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What You Need to Know
What Is This Product and What Does It Do?
The Bryston 3B³ is a stereo power amplifier. Its job is simple: take a low-level audio signal from your preamplifier and make it strong enough to drive a pair of speakers. It’s a power amp only — not an integrated amplifier — so you’ll need a separate preamp or volume-controlled source to complete your system.
The 3B³ is part of Bryston’s Cubed Series — the company’s current top line. Bryston has been building amplifiers since 1973, when founder Chris Russell left a Toronto studio audition with an order for two units. The 3B³ is the latest version of a design that has been refined for over 50 years.
The amp runs in Class A/B. Class A is the most linear, lowest-distortion way to run an amp — but it wastes power and runs hot. Class B is more efficient. Class A/B starts in Class A at lower volume levels and shifts into Class B as power demand goes up. You get low distortion where it matters most, with plenty of headroom for louder music.
The standout engineering feature is the patented Salomie input circuit. Bryston developed it with the late Dr. Ioan Alexandru Salomie. It uses 12 active devices to catch and remove distortion before it can enter the signal path. In most amplifiers, distortion at the input stage gets amplified right along with the music — the Salomie circuit stops that before it happens.
The Salomie circuit works alongside Bryston’s Quad-Complementary output topology. This design improves how transistors match each other and eliminates crossover distortion — a flaw caused by the way transistors hand off signal between them. According to Bryston, the harmonic profile of this output stage mimics a pure Class A design, but at much lower distortion levels.
The 3B³ is a true dual-mono amplifier. Each channel has its own power supply and its own transformer. The only thing both channels share is the power cable. A loud moment on one channel cannot steal power from the other.
Every 3B³ is made in Ontario, Canada. Each unit goes through 100 hours of factory burn-in before it ships. It arrives with a performance certificate showing the measured specs of your specific unit — not a factory average.
Bryston covers the 3B³ with a 20-year warranty on parts and labor. That’s one of the longest manufacturer warranties in consumer electronics.
What Are Reviewers Saying?
Christiaan Punter gave the 3B³ a Highly Recommended designation. He called the Cubed Series “a whole new level” for Bryston. The treble was “supremely subtle and decidedly non-edgy,” he wrote. He said even listeners with a larger budget should give it a serious listen.
Harro Tillema called the 3B³ “enormously robust” yet said it plays with “delicate, almost surgical precision.” His verdict: “The 3B³ belongs in the absolute reference class.”
Tom Martin said the 3B³ “might just combine the best of both worlds: those that love tube amps and those that love solid-state.” He found it a smooth, highly resolved performer across many music genres.
Who Is This Best For?
You have demanding speakers — lower sensitivity designs, 4-ohm loads, or larger floor-standers. The 3B³ delivers 300 watts per channel into 4 ohms, which is exactly what those speakers need.
You’re building a long-term system. The 20-year warranty and Bryston’s track record of repairability make the 3B³ a purchase you can hold onto for decades.
You’re adding a stereo amp to a home theater setup. The 12-volt trigger powers the 3B³ on automatically when your processor does. Balanced XLR inputs give you a clean, hum-free connection to professional-grade gear.
You want verified performance. Every 3B³ ships with a measured spec sheet for your specific unit — not a factory average. Engineers and technically-minded listeners will appreciate that.
You need a shallow-depth amp. At just 11.45 inches deep (without handles), the 3B³ fits in spaces where many comparably powerful amplifiers simply won’t.
How Does It Connect to Your System?
The 3B³ is a power amplifier only — no volume control, no source switching. You’ll need a separate preamplifier, or a DAC or streamer with a volume-controlled output, to feed it. Not sure what you need? Give us a call. It’s exactly the kind of question we help with every day.
On the rear panel you’ll find three input options, all selectable via a toggle switch:
- Balanced XLR — the preferred connection when your preamp supports it. Balanced connections reject interference and hum, especially over longer cable runs.
- TRS (1/4-inch balanced jack) — the same balanced signal as XLR, using a standard 1/4-inch connector. Common in professional and studio gear.
- Single-ended RCA — the standard consumer connection found on virtually every home audio preamp and source component.
Speaker outputs are heavy-duty five-way binding posts. They accept spade lugs, banana plugs, or bare wire.
A 12-volt DC trigger lets the 3B³ power on automatically with a compatible preamp. A rear toggle switches between stereo and bridged mono mode — in bridged mono, both channels combine to drive a single speaker at roughly 400 watts into 8 ohms.
A two-position gain switch (23 dB or 29 dB) lets you match the amp’s sensitivity to your preamp’s output level — a small but useful system-tuning option.
Watch It in Action
The Absolute Sound — Bryston 3B Cubed Power Amplifier Review
Tom Martin of The Absolute Sound walks through the 3B Cubed’s design and shares his impressions in this October 2022 video review.
Pairs Well With
Building your system? Here are some great companions for the 3B³.
- Preamplifiers — The 3B³ needs a preamp. Bryston’s own BP-17³ is a natural match — same Cubed Series engineering, balanced XLR connections, and a 12-volt trigger built in. Any quality preamp with line-level outputs will work equally well. Shop preamplifiers »
- Speakers — The 3B³ puts out 300 watts into a 4-ohm load, making it a great match for demanding floor-standers with complex crossovers or lower sensitivity ratings. Shop speakers »
- Speaker Cables — A quality speaker cable is the last link between amp and speaker. Look for low resistance and the right gauge for your speaker’s impedance and cable run length. Shop speaker cables »
- Interconnect Cables — Use balanced XLR cables from your preamp to the 3B³ whenever you can. Good RCA interconnects work fine if balanced isn’t available. Shop interconnect cables »
- Power Conditioners — Clean AC makes a real difference in a revealing system. A power conditioner also protects the 3B³ from voltage spikes and line noise. Shop power conditioners »
- Sources: DACs, Streamers & CD Players — A DAC or streamer with a volume-controlled analog output can feed the 3B³ directly without a preamp. Look for balanced XLR outputs and at least 1V output voltage. Shop digital audio »
Features & Specifications
Amplifier Performance
Generous, Stable Power — The 3B³ delivers 200 watts per channel into 8 ohms and 300 watts per channel into 4 ohms. In bridged mono mode, a single 3B³ puts out roughly 400 watts into 8 ohms — enough for nearly any speaker in nearly any room.
Very Low Distortion — Total Harmonic Distortion plus Noise (THD+N) is below 0.005% across the full 20Hz–20kHz audio range. That’s a measure of everything the amp adds to the signal that wasn’t in the original recording. Values below 0.01% are generally considered inaudible — the 3B³ is well inside that mark.
Quiet Noise Floor — With a balanced XLR input, the signal-to-noise ratio is better than 111 dB. With single-ended RCA it’s better than 106 dB. The amp is effectively silent between notes — even through efficient speakers in a quiet room.
High Damping Factor — The damping factor exceeds 500 at 20Hz into 8 ohms. The damping factor tells you how well an amp controls a woofer’s motion once the signal stops. A higher number means tighter, better-controlled bass.
Wide Bandwidth — Frequency response runs from below 1 Hz to 100 kHz at the –3 dB point. That goes far beyond what the human ear can detect in either direction. It tells you the amp is not limiting anything in the audible range.
Topology & Design
Patented Salomie Input Circuit — Developed with the late Dr. Ioan Alexandru Salomie, this circuit uses 12 active devices to catch distortion before it reaches the signal path. According to Bryston, it delivers “dramatically less distortion at the input stage” compared to their previous SST2 Series, plus a major improvement in rejecting EMI and RFI noise.
Quad-Complementary Output Topology — This output stage improves how transistors match each other and eliminates crossover distortion. It also reduces output stage capacitance by a factor of four, which helps the amp respond more quickly to fast musical transients. According to Bryston, the harmonic profile mimics a Class A design at far lower overall distortion levels.
True Dual-Mono Construction — Each channel has its own power supply and transformer. The only shared component is the IEC power inlet. A loud burst on one channel cannot steal power from the other.
Fully Convection-Cooled — No fans. Heat moves out through the chassis passively. The amp runs completely silently — and there are no fan motors to fail over years of use.
SoftStart Startup — A microprocessor eases the amp online gradually at power-on. This prevents the sudden current spike that can trip a household breaker.
Switchable Gain — Choose between 23 dB and 29 dB of gain via a rear-panel toggle. This lets you match the amp’s sensitivity to your preamp’s output level.
Connectivity
Three Inputs, All Selectable — Balanced XLR, balanced TRS (1/4-inch), and single-ended RCA inputs are all present. A rear-panel toggle switches between them with no cable swapping required.
Stereo and Bridged Mono — A rear switch converts the 3B³ from stereo to bridged mono. In bridged mode, both channels combine to drive one speaker at higher output. Useful for bi-amplification or for demanding single-speaker setups.
12-Volt DC Trigger — A trigger input and output let the 3B³ power on and off automatically with a compatible preamp or processor.
Build & Finish
Machined Aluminum Enclosure — The chassis and 17-inch black faceplate are machined from aluminum and anodized. The slim, handleless profile suits standard audio racks and home theater cabinetry.
Made in Canada — Every 3B³ is built at Bryston’s facility in Ontario, using many locally sourced components.
100-Hour Factory Burn-In — Every unit cycles between full power and idle for 100 hours before shipping. This stress-tests every component under real thermal conditions.
Individual Performance Certificate — Your 3B³ ships with a spec sheet showing the measured results of your unit specifically — not a generic factory number.
Quick-Reference Specifications
| Amplifier Class | Class A/B |
| Configuration | Dual-mono, two-channel stereo |
| Power Output (per channel) | 200W @ 8Ω | 300W @ 4Ω |
| THD+N (20Hz–20kHz, rated power, 8Ω) | <0.005% |
| IMD | ≤0.005%, typically ≤0.002% |
| Signal-to-Noise Ratio | RCA: <–106 dB | XLR: <–111 dB |
| Damping Factor | >500 @ 20Hz, 8Ω |
| Frequency Response | <1Hz – 100kHz (–3dB) |
| Gain | High: 29 dB (28.28 V/V) | Low: 23 dB (14.14 V/V) |
| Input Sensitivity (High gain) | 1.0V for 100W | 1.4V for 200W |
| Input Sensitivity (Low gain) | 2.0V for 100W | 2.8V for 200W |
| Input Impedance (stereo mode) | Single-ended: ~60kΩ | Balanced +: ~60kΩ | Balanced –: ~12.5kΩ |
| Inputs | Balanced XLR, Balanced TRS (1/4”), Single-ended RCA |
| Outputs | Five-way binding posts (per channel, stereo and bridged) |
| Trigger | 12V DC trigger input and output |
| Power Consumption — Standby | <0.5W |
| Power Consumption — Idle | ≤60W |
| Power Consumption — 2ch at 25W, 8Ω | 440W |
| Power Consumption — 2ch at 200W, 8Ω | 700W |
| Dimensions (H × W × D) | 6.3” × 17” × 11.45” | 160mm × 432mm × 291mm |
| Weight | 42 lbs | 19 kg |
| Finish / Faceplate | Black anodized aluminum, 17-inch (non-rack-mount) |
| Country of Manufacture | Canada (Ontario) |
| Warranty | 20 years, parts and labor (analog electronics) |
Frequently Asked Questions
What else do I need to use the 3B³?
The 3B³ is a power amplifier only. You’ll need a separate preamplifier or a DAC/streamer with a volume-controlled output to send it a signal. Add a pair of speakers and speaker cables and you’re set. Call us at 800-942-0220 and we’ll help you build the right system around it.
Is the 3B³ a good match for my speakers?
With 200 watts into 8 ohms and 300 into 4 ohms, the 3B³ can drive most speakers with authority. But the right match depends on your speakers, your room, and your source levels. Our team handles these questions every day — call us at 800-942-0220 (weekdays, 9am–6pm EST) and we’ll help you dial it in.
What are the differences between Class A, Class A/B, and Class D amplifiers?
Class A runs its output stage at full current all the time. It’s the most linear and lowest-distortion design — but it runs hot and uses a lot of power even at idle.
Class A/B (like the 3B³) runs in Class A at low power and shifts to a more efficient mode as volume rises. It’s a practical balance between performance and heat.
Class D uses high-speed switching to stay cool and efficient. Today’s best Class D designs from quality brands are excellent and have closed a lot of the performance gap with Class A/B.
Can the 3B³ be used in a home theater system?
Yes. It works with any surround processor that has volume-controlled line-level outputs. The 12-volt trigger lets it power on automatically with your system. The XLR and RCA inputs cover every connection type you’ll find on home theater gear.
What is bridged mono mode and when would I use it?
In bridged mono, both channels combine to drive a single speaker at roughly 400 watts into 8 ohms. It’s useful when bi-amping — using two amps to cover different frequency ranges on the same speaker — or when you simply need the most power possible into a demanding driver. Two 3B³ amplifiers running bridged is a popular high-power setup.
How does the 3B³ compare to the Bryston 4B³?
Both use the same Salomie input circuit and Quad-Complementary output topology. The difference is power: the 4B³ delivers 300 watts per channel versus the 3B³’s 200. The 4B³ also has a larger power supply behind it. For most speakers in most rooms, the 3B³ is more than sufficient. If your speakers are power-hungry or you listen in a large room, the 4B³’s extra headroom may be worth the cost. Not sure? Call us — we’ll help you decide.
Does the 3B³ run hot?
Warm, not hot. The amp uses passive convection cooling — no fans — so the chassis handles heat silently. Under normal listening conditions it will be warm to the touch on the top and sides. Give it a few inches of clearance above and on the sides, and don’t stack anything on top of it.
What is Bryston’s 20-year warranty and what does it cover?
Bryston covers all analog audio electronics — including the 3B³ — for 20 years from the original date of manufacture, parts and labor included. The warranty is transferable to a later owner as long as the original bill of sale from an authorized Bryston dealer goes with it. Digital products have a separate 5-year warranty. See bryston.com for the full terms.
What’s in the Box
- Bryston 3B³ Stereo Power Amplifier — Black, 17 Inch Faceplate
- IEC AC power cord
- Individual performance specification certificate (measured specs for your specific unit)
- Owner’s manual
- Warranty card
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