3.5mm vs 4.4mm: Understanding Balanced Output in Portable HiFi Devices
As portable HiFi devices advance, many music enthusiasts wonder: why does balanced output sound different from standard single-ended output? Devices like the Surfans F28, F35, and X10 now offer both 3.5mm and 4.4mm outputs, but what really changes when you switch between them? This guide explains the technology behind these outputs in a practical, beginner-friendly way.
Table of Contents
What Is a 3.5mm Single-Ended Output?
What Is a 4.4mm Balanced Output?
Differences in Signal Paths
Power, Noise, and Channel Separation
Why Balanced Output Feels “Open”
When to Use 3.5mm or 4.4mm
How Surfans Implements Balanced Output
Conclusion
1. What Is a 3.5mm Single-Ended Output?
The 3.5mm single-ended output is the most common headphone connection. It uses a shared ground wire for both left and right channels.
Advantages:
Universal compatibility
Simple design, lower cost
Efficient for portable devices
Limitations:
Shared ground can cause minor channel interference
Maximum output power is lower
Slightly more sensitive to electrical noise
For everyday listening, lightweight headphones, or portable use, the 3.5mm output remains an excellent choice. Devices like the Surfans F20 demonstrate that even single-ended output can deliver enjoyable sound quality for casual or commuter listening.
2. What Is a 4.4mm Balanced Output?

A 4.4mm balanced output separates positive and negative signal paths for each channel. This design allows:
Higher output voltage
Electronic noise cancellation through differential signaling
Better left-right channel separation
Originally reserved for studio gear, balanced outputs are now standard in advanced portable HiFi devices, such as the F28, F35, and X10.
3. Differences in Signal Paths
To simplify:
3.5mm single-ended: one signal wire + one shared return
4.4mm balanced: two mirrored signal wires per channel
Any noise picked up along the cable is canceled out when the signals recombine at the headphone, resulting in cleaner and more consistent audio.
4. Power, Noise, and Channel Separation
Balanced outputs improve three critical areas:
Output Power
Higher power provides more control over headphone drivers, especially for demanding or full-size headphones. For instance, the Surfans X10 can deliver over 500mW through its balanced output, ensuring distortion-free playback.
Noise Floor
Balanced circuits cancel electrical noise, resulting in:
Lower background hiss
Clearer micro-details
Cleaner listening for sensitive in-ear monitors (IEMs)
Channel Separation
With no shared ground, left and right channels are fully isolated, giving a wider soundstage and precise instrument placement.
5. Why Balanced Output Feels More “Open”
Many listeners report that balanced output sounds:
More spacious
Better layered
More dynamic
This is due to increased headroom, reduced inter-channel interference, and improved transient response, rather than merely higher volume.
6. When to Use 3.5mm or 4.4mm
3.5mm single-ended is ideal for:
Efficient IEMs or portable headphones
Maximizing battery life
Sharing headphones across multiple devices
4.4mm balanced shines when:
Driving high-impedance or full-size headphones
Listening at higher volumes
Enjoying high-resolution audio
Most users benefit from having both options and switching depending on the situation.
7. How Surfans Implements Balanced Output
Surfans integrates balanced outputs thoughtfully across its lineup:
Surfans F20: 3.5mm single-ended output, perfect for everyday use and casual audiophiles.
Surfans F28: Dual DAC architecture with both 3.5mm and 4.4mm outputs, optimized for clarity and balanced tonality.
Surfans F35 (Flagship): Dual ESS9038Q2M DACs with FPGA-assisted signal processing, offering professional-grade 4.4mm balanced output for immersive sound.
Surfans X10 Headphone Amplifier: ES9028Q2M + ES9603Q amplifier, 522mW balanced output, adjustable gain, and high/low filter options.
Each product is designed to suit different user needs—from casual listening with the F20 to advanced audiophile setups with the F35 and X10.
8. Conclusion
Balanced output isn’t just a marketing term—it enhances electrical efficiency, reduces noise, and improves channel separation. While 3.5mm remains versatile and practical, 4.4mm balanced output unlocks the full potential of high-quality headphones.
Understanding the differences between 3.5mm and 4.4mm helps you choose the right connection for your music style, device, and headphone type. With Surfans’ range of HiFi players and amplifiers, there’s a model for everyone, whether you’re an entry-level listener or a professional audiophile.