SMSL SU-2 vs SU-1: A Comprehensive Comparison
SMSL has established itself as a leader in affordable high-performance audio equipment, and their SU series of desktop DACs exemplifies this commitment to excellence. With the release of the SU-2, many audiophiles are wondering how it compares to its predecessor, the SU-1. In this detailed comparison, we'll explore the key differences, improvements, and help you decide which DAC best suits your needs.
Overview: Evolution of the SU Series
Both the SU-1 and SU-2 represent SMSL's dedication to delivering reference-grade digital-to-analog conversion at accessible price points. While they share similar design philosophies and compact desktop form factors, the SU-2 brings several meaningful upgrades that enhance performance and connectivity.
DAC Chip: The Heart of the Matter
SMSL SU-1: Features the ESS ES9038Q2M DAC chip, a highly respected component known for excellent performance and low distortion.
SMSL SU-2: Upgrades to the newer ESS ES9039Q2M DAC chip, representing the latest generation of ESS Sabre technology with improved specifications and performance.
The Difference: The ES9039Q2M in the SU-2 offers enhanced dynamic range, lower THD+N (total harmonic distortion plus noise), and improved jitter rejection compared to the ES9038Q2M. While both chips deliver exceptional performance, the SU-2's newer chip provides measurable improvements that discerning listeners may appreciate, particularly in complex musical passages and high-resolution recordings.
Connectivity: Professional Features
SMSL SU-1: Offers USB, optical (TOSLINK), and coaxial (SPDIF) digital inputs, plus RCA and XLR balanced outputs.
SMSL SU-2: Adds professional AES/EBU input alongside optical and coaxial inputs, maintaining both RCA and XLR balanced outputs.
The Difference: The addition of AES/EBU input on the SU-2 is a significant upgrade for professional users and serious audiophiles. AES/EBU is the industry-standard professional digital audio interface, offering superior noise immunity and longer cable run capability compared to consumer formats. This makes the SU-2 particularly attractive for studio monitoring applications and integration with high-end digital transports.
Note: The SU-2 does not include USB input, focusing instead on S/PDIF-based connections (AES/EBU, optical, coaxial). If you primarily connect via USB from a computer, the SU-1 may be more suitable, or you'll need a USB-to-S/PDIF converter with the SU-2.
Audio Performance Specifications
SMSL SU-1:
- THD+N: < 0.0005% (1kHz, A-weighted)
- Dynamic Range: > 118dB (A-weighted)
- Signal-to-Noise Ratio: > 118dB (A-weighted)
SMSL SU-2:
- THD+N: < 0.0003% (1kHz, A-weighted)
- Dynamic Range: > 120dB (A-weighted)
- Signal-to-Noise Ratio: > 120dB (A-weighted)
The Difference: The SU-2 shows measurable improvements across all key specifications. The lower THD+N means even less distortion, while the increased dynamic range and SNR provide a blacker background and better resolution of quiet details. These improvements may be subtle in casual listening but become more apparent with high-quality recordings and revealing audio systems.
Supported Formats
Both the SU-1 and SU-2 support:
- PCM: 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz
- PCM Word Length: 16-bit, 24-bit
- DSD: DSD64 (2.8224MHz)
The Difference: Format support is identical between both models, ensuring compatibility with all common high-resolution audio formats and streaming services.
Build Quality and Design
Both DACs feature:
- Premium metal chassis construction
- Compact desktop form factor
- Similar dimensions (approximately 150mm width)
- Clean, minimalist aesthetic
- Excellent electromagnetic shielding
The Difference: Build quality is comparable between both models, with SMSL maintaining their high standards for construction and finish. Both units feel solid and well-engineered, suitable for long-term use in demanding environments.
Output Configuration
Both models offer:
- RCA unbalanced outputs (2.0Vrms)
- XLR balanced outputs (4.0Vrms)
- Low output impedance for compatibility with various amplifiers
The Difference: Output configuration is identical, allowing either DAC to integrate seamlessly with both consumer and professional audio equipment.
Sound Quality: Subjective Impressions
SMSL SU-1: Known for its neutral, transparent sound signature with excellent detail retrieval. The ES9038Q2M delivers clean, accurate audio reproduction that audiophiles appreciate for critical listening.
SMSL SU-2: Builds on the SU-1's strengths with even greater transparency and a slightly blacker background. The improved specifications translate to enhanced micro-detail resolution and better separation in complex musical passages. The soundstage may appear slightly more three-dimensional, though differences are subtle.
The Difference: Both DACs prioritize accuracy and neutrality over coloration. The SU-2's improvements are evolutionary rather than revolutionary—you're getting refinement rather than a completely different sound signature. In blind testing with typical consumer audio systems, many listeners might struggle to distinguish between them. However, with high-end amplifiers, speakers, and well-recorded source material, the SU-2's advantages become more apparent.
Use Case Scenarios
Choose the SMSL SU-1 if you:
- Need USB input for direct computer connection
- Want excellent performance at a lower price point
- Have a consumer-focused audio system without AES/EBU sources
- Are building a desktop audio setup with USB DAC requirements
- Value proven performance with the ES9038Q2M chip
Choose the SMSL SU-2 if you:
- Require professional AES/EBU connectivity
- Want the latest ESS Sabre DAC technology (ES9039Q2M)
- Have high-end audio equipment that can reveal subtle performance improvements
- Work in professional audio or studio monitoring applications
- Use optical or coaxial sources (CD transports, streamers, etc.)
- Want the absolute best measured performance in the SU series
Price and Value Proposition
The SU-2 typically commands a premium over the SU-1, reflecting its upgraded DAC chip and additional AES/EBU input. However, both models represent exceptional value in their respective price brackets, offering performance that rivals DACs costing significantly more.
For most users, the SU-1 provides outstanding performance and remains an excellent choice. The SU-2 is best suited for those who specifically need AES/EBU connectivity, want the latest DAC technology, or have revealing systems where the performance improvements will be audible.
Technical Comparison Table
| Feature | SMSL SU-1 | SMSL SU-2 |
|---|---|---|
| DAC Chip | ESS ES9038Q2M | ESS ES9039Q2M |
| Digital Inputs | USB, Optical, Coaxial | AES/EBU, Optical, Coaxial |
| Analog Outputs | RCA, XLR | RCA, XLR |
| THD+N | < 0.0005% | < 0.0003% |
| Dynamic Range | > 118dB | > 120dB |
| SNR | > 118dB | > 120dB |
| PCM Support | Up to 192kHz/24-bit | Up to 192kHz/24-bit |
| DSD Support | DSD64 | DSD64 |
| Dimensions | ~150 x 42 x 133mm | 150 x 42.5 x 133.1mm |
Final Verdict
Both the SMSL SU-1 and SU-2 are exceptional desktop DACs that deliver reference-grade performance. Your choice should be guided by your specific needs:
The SU-1 remains an outstanding choice for users who need USB connectivity and want proven, excellent performance at a competitive price. It's perfect for desktop computer audio setups and general audiophile use.
The SU-2 is the better choice for professional applications, users with AES/EBU sources, and audiophiles who want the absolute latest DAC technology and measurably superior specifications. The performance improvements are real but subtle—most noticeable in high-end systems with revealing components.
Ultimately, you can't go wrong with either model. Both represent SMSL's commitment to delivering exceptional audio performance, build quality, and value. Consider your connectivity requirements, system quality, and budget to make the best choice for your specific situation.
Where to Buy
Ready to upgrade your audio system? Both models are available at The HiFi Cat:
Shop SMSL SU-2 Desktop DAC - The latest model with ES9039Q2M chip and professional AES/EBU connectivity
Shop SMSL SU-1 Desktop DAC - Proven performance with USB connectivity and excellent value
We offer competitive pricing, fast shipping, and expert customer support to help you build your ideal audio system.
Have questions about which DAC is right for your system? Contact our team of audio experts—we're here to help you make the perfect choice!
