Pioneer VSX-S520
A very slim 5.1-channel AV receiver (AVR) built for tight spaces; a low-profile option prioritizing placement flexibility.
Overview
The VSX-S520 is an ultra-slim 5.1-channel AVR (about 2.75-inch tall). It offers 4 HDMI inputs/1 output (ARC), 4K/60p 4:4:4 pass-through with 1080p→4K upscaling, built-in Wi-Fi/Bluetooth/Chromecast/AirPlay, and MCACC auto calibration. High-res playback includes FLAC/WAV/ALAC 192 kHz/24-bit and DSD 2.8/5.6 MHz [1]. Official firmware updates exist, with records including AirPlay 2 support and service stability fixes through 2021 [1][2].
Scientific Validity
\[\Large \text{0.3}\]Manufacturer specs cite 50 W/ch (4Ω, 1 kHz, 1.0% THD, 2 ch) / 80 W/ch (4Ω, 1 kHz, 1.0% THD, 1 ch) [1]. Absent full-band, low-distortion third-party measurements (20 Hz–20 kHz, low THD+N), audible transparency cannot be established. Still, this is a conventional AVR without pseudo-scientific claims. Net: borderline problem level → 0.3.
Technology Level
\[\Large \text{0.4}\]Integrating streaming (Chromecast/AirPlay) and MCACC in a very slim chassis is sensible engineering [1]. However, no HDMI 2.1/8K or eARC, and room EQ is basic by current standards. Competent but not cutting-edge → 0.4.
Cost-Performance
\[\Large \text{0.9}\]Denominator (this unit’s market price): 499.95 USD (ABC Warehouse) [3].
Cheapest equal-or-better alternative: Denon AVR-S570BT (5.2 ch, 70 W @ 8Ω, 20–20 kHz, 0.08% THD, HDMI 2.1/8K/eARC) plus Chromecast with Google TV (4K) to match built-in streaming. Prices: 399 USD [4] + 49.99 USD [5] = 448.99 USD.
Equivalence note: Same 5.x use case; S570BT exceeds video I/O and publishes stricter audio specs; adding Chromecast restores network streaming parity [4][5].
Computation: 448.99 ÷ 499.95 = 0.898 → 0.9.
Reliability & Support
\[\Large \text{0.4}\]The product page still hosts a latest firmware link, and documented updates (including AirPlay 2 and service fixes) run through 2019–2021 [1][2]. Warranty/RMA data aren’t published and long-term parts/service clarity is limited. Middle-of-the-road → 0.4.
Rationality of Design Philosophy
\[\Large \text{0.5}\]The design prioritizes space efficiency via Class-D amplification and standard digital processing. It avoids non-scientific add-ons; trade-offs are explainable by engineering constraints rather than myths. Skipping HDMI 2.1/eARC and advanced room EQ limits future-proofing, so overall average rationality → 0.5.
Advice
If you must have a very slim AVR, 5.1 channels suffice, and you want built-in streaming, the VSX-S520 remains workable. If you plan for 8K/4K120, eARC, or want better headroom and longevity, the Denon AVR-S570BT + Chromecast 4K bundle (total 448.99 USD) is stronger value today [4][5]. Also note the S520’s power figures are at 1 kHz / 1.0% THD; set expectations accordingly [1].
References
- Pioneer Home Audio, “VSX-S520,” https://pioneerhomeusa.com/vsx-s520-2 (accessed 2025-08-20). Key specs: 4Ω, 1 kHz, 1.0% THD—50 W/ch (2 ch) / 80 W/ch (1 ch); HDMI 4 in/1 out; Wi-Fi/Bluetooth/Chromecast/AirPlay; MCACC; page hosts firmware links.
- Pioneer Home Audio, “Firmware Update VSX-S520 (11-24-2021),” https://assets.pioneerhomeusa.com/product-firmware/Firmware_Update_for_VSX-S520_11-24-2021.pdf?v=1684718363 (accessed 2025-08-20). Records include AirPlay 2 support and service fixes.
- ABC Warehouse, “PIONEER VSXS520,” https://www.abcwarehouse.com/pioneer-vsxs520-51-ch-slim-av-receiver (accessed 2025-08-20). Price shown: 499.95 USD.
- Denon, “AVR-S570BT – 5.2ch 70W 8K AV Receiver,” https://www.denon.com/en-us/product/av-receivers/avr-s570bt/300614-new.html (accessed 2025-08-20). Direct price: 399 USD; 70 W (8Ω, 20–20 kHz, 0.08% THD, 2 ch), HDMI 2.1/8K/eARC.
- Google Store, “Google TV Streamer (with comparison to Chromecast with Google TV 4K),” https://store.google.com/product/google_tv_streamer?hl=en-US (accessed 2025-08-20). Chromecast with Google TV (4K) price: 49.99 USD.
(2025.8.20)