The Rogue Audio Chronus Integrated Amplifier and Stealth Phono-Stage

Back in Issue 40 I reviewed Rogue Audio’s fascinating take on the budget valve recipe, the Metis pre-amp and Atlas power amp: fascinating because in this day age most budget valve designs are built in the China (the Rogues hail from Pennsylvania); fascinating too, for the compromises chosen and the clever engineering solutions adopted to maximize performance. At a total cost of £2385, it was a winning combination.

two capacitive loadings, four gain settings and four different resistive loads. It’s a well chosen spread, embracing both MM and MC cartridges, one that will repay careful selection of not just loading but also the gain, matching the cartridge to the sensitivity and overall gain of the system. (See the phono-stage group test on page 28 for much, much more on this). In comparison the Chronus integrated amp seems straight-forward; three lineinputs and a MM phonostage, a balance control and remote volume. There aren’t even different output terminals for the loudspeakers (impedance being hard-wired internally for 4 or 8 Ohms) although there is a headphone output! Well, don’t be fooled. This is a fixed bias amp – meaning (perversely) that you have to adjust it. Fortunately this is easily done, using the tool supplied, the meter fitted into the top-plate and the four toggleswitches and trim-pots hidden under the hatch just behind the right-hand output tubes. The instructions are clear and easy to follow and it’s important that you do, because the correct bias on the power tubes maximizes both their output and their sense of musical grip, helping explain the 55 Watt rated output. Otherwise, set-up is straightforward; pay attention to the supporting surface to reduce microphony and decide whether you want to use the supplied valve cage or not (in the absence of kids and kittens I didn’t).

One thing I really liked about the Atlas power amp was its substantial mains supply, a much larger transformer than you expect being bolted straight to the chassis base-plate, reducing the unit’s visual bulk. The Chronus employs exactly the same arrangement as well as the two pairs of EL34 output tubes. These might lack the power and bottomend grunt of 6550s, but their mid-band is legendary and for products at this price that’s what counts. Hooked up to either the Eben X-Babies or the Spendor SA1’s the Chronus produced a sound that was warm, sweet and intimate but never sluggish. Eliza Gilkyson’s ‘Separated’ never lags despite its measured pace, its natural sense of contained restraint. The stately bass-line and subtle drum-work is a joy, perfectly underpinning the fragile beauty of the lyric. And that voice; the Rogue has just the right, slightly husky quality that separates Gilkyson from so many of her “sweet but bland” peers. Let the disc run and the tempo picks up perfectly, but once again it’s the pain and anguish in the vocal that carries the ‘Ballad Of Yvonne Johnson’. Music is delivered with an enticing warmth that draws you in, providing long-term, fatigue-free listening no matter how frenetic the material, how pro-tools glassy the recording.

Moving up in resolution to SACD and Eleanor McEvoy’s Love Must Be Tough and you confirm that the subtle rounding and smoothing that you’ve got used to with CD is the amp and not the recordings. This is not a high-definition device, with both transparency and resolution limited in absolute terms.

But fear not, what’s much more important is that the colours are right and the notes are in the right place – things that leaner, meaner, cleaner designs at this sort of price so often get wrong. So the jaunty clip of ‘Easy In Love’ retains all its infectious enthusiasm, even when things evolve from the almost simplistic opening into the far busier and more congested finale. And, as well as that sense of unforced momentum, you get the full range of instrumental colours, a factor that separates instruments tonally where more sterile amps rely on doing so spatially. Large-scale orchestral works might lack really well defined acoustic boundaries (hardly a surprise given the price of the Chronus) but they definitely have a satisfying spread and sense of scale.

Well now we have another two-box Rogue Audio pairing vying for your budget buck, but this time round the physical split is rather different. Designer Mark O’Brien has combined what amounts to an Atlas and a Metis into a single box, at the expense of a simplified pre-amp power supply. The up-side is the cost saving that comes from losing the second chassis. You even still get the built in MM phono-stage for those who want access to occasional vinyl usage. The end result is a cut in price to £1600, a figure that leaves room for a lot of extra discs – or just enough space in the budget for a separate, standalone phono-stage for those who want to take record replay rather more seriously – which brings us to the Stealth phonostage. Housed in the simplest of chassis work, Rogue’s budget phono option is priced at £695 and does rather hide its light under a bushel. Derived from the excellent MM/MC stage that’s built into the Company’s 99 pre-amp, the Stealth is a solid-state unit that offers user adjustable gain, capacitive and resistive loading via dip-switches located on the main circuit board. You need to remove the lid to reach them so make sure the power is off before making any adjustments! Add to the performance we heard and liked so much in the 99 the benefits of a dedicated chassis and power supply and not surprisingly, the Stealth is impressive indeed.