Overview

OPPO Digital (Menlo Park, CA) ceased new product development in April 2018 but announced that support, warranty, and repairs continue via its spun-off team OT Service, Inc. Its HA-1/HA-2 DAC/amps and Sonica DAC earned praise for solid, measurement-first engineering and balanced designs [14][15].

Scientific Validity

\(\Large \text{0.7}\) Third-party measurements and official documents show transparent-class performance for the era. Sonica DAC (ES9038PRO): Archimago reports very low noise/distortion and notes XLR outperforming RCA; device supports PCM 32-bit/768 kHz and DSD512 [1][2]. HA-2 (portable): Secrets’ AP benches show THD+N 0.016% (1 kHz) and IMD 0.008%; similar results at 24/192 [3]. HA-1 (desktop): Official specs list THD+N <0.00056% (A-wtd), SNR >110–115 dB, and FR 20 Hz–20 kHz +0/-0.04–0.07 dB; ASR provides complete measurements [4][5][6]. These meet common transparency thresholds (≈≤0.01% THD+N, ≥~110 dB SNR/DR).

Technology Level

\(\Large \text{0.6}\) Adopted then-flagship ESS converters (ES9038PRO/ES9018), fully balanced analog paths, robust linear PSUs, and on HA-1 a discrete Class-A headphone stage with balanced outputs. Modern and conservative rather than groundbreaking; still technically sound for transparent playback [2][4].

Cost-Performance

\(\Large \text{0.5}\) Company-level CP is averaged across representative categories using last known new MSRP (denominator) vs the cheapest current equivalent-or-better option (numerator).

• Desktop DAC/amp (HA-1: 1,199 USD) → Topping DX5 II (balanced DAC/amp; independent measurements confirm transparency; street 299 USD) ⇒ 299 USD ÷ 1,199 USD = 0.249 [7][8][9].
• Network DAC/streamer (Sonica DAC: 799 USD) → WiiM Ultra (balanced-class outputs via preamp stage, transparent measured performance; 329 USD) ⇒ 329 USD ÷ 799 USD = 0.413 [10][11].
• Portable DAC/amp (HA-2: 299 USD) → FiiO BTR17 (balanced portable, modern codecs/USB DAC; 219 USD) ⇒ 219 USD ÷ 299 USD = 0.732 [12][13].
  Simple average: (0.249 + 0.413 + 0.732)/3 = 0.4645 → 0.5 (rounded to 0.1). Each comparator matches user-visible role/I/O and shows transparent-class performance.

Reliability & Support

\(\Large \text{0.2}\) OPPO announced on April 2, 2018 that it would stop manufacturing, while continuing support, warranty, and repairs with firmware updates “from time to time.” Support pages remain active in 2025 under OT Service, Inc. Discontinuation and sparse updates keep the score low but non-zero [14][15].

Rationality of Design Philosophy

\(\Large \text{0.7}\) Clear, measurement-driven design (balanced topologies, robust PSU, datasheet-consistent performance) and avoidance of occult claims. Sound engineering focus with sensible feature integration [2][4].

Advice

• Already own OPPO gear: Keep using it; leverage the active support channel for repairs/firmware [14][15].
• Shopping today for OPPO-like gear:
  • Desktop DAC/amp — Topping DX5 II, balanced & strong lab results (~299 USD) [7][8][9].
  • Network DAC/streamer — WiiM Ultra, transparent measurements, rich I/O (~329 USD) [10][11].
  • Portable — FiiO BTR17, balanced 4.4 mm/USB DAC/LDAC (~219 USD) [12][13].

References

[1] Archimago’s Musings, “MEASUREMENTS: Oppo Sonica DAC (ESS ES9038PRO),” https://archimago.blogspot.com/2017/06/measurements-oppo-sonica-dac-ess-sabre.html, 2017-06.
[2] Secrets of Home Theater & Hi-Fi, “OPPO Digital Sonica DAC Review,” https://hometheaterhifi.com/reviews/dac/oppo-digital-sonica-dac-review/, 2017-05.
[3] Secrets of Home Theater & Hi-Fi, “OPPO HA-2 DAC and Headphone Amplifier Review,” https://hometheaterhifi.com/reviews/headphone-amplifier/oppo-ha-2-dac-and-headphone-amplifier-review/, 2015-04-22.
[4] OPPO Digital (official), “HA-1 — Features/Specs,” https://www.oppodigital.com/headphone-amplifier-ha-1/, accessed 2025-09-01.
[5] Audio Science Review, “Review and measurements of Oppo HA-1 DAC & Amp,” https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-oppo-ha-1-dac-amp.7191/, 2019-03-31.
[6] OPPO Digital (official), “HA-1 — Images/Support/Price,” https://www.oppodigital.com/headphone-amplifier-ha-1/headphone-amplifier-HA-1-Images.aspx, accessed 2025-09-01.
[7] Apos Audio, “TOPPING DX5 II DAC/Amp — price 299 USD,” https://apos.audio/products/topping-dx5-ii-dac-amp, accessed 2025-09-01.
[8] SHENZHENAUDIO, “TOPPING DX5 II Dual ES9039Q2M,” https://shenzhenaudio.com/products/topping-dx5-ii-dual-es9039q2m-desktop-dac-headphone-amplifier, accessed 2025-09-01.
[9] Audio Science Review, “Topping DX5 II Balanced DAC and Headphone Amp Review,” https://www.audiosciencereview.com/forum/index.php?threads/topping-dx5ii-balanced-dac-and-headphone-amp-review.64264/, 2025-07-20.
[10] Audio Science Review, “WiiM Ultra streamer/preamp review (measurements),” https://www.audiosciencereview.com/forum/index.php?threads/wiim-ultra-streamer-preamp-review.57342/, 2024-09-30.
[11] Crutchfield, “WiiM Ultra,” https://www.crutchfield.com/p_399WMULTRA/WiiM-Ultra-Space-Gray.html, accessed 2025-09-01.
[12] FiiO (official), “BTR17 — product page/specs,” https://www.fiio.com/btr17, accessed 2025-09-01.
[13] FiiO (official), “BTR17 — parameters,” https://www.fiio.com/btr17_parameters, accessed 2025-09-01.
[14] OPPO Digital (official), “Farewell (April 2, 2018) — support continues,” https://www.oppodigital.com/farewell.aspx, 2018-04-02.
[15] OPPO Digital (official), “Product Support,” https://www.oppodigital.com/support.aspx, accessed 2025-09-01.

(2025.9.1)