Salivating over tubes? Rogue Audio’s Cronus Magnum delivers a gourmet serving of hot tube goodness.
I put the disappearance of tube amplifiers during the 1960s, ‘70s, ‘80s and ‘90s down to laziness. That’s right, old-fashioned laziness.
You see, it’s far easier and fuss-free to batch engineer and fabricate rectangular black (or silver) boxes crammed full of things called transistors and toroidal transformers than it is to hand-wind a transformer with the correct values for a tube amp, and of course the tubes themselves have to be hand-inserted into the amplifier – causing more loss of profits.
That was obviously too difficult and time-consuming for the vast majority of audio companies manufacturing amplifiers, so out into the skip went all the tube bits and in came solid state – the pretender to the throne.
Maybe I am being a touch harsh; after all, there are plenty of excellent transistor-based amplifiers to rave about, but the wonder of tube audio practically flickered its way to oblivion during the rise of the solid-state machines.
Given the dominance of ‘conventional’ transistorised amps, the re-emergence of tube amplification is quite a stunning turn-around – but not unexpected, at least to this reviewer.
Luckily, the rise of the tube amp has attracted a few newcomers to these shores, the latest being USA brand Rogue Audio with its range of very tasty upmarket designs.
The company isn’t exactly a household name down in these parts but they have garnered quite a reputation for themselves since they burst onto the hi-fi scene back in 1996. To further underline their daring-do attitude to things, the company also runs Rogue Motorsports and have been busy racing a Suzuki SV650 in the Championship Cup Series in the States. Naturally, motorcycle racing and hi-fi music listening are perfect partners; sadly for me no one has seen fit to garnish me with a racing bike. Damn you, Rogue Audio!
Tom Davidson of Orange Road is the local importer/distributor, and he kindly loaned me Rogue’s Cronus Magnum integrated amplifier for an extended period. The Cronus Magnum is the pinnacle of the company’s Titan series, and features a raft of changes from the standard Cronus amplifier, including modifications to the power supply and other parts, and an exchange of output tubes from EL34s to KT90s – resulting in a hefty power increase from 55wpc to 90wpc. Having the Cronus Magnum for a month or so really allowed me to get to grips with the amp and assess its many virtues (and precious few vices).
The heavyweight aluminium front panel is kept simple with on/off, volume and balance knobs, and the source selector along with a headphone socket (a very good one I might add) and the ubiquitous remote sensor. It’s up top where all the action is: 4 x KT90 output tubes operate in push-pull mode, while 2 x 12AU7 Driver tubes, a pair of 12AX7 input and a single 12AU7 complete the package. 4 X single-ended RCA inputs include a decent moving magnet phono stage, while both fixed and variable preamp outputs allow flexibility (and the addition of a line-in only subwoofer if necessary).
It’s kick-ass heavy and will demand a serious amount of rack space, but once on the rack and cabled up I was ready for action – Rogue style. I used the following partnering equipment for the listening tests: Simaudio’s elegant Moon CD3.3 was the primary source (I also used its addressable on-board DAC for Squeezebox listening), with my Pro-Ject Studie turntable for vinyl replay. Speakers were Joseph Audio’s RM22XL’s (also reviewed on WD), while the cables used were Nordost Blue Heaven interconnect/Super Flatline MK2 Bi-wire speaker.
After cabling I allowed the amp to warm up before manually setting the bias of the output tubes. A simple 2-minute operation, the built-in meter and supplied Vishay bias tool made the job a breeze – once done it was down to brass tacks. I hurriedly ushered everyone out of the room, closed and locked the door behind me and settled in for the first of many listening sessions.
I decided to start with Tom Jones’ new Praise And Blame CD. This is a collection of mainly one-take recordings with an apparent dearth of Pro-Tools, and the Rogue/Moon/Joseph Audio system delivered the goods beautifully. Tom’s mega-voice was exquisitely reproduced, and not in a blustery, overblown way. Here was a singer delivering with passion and emotion, and just about as far as he can get from the Las Vegas showman we all know and love (well, some of us anyway). Guitar, bass and drums were all delivered with realism and excellent dynamic range, while the wrap-around sound staging really provided an immersive listening experience. I had the impression that the Cronus Magnum could easily rock out on heavier tracks, as it didn’t introduce harshness or flattening of dynamics even at higher sound levels.
Changing sources from CD to the Squeezebox Duet/Moon CD3.3 DAC, I selected an old favourite from the ‘80s – Japan’s Tin Drum. Listening to Sylvian, Karn & Co via the Rogue-based system was quite a treat; the Cronus Magnum did real justice to the breathtaking production values of this influential 1981 recording. Of particular note was its portrayal of drum and percussion; there was a real sense of stick on drum-skin that I’ve only heard with far costlier amplifiers and source gear. Remember, this was plain old redbook CD quality streamed audio from a beer-budget Squeezebox (albeit directed through the DAC of a $6K CD player).
Vinyl was next on the menu, and on to the Studie’s acrylic platter went Kraftwerk’s Tour De France on 180gsm. Using my Sumiko BPS on the 9-inch arm (high output M/C) proved fruitful; the phono section of the Cronus Magnum is extremely competent at reconstructing the info extracted from the groove. Bass was deep and tight and without excess flab or boom, while both voice and synth (yes – no trumpet or flugelhorn) were incisive and detailed. Compared with my 2-box phono stage (Trichord Dino) I did sense a slight upper-midrange hardening, but it was a great result nonetheless.
I’d like to use a gastronomic metaphor to sum up my experience with Rogue Audio’s superb Cronus Magnum. For a guy who has cooked and eaten juicy eye-fillet steak (sorry veg editors Gaz and Ash) and been incredibly happy doing so, it’s tantamount to being treated to a 300gm slab of prime Wagyu beef – superb and delicious, with mouth-watering quality that will be remembered long after it’s been digested.
Does the Cronus Magnum warrant 5 stars? You betcha it does. GARY PEARCE