Rogue Audio Stereo 100 Power Amplifier

Just When You Thought You Knew What It Was All About


Francis Vale


In the beginning, thus was the big bang. In one incomprehensible instant all the stuff that became our universe burst into existence, rapidly occupying that newly available space-time faster than a rent controlled apartment in Brooklyn Heights. An incomprehensible billions of galaxies, each with billions of unknowable stars gushed forth from a pinpoint in space tinier than a pore on a shiny peach.

Weird things happen when so much matter is condensed into a fractional space, like at the big bang. In those tiny fractions live a whole bizarro universe of quantum mechanics. For example, there is a phenomenon called quantum entanglement, which essentially means that pairs or groups of infinitesimally small particles share knowledge of each others state. At that very crack of an instant, pairs of atoms or subatomic particles like electrons may have hooked up before each said adios to the other and book’d it for vast reaches unknown.

After that almighty bang, even after these quantum entangled particles got spread out and separated from each other by millions of light years, they still seem to “know” what the other half of the pair is up to, like your suspicious partner.

We are all made of the same stuff that comprises the universe. So because of that big badaboom it is possible that an electron or two of your body is quantum entangled with the electrons of someone (or something) else living a life on a planet in a galaxy far, far away. On Earth, you maybe scratch an electron on your nose and its state flips upside down. Its entangled electron partner at the opposite end of the galaxy immediately flips right side up. A tickle felt across the universe.

I say all this in passing because of this review of the Rogue Audio Stereo 100 tube amplifier. In this instance, the electrons travel not to the farthest galactic reaches, but are shuttled to and fro within an octet of glowing glass. Within this amp’s black metal shroud lies a deep mystery of why this back and forth quanta of subatomic particles should give such pleasure.

The electrical journey starts with a transformer-coupled input stage from a company by name of Jensen. M. Jensen spirals around the electrons like a multi-coiled python in search a meal, but, he, being a passive and well balanced beast, transfers the energy on to another circuit, a 12AX7 tube voltage amplifier. That slightly amp’d juice is then pushed on to a 12 AU7 driver tube. Each of the stereo channels has its own separate pair of these small-signal Euro tubes. Then at last arrive the big guns; four mighty glass bottles worth of KT120’s wrap their ravenous glowing arms around that minimal morsel of audio signal.

These massaged rivulets and streams of audio signals now need something to propel them forth to your speakers. In all amps, you are in fact listening to their power supplies. The Stereo 100 has five in number, each hefty and distinct, and no doubt copiously contributing to its 60 lb (27.2kg) weight. The Rogue’s filtering scheme also tamps down those remaining variations of DC voltage that might ruffle your discerning ear whiskers. The amp’s two high-voltage supplies store this meaty juice in its capacious electrolytic capacitors. The entire energetic caboodle is bypassed by high-quality film capacitors. The final result is that the glass modulated electrons river along from the power supplies with a submarine silent noise floor. The Stereo 100 sends out two switch selectable gushers of watts; one an ultralinear stream cascading out at 100Wpc, the other a triode coursing along at 60Wpc.

If you are intrinsically biased against manually adjusting the standing current for each of the KT120 bottles, put it aside, as there is no auto-bias capability in the Rogue. And while you are so manually biasing about every four months it also could become an opportunity to be thinking about adjusting any implicit biases, heaven forbid.

As for the Rogue Stereo 100’s sound, like all things audiophile, much depends on what you may have done already to your poor system. Still, I can say this much. The Rogue really likes some interconnects going from preamp to amp better than others. If you want the full OMG scenario, use the Stereo 100’s balanced inputs. Rogue went way out of its way to properly couple the internally balanced signal, with the intent that RCA single ended inputs get the same low noise treatment as balanced. Nah. For the intrepid the balanced inputs offer more than low noise, far more.

When I plugged in a pair of Audience Au 24 SX XLR interconnects ($2,400 for a 1m pair) things went from a really nice RCA pony to a balanced stallion that kicked down the barn door and never looked back. The dynamics blew up. The music was now driven to perform. On a very big stage. You can dig your spurs into the RCA’s sides as hard as you want, but they simply can’t win this get up and go race.

Sure, $2,400 is a lot of scratch, almost 70% of the Stereo 100’s $3495 price. But if you consider that this $6,000 combo will easily go up against amps costing $10K and up, not such a bad deal.

But, this being a reasonably priced amp appealing to audiophiles who want the big high end experience without the big bucks, I went through a bunch of different RCA interconnects, using that XLR quality sound as the benchmark goal.

Oddly enough, it was the Nordost Red Dawn interconnects, costing about $500 or so per 1M pair that won the day. These were not the latest and greatest versions, either. The Red Dawns, in this particular gear configuration (Schiit Freya + preamp to Stereo 100), trounced all the other RCA wires I tried, some costing many thousands. You could live with this $4,000 Stereo 100/Red Dawn setup very happily evermore.

Why should interconnect wires even matter? Who TF knows. I do know from experience that the Red Dawns show a native capability to pass a lot of signal, whatever that means. At a more fundamental level, why should electrons change the nature of the sound? It’s not as if there are round electrons, square electrons, or chocolate fudge-shaped electrons.

Electrons, being at the quantum level, are inherently indeterminate. They live a life as a fuzzy wave function, neither here nor there. But when observed, its fuzzy state snaps to a definite one. Don’t look at, and who knows what its state is, up, down, or whatever. (So how do you read the final result of a quantum computation without upsetting the quasi apple cart. Answer: very carefully. )

The electron creates the electromagnetic force of magnetism and electric force that provides electricity to power motors and all electrical devices. But electrons also create photons and visible light.

So now you want to tell me that these daft and woolly creatures can be tamed into an invariably constant audio signal? Simply put, these are totally wazoo beasts that are more than just keenly attuned to their environment. In being shaped by it, they also shape it. Perhaps this explains why interconnects and speaker wires (plus circuits, tubes, transistors, etc.) with different physical properties alter the sound you are hearing; sometimes right in from of your nose, and maybe, sometimes a million light years away.

Or just maybe, it’s just all about you, which you always knew, anyway.

This, of course, would mean that all reviews of high end audio gear are exquisitely solipsistic. Which may explain why I much preferred ultralinear mode of the Stereo 100 over triode. But twas not always thus. In the beginning I preferred triode.

On a whim, after about 100 hours of use, I switched over to ultralinear. Now that was different. Triode now sounded a little too warm, too obviously rounded, and a bit squishy lip smacking, like that aunt you avoid at holiday dinners. This preference was only reinforced when I used the XLR inputs of the Rogue. Maybe triode gets a start up pass while ultralinear has to work harder, longer, to get some respect.

The Stereo 100 is also very un-tube like, which may piss of all that internal glass: so tell us again, why we are here, exactly? The Stereo 100 controls the bass line with a mighty mitt, something only amps of a solid state persuasion are supposed to be capable of. This Rogue’s highs are also as clear as a wannabe saint’s desire to be canonized. And its mids, well, these are tubes, remember? Not just there, there, but also no need to rewind to figure out what the hell did he/she/they just say? In other words, the Rogue Stereo 100 is a tube amp that’s not a tube amp that’s not a transistor amp.

So, what is it exactly?

It’s what you want.




21st, The VXM Network,