Acoustics PH1 phono stage

The Karan Acoustics Phono Reference phono stage is one of the very best we have ever tested in the pages of Hi-Fi+. It is extremely quiet, is capable of being used with unfeasibly demanding cartridge loads, and has a useful set of alternate EQ curves for non-RIAA equalised recordings. However, these superlatives come at a price, in pounds sterling and avoirdupois: the Phono Reference is a heavy two-box design with a matching power supply that both weigh in at 27kg, and the complete deal costs just shy of £15,000.

Although until recently Karan also produced the one-box PH2 Mk 3 phono stage, but it was clear to chief designer Milan Karan that many of the elements that made the Phono Reference so good could be slimmed down into just the one chassis without making too many sacrifices on performance. The result is the new PH1 phono stage. Of course, the reality of designing such a device isn’t as easy as simply writing about it happening, but a surprising number of core elements are shared between the two designs, least of all a true differential (balanced) circuit approach.

The principle differences between the Phono Reference and PH1 (aside from the extra box, of course) is the Reference’s ‘unconstrained by price’ stance. The Phono Reference is a fully dual-mono, balanced design, featuring three sets of RCA and XLR inputs physically isolated from channel to channel across a whole PCB. Essentially, this makes three sets of paired mono RCA/XLR phono stage input banks with a common dual mono balanced and single-ended output stage. The PH1 has one RCA input and one balanced XLR input, each with their own balanced output stage. The other half of the board is given over to power supply, with three separate transformers (one for each channel and a third for the control circuitry). Neither section is as comprehensively specified as the Phono Reference, but that comes down to PCB real estate as much as anything.

In a way, the PH1’s ‘less is more’ approach might pay dividends for some turntable users: the Left and Right inputs for the Phono Reference are spaced across the whole of the rear panel, and this might be too long for some conjoined phono cables. The shorter gap between left and right channels makes the PH1 more user friendly. Those multi-arm users might bemoan having just the one input, but the rest of us will love the simplicity of the PH1’s connections.

What is completely retained from the Phono Reference is the near infinite range of cartridges you can use with the Karan PH1. The input load, capacitance, and gain settings can all be adjusted from a series of DIP switches on the circuit board. This is less convenient than the front panel dials of our reference Pass Labs XP25, which allows more of a ‘dial-in-to-taste’ control over the loading of a cartridge, but this is more of a ‘fit-and-forget’ adjustment as befits the once-per-cartridge matching process. Both ways have their merits – but the Karan has the advantage of not being prone to ‘readjustment’ by cats, children, cleaners, and the curious.

This near-infinitely configurable box is functionally identical to the bigger Karan. Take the top of the PH1 off, and you’ll be faced with two sets of five, four-pole DIP switches. These allow you to trim input capacitance from 50pF to 400pF, input impedance from 450Ω to 47kΩ, and gain from 48dB to 71dB; 48dB and 52dB for high-output cartridges, 64dB for medium output and 67dB to 71dB for lower-output designs. This means the PH1 can cope with any moving magnet, moving iron, and right up to the toughest of moving coil loads without fuss. I used it with the trusty, but aging, ‘cartridge in search of a load’ Ortofon MC 7500 – chosen because this is one of the toughest cartridge loads to get right, and normally requires a step up transformer. Only the very best phono stages manage this load without drowning in noise, and the Karan PH1 passes this test with its colours flying.

Once again, those using multiple cartridges on multiple arms will declare the Karan Phono Reference the better choice, because it allows different loadings to be set for each input. But that’s the price you pay for multi-source perfection. For the rest of us, losing a box and gaining a bank balance are about the only ‘sacrifices’ you’ll make in going for the Karan PH1. The two have identical specifications elsewhere. A quick turn of one of the two front panel knobs racks through a list of EQ curves: RIAA, EMI, Decca, Columbia, and Teldec. The argument over how important these curves actually are to collectors rages on, with lines drawn between an ‘idealist’ view of a near-immediate switch over to RIAA with the coming of stereo in the late 1950s, and the ‘realist’ counter argument that suggests EQ curves were changed at a more relaxed pace, which means records cut well into the 1960s (and beyond) might not all subscribe to the RIAA standard. How much of an issue this is depends largely on where you sit on this idealist-realist continuum, and how many LPs you own that were cut around half a century ago. It’s not a big thing for me, but your mileage may vary.

My take here was to ignore anything written about the KA Phono Reference and listen without prejudice. Only when I finished the review did I look back on Roy Gregory’s findings in issue 117, and at that point I realised two things: just how consistent Karan is with its phono stages, and just how close the PH1 gets to its bigger brother.

In fact, two words neatly sum up the Karan PH1: ‘consistent’ and ‘realistic’. The sound it makes is extremely realistic, a window on the recording process be that last week or 50 years hence. I’m still reeling from just how much information the re-released Queen box manages to put on the LP, and it’s helped by just how much information the PH1 manages to extract from the same. These Queen LPs are not necessarily my first choice in music listening, but the insight into the mix is so profound, one can’t help but be drawn in. The dynamic range especially was almost shocking, and you could hear Brian May and his sixpences as plectrums tear into a set of guitar strings causing his Vox AC30 amps to scream apart in beautiful, creamy-sounding pain. But that insight happened with every record, as befits a phono stage as consistent as the PH1.

In sonic terms, the Karan PH1 sits equidistant between my two favourite phono stages. It’s not as inviting-sounding as the Pass Labs XP25 and it’s not got the same ‘scrubbed clean’ detail as RCM Audio’s TheRIAA, but instead it walks between these two paths carefully and well. In a way, these three phono stages share a common trait of almost total cartridge load control, and all three benefit from getting the set-up absolutely right. It’s just when the PH1 gets all its ducks in a row, it has an ability to disappear from the system in an almost uncanny manner. You feel as if you are listening to the record without a phono stage impeding the process. Reading back RG’s test, I didn’t feel the PH1 had a ‘warm mid-hall balance’ but it retained the richness and harmonic structure of every recording, which makes me think it comes very close to the Phono Reference in sonic terms.

In fact, the PH1 is good enough to render the Phono Reference pointless. Except… in those rare shoot-for-the-moon systems where money is no object, where every turntable has many arms, and were the idea of ‘compromise’ is alien. At that point, the differences between the Phono Reference and the PH1 tip in the bigger phono stage’s favour. That doesn’t mean the Phono Reference is a device for ‘more money than sense’ users, it’s just that if you have a system of such magnitude, then the ‘no limits’ performance of the Phono Reference will be more in line than the ‘near as damn it no limits’ performance of the PH1.

Most of us, however, would be more than happy with the Karan Acoustics PH1 phono stage as an example of the best it’s possible to get from vinyl. Very highly recommended!

Technical Specifications

• Type: Solid-state phono-stage
• Inputs: 1pr balanced XLR; 1pr single-ended RCA
• Gain: 48dB – 71dB + one user definable setting
• Loading: 450Ω – 47 kΩ + two user definable settings
• Capacitive Loading: 50pF – 400pF
• Replay EQ: RIAA, EMI, Decca, Columbia, Teldec
• Absolute Phase: Switchable 0/180 degrees
• Outputs: 1pr balanced XLR; 1pr single-ended RCA
• Dimensions W×H×D: 50 × 11 × 39cm
• Weight: 18kg
• Price: £7,900

Manufacturer: Karan Acoustics

URL: www.karanacoustics.com

UK Distributor: Audiofreaks

Tel: +44 208 948 4153

URL: www.audiofreaks.co.uk

Back to reviews