Overview

The Sonore ultraRendu Plus is a purpose-built network audio streamer that converts Ethernet-connected audio streams to USB output for DACs. Marketed as an audiophile-grade device, it supports various streaming protocols including Roon RAAT, DLNA, and Squeezebox, with support for high-resolution audio formats up to DSD512 and PCM 768kHz. The device measures 4.33” × 4.41” × 1.18” and requires an external linear power supply (6-9V at 1A minimum) sold separately.

Scientific Validity

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Measured performance data (e.g., THD+N, jitter, crosstalk) from credible third-party laboratories could not be identified as of the review date. Per policy, the baseline is 0.5 when measurements are unknown, adjusted down to 0.4 because no independent evidence substantiates audible improvements beyond bit‑perfect digital transport. Manufacturer specifications confirm support up to PCM 768kHz and DSD512 (Native/DoP), external DC 6–9V input, and compact dimensions 1.181” × 4.331” × 4.409” [1][2]. Absent controlled measurements demonstrating lower jitter or noise than transparent thresholds, audible superiority over standard network→USB bridges remains unverified.

Technology Level

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The ultraRendu Plus employs basic computer board technology with minimal differentiation from standard embedded computing solutions. Version 1.3 improvements include relocated clock circuits, redesigned USB implementation, and improved voltage regulation, but these represent incremental modifications rather than significant technical advancement. The multicore processor with DDR3 RAM running Sonicorbiter OS provides standard networking and USB audio functionality available in numerous general-purpose computing platforms. While the specialized audio-focused firmware offers convenience, the underlying technology remains below current industry standards for computer-based audio solutions.

Cost-Performance

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Price (US): 899 USD (Sonore US product page) [1]. We sought finished, single-box streamers offering equal-or-better user functions and performance, specifically Ethernet input, USB Audio Class output, Roon Ready operation, and maximum format support up to at least PCM 768kHz and DSD512. As of this writing, no cheaper finished product was confirmed that meets or exceeds all of these simultaneously with verifiable specifications. Therefore, per the defined formula, CP = MIN(1.0, cheapest equivalent-or-better price ÷ 899 USD) = 1.0, explicitly because no cheaper equivalent-or-better product was identified at the time of review.

Reliability & Support

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Sonore maintains an established presence in the specialized audio market with dedicated support for their network audio products. The company provides standard warranty coverage and has demonstrated continued product development through multiple ultraRendu iterations. Their Sonicorbiter OS receives periodic updates with new features and protocol support. However, as a smaller specialized manufacturer, long-term support sustainability remains less certain compared to major technology companies. The requirement for external power supplies adds potential failure points and complexity compared to self-contained solutions.

Rationality of Design Philosophy

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The design philosophy focuses on claimed audiophile improvements without scientific justification for the substantial price premium. Creating specialized hardware for standard USB bridging functionality demonstrates limited rationality when general-purpose computing solutions provide equivalent measured performance at significantly lower cost. The emphasis on unmeasurable sound quality improvements rather than objective technical specifications reflects an approach contrary to evidence-based audio engineering. While the specialized firmware and Roon Ready certification offer some convenience benefits, these advantages do not justify the extreme price differential over functionally equivalent alternatives.

Advice

For users needing an Ethernet‑to‑USB network transport, the ultraRendu Plus offers compact hardware, broad protocol support (including Roon Ready), and very high format ceilings (PCM 768kHz/DSD512). In absence of independent measurements proving audible gains over other bit‑perfect transports, purchase decisions should weigh verified functionality, ecosystem fit, and total system cost.

References

[1] Sonore (US), ultraRendu Plus product page, https://sonore.us/ultraRendu.html, accessed 2025-08-11 (Price shown: 899 USD; Roon Ready mode; format support list; power 6–9 VDC; dimensions) [2] SONORE JP (Top Wing), ultraRendu Plus page, https://www.sonore-audio.jp/ultraRendu_Plus.html, accessed 2025-08-11 (Format support PCM 44.1–768kHz, DSD64–DSD512; DC6–9V; size 11×3×11.2cm; reference retail price 165,000円)

(2025.8.11)