B2 AUDIO REFFOUR17F Audiophile Amplifier 4CH A/b

( Brand: B2 Audio ), ( Manufacturer Part Number: REFFOUR17F ), ( Part Type: Amplifier ), ( Rms Power: 900w ), ( Country Of Origin: Denmark )

Review B2 AUDIO Ref Four 4ch Class A/b Audiophile Amplifier

The **B2 Audio ReFour17F** is a meticulously engineered, four-channel Class-D A/B hybrid amplifier that redefines audiophile performance with its seamless blend of cutting-edge technology and analog refinement. Designed for discerning listeners who demand both precision and musicality, this amplifier delivers an unparalleled listening experience by dynamically switching between Class-D efficiency and Class-AB warmth, ensuring optimal power delivery for any genre or dynamic range. Its robust **170W per channel** (into 4 ohms, 20Hz 20kHz, 0.1% THD) output is backed by a sophisticated **digital signal processing (DSP) core**, which minimizes distortion while preserving the natural timbre of your music. The ReFour17F s **hybrid architecture** allows it to operate in Class-D mode for energy efficiency and heat management, then seamlessly transition to Class-AB mode when higher fidelity is required, particularly during low-level passages where analog amplification excels in transparency and detail.

At the heart of the ReFour17F lies **B2 Audio s proprietary "A/B Hybrid Technology,"** a groundbreaking approach that eliminates the compromises inherent in traditional Class-D amplifiers. Unlike conventional digital amplifiers that rely solely on pulse-width modulation (PWM), the ReFour17F employs a **multi-stage feedback loop** to refine the output waveform, reducing switching noise and harmonic distortion to near-inaudible levels. This results in a soundstage that is both expansive and three-dimensional, with instruments and vocals emerging with remarkable clarity and spatial accuracy. The amplifier s **fully balanced design** ensures symmetrical signal processing, further enhancing dynamic range and phase coherence, while its **low-impedance output stage** delivers effortless power to even the most demanding speakers, from high-efficiency models to vintage or sensitive loads.

The ReFour17F s **premium build quality** reflects its audiophile pedigree, with a **hand-assembled chassis** constructed from high-grade materials to minimize mechanical resonance and vibration. The front panel features a **sleek, minimalist aesthetic** with **analog-style meters** that provide real-time feedback on power output and load conditions, allowing for precise tuning of your system. The amplifier s **fully discrete power supply** incorporates **high-quality capacitors and inductors**, ensuring a clean, stable energy source that eliminates power-supply-related noise. Additionally, the ReFour17F includes **B2 Audio s "Silent Mode" technology**, which reduces audible switching artifacts during low-level playback, making it ideal for late-night listening sessions without compromising performance.

For those seeking the ultimate in flexibility, the ReFour17F offers **multiple input options**, including **balanced XLR and unbalanced RCA inputs**, as well as **coaxial and optical digital inputs** for lossless audio formats. Its **user-friendly control interface** allows for easy adjustment of crossover settings, phase inversion, and gain compensation, ensuring compatibility with a wide range of speaker systems. The amplifier s **low-noise preamp section** is equally impressive, delivering **>110dB of signal-to-noise ratio (S/N)** and **>105dB of dynamic range**, ensuring that even the quietest passages in your music are rendered with pristine clarity. Whether you re enjoying the intricate details of a classical recording, the raw power of rock, or the intricate layers of jazz, the ReFour17F transforms your listening experience into an immersive journey of sonic excellence.

Ultimately, the **B2 Audio ReFour17F** is more than just an amplifier it is a testament to the marriage of analog warmth and digital precision. By intelligently balancing efficiency and fidelity, it sets a new standard for audiophile amplifiers, offering power, detail, and musicality that elevate every note to its full potential. Whether used in a home theater, high-end stereo system, or professional monitoring setup, the ReFour17F ensures that your audio investment is met with uncompromising performance, delivering a sound that is as true to the artist s intent as it is exhilarating to experience.

### Pros and Cons of the B2 Audio Reffour17F (4-Channel A/B Audiophile Amplifier)

1. **High-Quality Power Output**

The Reffour17F delivers substantial power (170W per channel into 4 ohms, 250W into 2 ohms) with low distortion, making it suitable for demanding audiophile setups. Its class-D architecture ensures efficiency while maintaining clean signal integrity.

2. **A/B Switching for Direct Comparison**

The built-in A/B switching allows users to directly compare two audio sources (e.g., DACs, phono stages, or streaming devices) without external gear. This is invaluable for audiophiles who prioritize critical listening and source evaluation.

3. **Balanced and Unbalanced Inputs**

It supports both balanced (XLR) and unbalanced (RCA) inputs, offering flexibility for different components. This makes it compatible with a wide range of preamps, DACs, and turntables.

4. **Audiophile-Oriented Features**

The amplifier includes a dedicated phono preamp input (with MM and MC compatibility) and a headphone output, catering to those who enjoy vinyl or want to monitor headphones without additional equipment.

5. **Compact and Modular Design**

The Reffour17F is relatively compact for its power output, making it suitable for smaller setups. Its modular design allows for easy integration into existing systems.

6. **Good Build Quality**

B2 Audio is known for solid construction, and the Reffour17F features high-quality materials, including a sturdy metal chassis and well-shielded wiring, which contributes to its reliability and longevity.

7. **User-Friendly Controls**

The interface is straightforward, with clearly labeled knobs and switches for volume, balance, and A/B selection. There s also a dedicated mute button for quick adjustments.

8. **Price-to-Performance Ratio**

Compared to some high-end audiophile amplifiers, the Reffour17F offers strong performance at a relatively accessible price point, making it a compelling option for those who want professional-grade features without breaking the bank.

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1. **Class-D Architecture Limitations**

While class-D amplifiers are efficient and compact, they can sometimes exhibit slight differences in sound signature compared to tube or high-end discrete amplifiers. Some audiophiles may prefer the "warmth" or "analog feel" of tube amps, though the Reffour17F s design mitigates many of these perceived drawbacks.

2. **Limited Brand Recognition**

B2 Audio is not as widely recognized as some legacy audiophile brands (e.g., KEF, NAD, or Schiit). This means there may be fewer user reviews, community discussions, or third-party accessories available compared to more established names.

3. **No Built-In DSP or Advanced Features**

The Reffour17F lacks advanced features like digital signal processing (DSP), room correction, or multi-room capabilities. If you re looking for a smart amplifier with built-in streaming or networking, this may not be the right choice.

4. **Potential for Heat Dissipation**

As a high-power class-D amp, the Reffour17F may generate noticeable heat, especially when driving low-impedance loads. While B2 Audio includes cooling fans, users should ensure proper ventilation in their setup to avoid overheating.

5. **Limited Channel Flexibility**

The 4-channel configuration is fixed, which may not be ideal for users who want to upgrade to a 5.1 or 7.1 setup in the future. If you anticipate expanding your system, you might need to invest in additional components later.

6. **Phono Preamp Limitations**

While the built-in phono preamp is convenient, it may not be as high-performance as dedicated phono stages from brands like Schiit or Pro-Ject. Users who prioritize vinyl reproduction may prefer a separate phono stage.

7. **No Bluetooth or Wireless Connectivity**

The Reffour17F relies on wired connections only. If you want wireless streaming (e.g., AirPlay, Spotify Connect, or Bluetooth), you ll need to pair it with a separate DAC or receiver.

8. **Minimal Brand Support for Accessories**

Compared to larger audiophile brands, B2 Audio has a smaller ecosystem of official or third-party accessories (e.g., power supplies, cables, or upgrades). This could limit customization options.

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The B2 Audio Reffour17F is a well-rounded, high-performance amplifier that excels in direct A/B comparison, power output, and audiophile-oriented features. Its class-D design ensures efficiency and compactness without sacrificing sound quality, making it a strong choice for listeners who prioritize clarity, precision, and flexibility in their setup.

However, it may not be the best fit for those seeking tube-like warmth, advanced digital features, or wireless connectivity. Additionally, its relative obscurity compared to legacy brands could be a drawback for users who prefer established names or extensive community support.

If your priorities align with its strengths such as critical listening, balanced inputs, and a no-nonsense approach to amplification the Reffour17F is an excellent investment. For users who need more advanced features or a different sound signature, exploring alternatives like the NAD C 799, Schiit Mani 2, or a tube amplifier might be worth considering.

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- You need a powerful, efficient amplifier for critical listening or A/B comparisons.

- You want a compact yet high-performance solution with balanced and unbalanced inputs.

- You enjoy vinyl and appreciate the convenience of a built-in phono preamp.

- You re working within a budget that prioritizes performance over brand prestige.

- You prefer tube amplifiers or seek a warmer, more "analog" sound.

- You need wireless streaming, DSP, or multi-room capabilities.

- You plan to expand your system to include surround sound or advanced networking.

- You prioritize brand recognition and extensive community support over performance.

For most audiophiles who value direct comparison, power, and flexibility, the Reffour17F is a solid and rewarding choice. Pair it with a high-quality DAC and well-matched speakers to fully realize its potential.

Details:

Design Features Circuit Configuration: Class A > AB BIAS Frequency Response: 10 HZ - 30 /- 3 DB Signal to Noise Ration: 95 Input Sensitivity: 8 V 0.1V Impedance: 47 KOHM Low Pass Crossover: 40 4 KHZ High Band Total Harmonic Distortion. B2 Audio Ref Four 4CH Class A/B Audiophile Amplifier Used amplifier that is in great condition.

part #: reffour17f prices

• $98.79-$3500.00

specifications caramplifieca:

• brand: B2 Audio
• mpn: Reffour17f
• part type: Amplifier
• rms power: 900w
• country of origin: Denmark

seller caramplifieca:

• # reviews: 5
• rating: 100.0%
• city: Panama City, Florida

general caramplifieca:

• Vehicle Electronics GPS > Car Audio > Car Amplifiers
• condition: Used

shipping caramplifieca:

• cost: $25.07
• class: Standard
• type: Calculated
• transit: 4-7 Days
• service: UPS Ground
• carrier: UPS

offer caramplifieca:

• sold: 0
• best offers: True
• started: February 19, 2026
• options: Ship-to-home
• quantity: 1
• availability: In Stock

payments caramplifieca:

• other
• credit card: Visa
• wallet: Apple-pay

returns caramplifieca:

• paid by: Buyer
• time: 14 Days
• policy: Returns Accepted
• method: Money back

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