Introduction 4 ESS ES9039PRO Chips
Digital-to-analog converters (DACs) are critical components in high-fidelity audio systems that convert digital audio signals into analog waveforms with minimal distortion. The ESS Technology ES9039PRO is one of the most advanced DAC chips available, offering exceptional performance with a THD+N (Total Harmonic Distortion + Noise) of -140dB and support for 32-bit/768kHz PCM and DSD1024 playback.
Using 4 ES9039PRO chips in parallel can further enhance performance by reducing noise, improving channel separation, and increasing dynamic range. This article explores the design considerations, benefits, and challenges of building a high-end DAC using 4 ESS ES9039PRO chips.
Why Use 4 ES9039PRO Chips?
1. Improved Signal-to-Noise Ratio (SNR)
- Each ES9039PRO chip has an SNR of 140dB.
- When four chips operate in parallel, noise is averaged, improving the overall SNR.
2. Lower Distortion
- Parallel DACs reduce harmonic distortion by distributing the load.
- ESS’s HyperStream IV modulation benefits from multi-DAC configurations.
3. Enhanced Current Output
- The ES9039PRO has a current output architecture.
- Combining four DACs increases current drive capability, improving analog stage performance.
4. Better Channel Separation
- Dedicated DACs per channel (e.g., two chips per stereo channel) minimize crosstalk.
Design Considerations for a Quad ES9039PRO DAC
1. Digital Input & Signal Distribution
- Input Interface: Supports USB (XMOS or Amanero), I2S, S/PDIF, and AES/EBU.
- Clock Synchronization: A low-jitter master clock (e.g., Crystek CCHD-957) ensures minimal phase noise.
- FPGA or DSP for Channel Management: Needed to split the digital signal across four DACs.
2. DAC Configuration
- Mono vs. Stereo Mode:
- Mono Mode: Each DAC handles one channel (left or right), maximizing performance.
- Stereo Mode: Two DACs per channel for even better dynamic range.
- I/V Conversion:
- Each ES9039PRO outputs current, requiring high-quality I/V converters (discrete op-amps or transformers).
- Example: Discrete JFET-based I/V stage or Lundahl LL1545A transformers.
3. Power Supply Design
- Ultra-Low Noise Linear Regulators: Essential for minimizing power supply noise.
- Example: LT3045 ultra-low-noise LDOs for analog sections.
- Separate Power Rails: Digital, analog, and clock sections should have independent supplies.
4. Analog Output Stage
- Balanced vs. Single-Ended:
- Balanced (Differential): Better noise rejection; requires differential amplifiers.
- Single-Ended: Simpler but may introduce more noise.
- Output Buffer: A high-performance op-amp (e.g., Sparkos Labs SS2590) or discrete Class-A amplifier.
5. PCB Layout & Shielding
- Ground Plane Separation: Digital and analog grounds must be carefully isolated.
- Shielding: RF shielding for sensitive analog sections.
- Short Signal Paths: Minimizes interference and signal degradation.
Performance Benefits
| Specification | Single ES9039PRO | Quad ES9039PRO (Parallel) |
|---|---|---|
| THD+N | -140dB | Improved (lower) |
| SNR | 140dB | 145dB+ (estimated) |
| Dynamic Range | 140dB | 145dB+ |
| Output Current | Moderate | 4x Higher |
| Channel Separation | Excellent | Near-Perfect |
Challenges & Solutions
1. Increased Complexity
- Solution: Use an FPGA (e.g., Xilinx) to manage signal distribution.
2. Heat Dissipation
- Solution: Proper heatsinking and thermal management.
3. Cost
Solution: Optimize design for high-end audiophiles or professional markets.
- Solution: Optimize design for high-end audiophiles
Example Implementation: A Reference Design
- Digital Input: XMOS XU316 USB interface.
- Clock: Crystek CCHD-957 (femto-second jitter).
- DAC Array: 4 ES9039PRO in mono mode (2 per channel).
- I/V Stage: Discrete JFET-based design.
- Output: Fully balanced with Lundahl transformers.
- Power Supply: Multiple LT3045 regulators with separate transformers.
Conclusion
A DAC utilizing 4 ESS ES9039PRO chips represents the pinnacle of digital audio conversion, offering unmatched performance in SNR, distortion, and dynamic range. While the design is complex and costly, the resulting audio quality justifies the effort for high-end audiophile systems, mastering studios, and ultra-high-resolution playback setups.
By carefully managing power supply noise, signal distribution, and analog output stages, a 4-ES9039PRO DAC can achieve performance levels beyond what a single-chip solution can offer.
Would you like a specific schematic or part list for such a design? Let me know how I can refine this further!
