Born in the U.S.A.: Rogue Audio Cronus Magnum amplifier

The Audiophiliac listens to one of the most affordable, fully featured American-made tube amplifiers you can buy.

Steve Guttenberg
Ex-movie theater projectionist Steve Guttenberg has also worked as a high-end audio salesman, and as a record producer. Steve currently reviews audio products for CNET and works as a freelance writer for Stereophile.
Steve Guttenberg
3 min read
The Rogue Audio Magnum amplifier Steve Guttenberg/CNET

A lot of audiophiles love tube amplifiers, and I've owned my share, but I don't currently have tubes in my main hi-fi system. I instantly remembered what I was missing when I hooked up the Rogue Audio Cronus Magnum integrated amplifier with my KEF LS50 speakers. They're good together.

Before founding Rogue Audio in 1996, Mark O'Brien worked for Bell Labs and other companies doing electronics development, lasers, and transformer design. Like so many audio designers I've met over the years, O'Brien started building amplifiers when he was a little kid. Audio is a lifelong journey for him, and while the fundamental principles of tube design were perfected years ago, it's only over the decades that he's learned the finer points of parts layout on the circuit board, and how that influences the sound.

Rogue uses mostly American-made internal parts like transformers, resistors and capacitors, the faceplate comes from Canada, and the rest of the chassis is made near the Rogue factory in Pennsylvania. The amp's power tubes will last 3,000 or more hours and the small tubes up to 10,000 hours; Rogue stocks all the necessary tubes, but tubes are readily available from many other sources. The tubes run hot, and if you have young children you can buy a "cage" cover to prevent small hands from touching them.

The 100-watt-per-channel stereo amp weighs 50 pounds, but when I unboxed the unit it felt heavier than that. It's also worth noting that the Cronus Magnum weighs twice as much as most 7x100-watt AV receivers. You also get a beautifully crafted, all-metal remote control for volume, but the ramp up/down is too fast. It's hard to set the exact level you want, so I usually walked over and set it by hand. Hey, it's high-end audio, and if I have to get up to tweak the volume every now and then, it's no big deal.

There are three line inputs, plus a phono input for turntables. If you have a subwoofer, hook it up to the amp's variable RCA outputs. There's also a headphone jack, but the headphone amp isn't tube-powered, it's solid-state. It sounded great with my Beyerdynamic T 90 headphones.

I can't say I heard any overt "tube" sound per se with the Cronos Magnum, it didn't add any warmth or midrange glow, but the LS50s got out of the way and let the music breathe. The notes are the same with all amps, but they can have a different feel with the music.

With a superb audiophile recording like Sera Una Noche's "La Segunda," the soundstage was huge, extending far beyond the LS50 speakers' locations. This recording of fusion/Argentinean music had a palpable presence, I felt like I could reach out and touch the bandoneon, guitars, cellos, clarinets, recorders, and so on. I could hear the acoustics of the recording venue. On "Taquito Militar," the hand percussion instruments' hard-hitting dynamics took my breath away. They sounded real!

The Cronus Magnum runs $2,295, but I will be getting a more affordable Rogue soon, the $1,295 Sphinx hybrid tube/digital amp. I only used the Cronus Magnum with my KEF LS50 speakers, but I'll listen more to this amp with a couple of speaker reviews coming up real soon. High-end gear like this is expensive, but it's built to last and sounds great for decades; today's AV receivers will probably be hopelessly out of date in five or six years.

Rogue Audio products are available here in the U.S. at its 60 dealers and throughout the world.