Rogue audio stereotube amplifier driver#

The output stage is coupled to the loudspeaker through an ultra-bandwidth output transformer, which provides both 4 and 8 ohm taps. Mark O'Brien says the KT77s have very nearly the midrange magic of E元4s and considerably better bass. The Atlas comes with KT77s, each individually biased, which means that when one wears out you don't need to replace the entire quartet.

Rogue audio stereotube amplifier driver#

Those two signals are then fed into a 12AU7 triode driver stage, which boosts the signal voltage to a high enough level to drive the output stage, which uses a pair of KT77 or E元4 tubes. A 12AX7 tube, configured as a paraphase inverter for the input stage, splits the signal and inverts half of it, thus creating a balanced signal pair. Its audio circuitry uses 1% metal-film resistors, ceramic tube sockets, and polypropylene coupling caps. The Atlas, part of Rogue's Titan line, is a two-channel, vacuum-tube, push-pull amplifier. The company also employs an architectural designer, Deborah Regh, to create the Rogue Audio look: sleek and streamlined, with slightly rounded, elegant edges. All Rogue units are hand-built, fully tested, burned in for 24 hours, then retested. They consider themselves more music lovers than audiophiles. Mark Walker, the operations manager, has a master's in mechanical engineering. Mark O'Brien, the president and primary electrical designer, has an advanced degree in physics. Rogue Audio has been building tube amps and preamps in Brodheadsville, Pennsylvania, since 1996. Or rather, maybe there was every bit as much as meets the eye, and more than the price tag suggests. Maybe there was more here than meets the eye. Then I reminded myself of my first reaction to this rock-solid slab called the Atlas-the cocked eyebrow, the whistle of surprise. I've finally joined Stereophile after all those years at The Abso!ute Sound, and this is how they welcome me? With a goddamned fourteen-hundred-dollar tube amp? I've got meter-long interconnects that cost more than that, Mr. Then (I'm not proud of this moment) I felt miffed. At 55 lbs and 55Wpc, that's about $25 per watt and per pound-bargain-basement for a tube amp. Then I called Rogue Audio and learned that it retails for $1395.

After examining its chassis of high-grade steel, its silver-anodized aluminum faceplate, its sleek and slightly rounded edges, and, above all, its two chunk-o'brick transformers-for such a little thing (a foot-and-a-half square by half-a-foot high), it's heavy-I guessed around five grand. When I unpacked the Rogue Audio Atlas, I didn't know how much it cost.