One of the eternal diatribes within the audio (not just high-end audio) revolves around single vs. multi-chassis concepts and solutions. Adopted ‘common sense’ (that’s a bit of an assumption in some companies, but let’s run with it) suggests that separating the active audio signal circuits from their power supplies – and, in particular, the mains transformers and associated componentry – is a must for the best possible signal-to-noise ratio. It also means a purer, closer to perfection, signal being handed on to the next component in the chain. Some, however, say that while that may be all well and good, there is the other side of the coin (isn’t there always?) – what about additional connecting interfaces, connecting (umbilical) cables and the mutual EMF interactions between the two (or more) separate enclosures? Those advocating single-box solutions also have another argument to offer; by reminding the opposite camp about the old rule about the shortest path being the very best one.
Why not both?
Milan Karan of Karan Acoustics does not seem to be too bothered with either of the theories for one simple reason; he offers all his products in both configurations. And he has been doing so from the very early days of his work. So, his Master Collection designs offer both single and dual chassis options with all his preamplifiers, just as we have mono and stereo power amplifiers.
Leaving aside the indisputable fact that two boxes allow much more space to elaborate and improve on whatever would fit into just one, there is much more to consider and bear in mind even before any listening evaluations may have taken place. Which brings us to the very latest (and final) addition to the Karan Master Collection – the ‘simpler’ PHONOb single-chassis phono stage. Let’s start with the good news – compared to the flagship PHONOa (review in hi-fi+ issue 209), the PHONOb has the conceptually identical audio circuit and exactly the same range of adjustments for gain, input impedance and capacitance. Furthermore, the PHONOb has the same equalisation curve selection (RIAA, EMI, Decca, Teldec and Columbia), absolute polarity (phase) choice and can mute the main output accordingly.
The main difference in this area is that, instead of three inputs on the PHONOa, the PHONOb has just one single phono input (RCA and XLR) and one set of main outputs (also RCA and XLR). We should also bear in mind that, in Milan Karan’s vocabulary ‘one input’ means a complete phono preamplifier bar the initial stages of the mains-related power supply circuits. This is not a bad thing at all; if anything, this leaves more space in the single chassis for generously applied and well-executed regulation and other power supply electronics. PHONOb remains a true differential (balanced), dual-mono design and all the very best passive and active components remain present and follow the design principles of every product in the Master Collection Series.
A clear display and two large controllers left and right on the front panel is all you see on the elegant front panel. Also, the very best WBT (RCA) and Neutrik (XLR) connectors are used for inputs and outputs on the rear panel. Again, as on all other Master Collection products, Cardas Audio internal wiring and Critical Mass Systems supporting feet are present and correct.
Feet don’t fail me now
Setting up is as easy as it comes. It pays off to keep the PHONOb powered up at all times and not to listen seriously during the first 24 hours. Critical Mass Systems feet remain faithful to their mysteriously inexplicable (but most definitely positively working!) method of operation and will reward if the component is, once placed into position, left alone for a day or two before sounding at its best. It never ceases to amaze me how easy it is to hear the incremental improvements emanating from the CMS feet over a period of a couple of days before they settle into their final interpretation of any reproduced music.
As it comes from the factory, the PHONOb is set for a good all-round input impedance value of 660 Ohms (neither too low or too high) and one of the medium gain settings of 67dB (perfect for MC cartridges of 0.2-0.35mV output). We did not alter those settings during the review as those cartridges we used remained very faithful to their well established and known sonic signature as they were. To ensure as realistic results as possible the Master Collection LINEb line preamplifier was used in conjunction with the PHONOb. It’s fairly low gain, combined with the gain of the PHONOb added up in the best possible way, providing an extremely noiseless background and uncompressed musical dynamics at any volume output level.
Sonically speaking, Karan doesn’t put a foot wrong. You could extend that out to both phono stages, both preamplifiers, and both the stereo and mono chassis power amplifiers. They have the signal stealth of a cat-burglar and make some of the lightest impressions on the musical signal around; an absolute adherence to the signal to such an extent, you’ll hear any changes to turntable, arm, cartridge, cartridge tag, or cable long before the PHONOb makes its mark. And yet, this isn’t some analytical sounding system that exposes weaknesses elsewhere in the signal chain, it’s just incredibly musically cogent and lucid.
This works just as much with tracks you know supremely well that aren’t ‘test discs’ as it does for ones you use for analysis. Given the review cycled into place around the time of the death of Tom Verlaine, it was only right and proper to play ‘Prove It’ from Marquee Moon by Television [Elektra]. This is a hard and spiky sounding – yet truly influential and ultimately brilliant – piece of pre-punk history that isn’t the kind of recording that sits well with high-end hi-fi systems. However, through the PHONOb its sharpness and lo-fi background didn’t get in the way. In fact, it’s a fairly good indicator of just how well a system works beyond the well-manicured world of audiophillia; it often sounds better on less resolving equipment, but here the reverse is true; the honest approach of the PHONOb cuts through the glassy recording and the inherently raw nature of the track and lays it open for listening; the enjoyment is still retained in the music and the greater degree of analysis of that music.\
The more I played records through the PHONOb, the more records I wanted to play. The more albums I wanted to hear renewed and played through that astonishingly quiet background. Yes, some of that wanting to hear more is down to the extraordinary levels of detail and soundstage retreival it has, and that detail – along with the even more poweful dynamic range – are the only notable concessions the PHONOb gives to its bigger brother.
It’s time to face the two-box elephant in the room; the Master Reference PHONOa. Just how much better is the two-box phono stage? OK, so there’s the three inputs that make the PHONOa more of a sensible solution for someone with multiple tonearms. But in terms of outright sound quality, the PHONOb is extremely impressive delivering close to 85% of the sonic performance of the PHONOa, giving that last scintilla of detail, dynamic range, and transparency to its bigger brother. In fact, by pulling back from the near ‘information overload’ of the PHONOa, the PHONOb is a phono stage better suited for long-haul listening. Given that’s the PHONOa we’re talking about, the PHONOb is far removed from a ‘stripped down’ model.
To have one world-class phono stage in your line up is rare; to have two is exceptional, and the Karan Acoustics Master Reference PHONOb is truly exceptional.
- Type Solid-state phono stage
- Inputs 1× balanced XLR; 1× single-ended RCA; All independently configurable
- 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 500 × 110 × 390mm
- Weight (combined) 22kg
- Price £24,995
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