Rogue Audio Atlas Magnum III Power Amplifier

One Hundred Watts of Pure Tube, Priced to Surprise

The Atlas Magnum III is the least expensive way into a real Rogue power amplifier, and Rogue designed it to punch above that. Ninety watts per channel of pure tube power, from four KT88 output tubes in push-pull.

It borrows its circuitry from Rogue's more advanced designs rather than being engineered down to a price. The signal paths are short, the noise design is careful, and the components are the precision parts you would expect further up the range.

An oversized linear power supply sits behind all of it, storing the energy that dynamic passages demand. That supply is usually the first thing cut from an affordable tube amp, and its absence is the first thing you hear when the music gets loud.

Inside the Chassis

An ultralinear and triode switch lets you choose the amp's character. Ultralinear gives you slam. Pure triode gives you the smoothness that tubes get bought for in the first place. The switch is on the back, so you can try both.

You also pick the transformer tap, 4 ohm or 8. Matching it to your speakers is what separates a tube amp that controls a speaker from one that merely drives it.

The tube complement is four KT88 output tubes with two 12AX7 and two 12AU7 in the small-signal stages. Bandwidth runs 20Hz to 30kHz. Slow-start turn-on sequencing protects the tubes, the board is heavy two-ounce copper, and the faceplate is machined aluminum. It measures 18 inches wide, 17 deep and 6.75 high.

Who Is This Amplifier Best For?

• You want real tube power on a budget — one hundred watts per channel from four KT88s is genuine tube power, not a small amplifier with a valve in the input stage for flavor.
• You want to choose your own sound — the ultralinear and triode switch changes the amplifier's character from the back panel, so you set it to your speakers and your ears after it arrives.
• Your speakers are a particular load — selectable 4 and 8 ohm taps let you match the output transformer, which is what keeps a tube amp controlled rather than merely loud.
• You are buying your first tube amplifier — slow-start sequencing protects the tubes at switch-on, and the KT88 is a current-production type that is straightforward to replace when the time comes.
• You do not own a preamplifier yet — the Atlas Magnum III is a power amplifier, with no volume control and no input switching. Pick a partner from our preamplifiers and the two make a system.

How Does It Connect to Your System?

Connect your preamplifier to the gold-plated RCA inputs. Speakers go to the gold-plated binding posts, on the 4 or 8 ohm taps depending on what your speakers present.

Pick ultralinear or triode on the switch, and let the slow-start sequence bring the tubes up. A full tube cage is available if the amplifier lives where it can be touched.

Pairs Well With

Here are some great companions:

• Preamplifier: Required, and the natural next decision — see our Preamplifiers.
• Speaker Cables: Match the output taps to your speakers — see our Speaker Cables.
• Interconnects: Quality RCA cables feed the amplifier — see our Interconnect Cables.
• Audio Rack: A tube amplifier wants air around it — see our Audio Racks.

Frequently Asked Questions

How much power does it make?

Ninety watts per channel, from four KT88 output tubes in push-pull.

What tubes does it use?

Four KT88 output tubes, with two 12AX7 and two 12AU7 in the small-signal stages.

What is the difference between ultralinear and triode?

Ultralinear gives you more power and grip. Pure triode gives you the smoothness tube amps are bought for. A switch selects between them.

Does it have balanced inputs?

Inputs are gold-plated RCA. Speaker connections are gold-plated binding posts with selectable 4 and 8 ohm taps.

Is a tube cage included?

A full tube cage and cover is available as an option, which is worth having if the amplifier sits where children or pets can reach it.

Where is it built, and what warranty does it carry?

Rogue designs and hand-builds it in Brodheadsville, Pennsylvania, with a 3-year limited warranty and 6 months on tubes.

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Learn More

Want to learn more about tube amplifiers, triode and ultralinear operation, or building a separates system? Visit our Learning Center for guides, tips, and expert advice.