Anthem STR Power Amplifier
The Anthem STR Power Amplifier marries earth-shaking bass control with majestic dynamics, keeping orchestral climaxes and film soundtracks powerful, tight, and finely detailed. Home Theater Review found its blend of musicality, clarity, and finesse exceptional for a high-current Class AB design, while the beautifully machined chassis and 400W-per-channel output complete a seriously capable stereo centerpiece.
WATT RECOMMENDS
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Deliciously Crispy
Sound Quality
92/100
Build Quality
90/100
Value for Money
92/100
Pros
Combines exceptionally powerful, tightly controlled bass with rare detail and finesse for the category.
Delivers convincing large-scale orchestral dynamics and remains composed with demanding movie soundtracks.
Worked successfully with every speaker pair the reviewer used and has a beautifully machined chassis.
Considered a rock-solid value despite its premium price, with performance that bridges power and refinement.
Cons
Premium pricing means it is not an entry-level stereo power amplifier.
WATT RECOMMENDS
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What Reviewers Are Saying
SOUND QUALITY PERFORMANCE 92/100
The supplied review portrays the STR as an unusually complete high-power Class AB amplifier: immensely forceful and controlled in the bass, yet clear, musical, and refined. It was especially persuasive with demanding orchestral and soundtrack material; spatial performance is discussed less directly.
Transparency Resolution
94/100
Home Theater Review heard bass detail and tightness that it seldom encounters from amplifiers below $10,000. The reviewer also specifically credits the STR with clarity and finesse alongside its large-scale power.
Tonal Balance Musicality
94/100
The review finds that the STR does not trade musicality for brute force, praising its combination of musicality, clarity, and finesse. Its overall presentation was considered among the best Class AB amplification the reviewer had experienced, regardless of price.
Dynamics
96/100
The STR delivered earth-shaking bass power while retaining tight control, and it remained convincing when pushed hard with demanding film soundtracks. Full-power orchestral passages were described as majestic, with the scale, dynamics, and complexity fully intact.
Soundstage Imaging
84/100
The review praises the scale and complexity of large orchestral presentation, which suggests a convincing sense of musical organization under demanding conditions. It offers little direct comment on image placement, stage width, depth, or layering.
Assessments of Build Quality, Usability, and Overall Propositions.
Build Quality
90/100
The reviewer calls the chassis beautifully machined. The STR is also a substantial 60-pound stereo amplifier specified for 400W per channel into 8 ohms, 600W into 4 ohms, and brief 800W peaks into 2 ohms, indicating a serious high-current implementation.
Value for Money
92/100
At roughly $6,500-$6,900 currently, the STR remains a premium-priced power amplifier, and the review similarly noted its original $5,999 price was not entry level. Even so, Home Theater Review called it a rock-solid value, particularly given its bass authority, refinement, and performance against amplifiers under $10,000.
Reviews & Sources
Professional reviews and sources for this product's Watt'n Potatoes analysis.
Online Reviews & Mentions
YouTube Reviews
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Specifications
- Impedance
- 8Ω 4Ω 2Ω
- Power Output (per channel)
- 400 W 600 W 800 W*
- Specification
- * Maximum 3 seconds due to high current draw.
- THD (400 W)
- 0.0007% (1 kHz), 0.004% (20 kHz)
- ITU-R (19 kHz + 20 kHz)
- 0.0006%
- SMPTE (60 Hz + 7 kHz)
- 0.0016%
- SNR (IEC-A, ref. 400 W)
- 121 dB
- Frequency Response (20 Hz - 20 kHz)
- ± 0.1 dB
- Power Bandwidth (-3 dB at 400 W into 8 ohms)
- 91 kHz
- Slew Rate
- 30 V/μs
- Damping Factor (20 Hz - 1 kHz)
- 360
- Channel Separation
- 101 dB (100 Hz), 98 dB (10 kHz)
- Input Impedance
- 10kΩ (RCA), 15kΩ (XLR)
- Input Sensitivity (for 400W into 8Ω)
- 2.1 Vrms
- Voltage Gain
- 29 dB
- 120 V version
- In countries where the line voltage is 120 V, this product operates from a single phase AC power source that supplies between 108 V and 132 V at a frequency of 60 Hz.
- 220-240 V version
- In countries where the line voltage is 220, 230, or 240 V, this product operates from a single phase AC power source that supplies between 198 V and 264 V at a frequency of 50 Hz.
- Standby
- 310 mW
- Idle
- 65 W
- Typical Playback Levels
- 150 W - 300 W
- High Playback Levels
- 600 W - 1100 W
- Height
- 6-3/4” (17.2 cm)
- Width
- 17” (43.2 cm)
- Depth (not including power cord)
- 18-1/2” (47 cm)
- Weight (unpacked)
- 60 lb (27.3 kg)
Manufacturer's Description — Anthem
STR Power Amplifier pictured with STR Preamplifier (sold separately). Both models available in black or silver finishes.
Two-Channel Revolution.
The STR Power Amplifier is the beating heart of a world-class 2-channel sound system. It delivers massive power generation, with audiophile-quality output in a smartly designed component.
Designed, engineered, and Crafted in Canada, the STR Power Amplifier delivers 400 Watts/channel into 8 ohms with both channels driven, a massive 600 Watts/channel into 4 ohms (both channels driven) and 800W in 2 ohms, for true no-holds-barred performance.
Inside, the STR Power Amplifier uses two colossal transformers and multiple high-current output devices so the most subtle details and dynamic peaks are handled equally well. Outside, its beautifully designed cosmetics, including a 7-inch graphic control display and secure, highly conductive audiophile connectors provide a perfect match to the STR Preamplifier.
- 400W/600W/800W into 8/4/2 ohms
- Cascoded complementary feedback input stage
- Sixteen bipolar output devices per channel
- Dual Mono Design
- Massive toroidal transformers
- Soft turn-on
- Four power on/off options
- No rail fuses
- Advanced Load Monitoring™ Technology
- Graphic front panel display for the power meter, status, and easy setup navigation
- Available in Silver and Black Finishes
- Crafted in Canada
Massive Power.
Cascoded Complementary Feedback Input Stage
The STR Power Amplifier benefits from our proprietary input topology—a unique departure from the classic differential input stage. Eight low-noise bipolar input devices are configured in a complementary active-load cascoded feedback arrangement for reduced distortion, exceptionally linear response and superior bandwidth. Transistors in critical stages are hand-selected and matched for lowest possible distortion.
Sixteen Bipolar Output Devices Per Channel
Anthem engineers incorporated sixteen bipolar output devices per channel, resulting in peak production that is effortless and instantaneous, cinching even the most challenging material. The use of multiple bipolar output devices in class AB configuration also dramatically reduces distortion while ensuring extreme linearity, extensive bandwidth, and stress-free reliability.
Experience the immense dynamics of up to 800 clean watts delivered into demanding 2-ohm loads, or 400W into 8 ohms/600W into 4 ohms continuously and with both channels driven.
Massive Toroidal Transformers
Conservatively rated, in a low-profile design shaped to minimize hum, the low-impedance toroidal power transformers — one for each channel — make no sacrifices when it comes to delivering a continuous supply of pure, clean, low noise power. As well, both the power supply impedance and internal cabling inductance are minimized to deliver a clear path for maximum power.
The amplifier channels are thus able to deliver stable, continuous power at maximum output without affecting one another, even when driving the lowest impedances. While some amplifiers oscillate or run out of power when driving lower impedance loads, the STR Power Amplifier remains perfectly stable under all conditions.
Soft Turn-On
A sequence-controlled soft turn-on significantly reduces power line transients and in-rush current during start up, thereby preventing accidental tripping of circuit breakers.
No Rail Fuses
The amplifier sections are Direct Connected to the power supply capacitor bank. This keeps output impedance remarkably low while making more power available to the amplifier. Even when driving lower or complex impedance loads, the result is audibly superior performance.
Power On/Off Options
In addition to the traditional options for power-on, the STR Power Amplifier allows trigger mode and audio signal sensing to be combined so you would never need to think about turning the amplifier on or off manually. This can be useful when using a preamp with Home Theater Bypass mode together with a surround sound processor in the same system.
The Crafted in Canada Difference
The STR Power Amplifier is designed, engineered and manufactured in Canada and is part of premium STR Series by Anthem, the leader in audio power and control.
Verified Dealers
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Authorized dealers for Anthem STR Power Amplifier
- Ahead Stereo — in-store — Los Angeles, California, United States (website)
- Alpha High End — online and in-store — Brasschaat, Vlaams Gewest, Belgium (website)
- Alta Fedelta — online and in-store — Lombardia, Italy (website)
- Analogue Seduction — online and in-store — Whittlesey, England, United Kingdom (website)
- Archer High Fidelity — in-store — Washington, Virginia, United States (website)
- Arctic Audio — in-store — Fargo, North Dakota, United States (website)
- Audio Advice — online and in-store — Raleigh, North Carolina, United States (website)
- Audio Affair — online and in-store — Deritend, England, United Kingdom (website)
- Audio Ark — online and in-store — Edmonton, Alberta, United States (website)
- Audio Breakthroughs — in-store — Manhasset, New York, United States (website)
and 168 more verified dealers