Rogue Cronus Magnum MKII

Description

The Rogue Audio Cronus Magnum II is a classic example of the modern American tube integrated amplifier: substantial power, straightforward functionality, and traditional vacuum-tube circuitry combined into a single chassis. Hand-built in the United States, the Cronus Magnum II delivers 100 watts per channel from four KT120 output tubes, giving it considerably more drive capability than many conventional tube integrated amplifiers. Introduced as a substantially evolved version of the original Cronus Magnum, the MKII combines a triode preamplifier section with a power amplifier derived from Rogue’s Atlas Magnum design.

The amplifier’s four KT120 output tubes are complemented by two 12AX7 and three 12AU7 small-signal tubes. A large, high-storage linear power supply is central to the design, providing the current reserves needed for bass authority and dynamic swings. Rogue also uses short signal paths, precision components, and heavy two-ounce copper circuit boards in an effort to keep noise low while maintaining transparency. The amplifier provides both 4- and 8-ohm transformer taps, making speaker matching relatively straightforward.

One of the Cronus Magnum II’s most appealing characteristics is its versatility. Rather than being simply a power amplifier with a volume control, it includes an MM phono stage, three additional line-level inputs, a headphone amplifier, and buffered variable outputs that can be used with a powered subwoofer or for bi-amplification. The phono section offers approximately 44–45dB of gain, making it suitable for most moving-magnet cartridges and some high-output moving-coil designs.

The MKII also incorporates an unusually convenient manual-bias arrangement. An analog meter on the top panel allows the user to check each output tube individually, while Rogue supplies the necessary adjustment tool. A slow-start circuit helps protect the tubes during power-up. The amplifier’s exposed-tube appearance is unmistakably traditional, although Rogue offered an optional full tube cage for systems where additional protection was desirable.

Sonically, the Cronus Magnum II is notable for combining the dimensionality and tonal richness associated with tubes with a level of power and control that makes it considerably more versatile than the stereotypical low-powered tube amplifier. What Hi-Fi? described its presentation as “big and powerful”, noting its authority, wide-ranging dynamics, punch, and refined tonal balance. The publication also praised its bass grip and ability to remain composed with demanding music.

Enjoy the Music.com was similarly enthusiastic, calling the amplifier a “high-end audio” overachiever and praising its natural, authentic presentation, versatility, and robust construction. The reviewer particularly noted the absence of hum or buzz during testing and the amplifier’s ability to drive a wide variety of speakers.

Another review from audioFi emphasized the amplifier’s “lush tonal density”, lively musical character, and excellent MM phono stage. The reviewer also found that the amplifier maintained its character with both source components and less-efficient loudspeakers.

The Cronus Magnum II therefore occupies an interesting position in high-end audio. It offers the visual appeal and tube architecture enthusiasts expect, but its 100-watt output, substantial power supply, flexible connectivity, and strong speaker-driving ability make it a practical centerpiece for a serious two-channel system. For listeners who want tube character without accepting the limitations often associated with low-powered valve amplifiers, the Cronus Magnum II remains one of Rogue Audio’s most significant and recognizable designs.

Review Quotes

• “Big and powerful” with “wide ranging dynamics and plenty of punch.” — What Hi-Fi?
• “Lush tonal density with lively voicing” and “involving musicality.” — audioFi
• “High-end audio’s Poster Child for being an overachiever.” — Enjoy the Music.com

Product Specifications

• Type: Stereo vacuum-tube integrated amplifier
• Output power: 100 watts per channel
• Output tubes: 4 × KT120
• Preamp tubes: 2 × 12AX7, 3 × 12AU7
• Frequency response: 20 Hz–30 kHz
• Output transformer taps: 4 and 8 ohms
• Inputs: 4 RCA — MM phono + 3 line-level
• Phono gain: Approximately 44–45 dB
• Headphone amplifier: Built-in
• Outputs: Fixed and buffered variable outputs
• Other outputs: Suitable for powered subwoofer or bi-amping
• Power supply: High-storage linear supply
• Circuit boards: 2-ounce copper
• Controls: Input selector, balance, volume, mute
• Remote: Volume and mute
• Bias: Individual manual adjustment with top-panel meter
• Construction: Machined aluminum faceplate; hand-built in USA
• Dimensions: Approximately 18″ W × 17″ D × 5.5″ H
• Weight: Approximately 55 lbs. shipping weight