Overview

The Fosi Audio ZP3 is a compact balanced preamplifier at 200 USD that targets users who need multiple analog sources and 2.1 integration. It provides RCA1/RCA2/XLR inputs and RCA/XLR/Sub outputs (3-in/3-out), three-stage high-pass filtering for the main outputs, a dedicated sub out, L/R balance and tone bypass, per-input volume memory, 12V trigger in/out, and an IR remote. Internally it uses an NJR NJU72315 digitally controlled analog volume IC with ELNA capacitors and gold-plated RCA jacks [1][2].

Scientific Validity

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Manufacturer specifications list THD+N ≤0.0007% (XLR) / ≤0.0008% (RCA), SNR/Dynamic Range ≥112–115 dB, crosstalk ≤−130 dB, and frequency response 20 Hz–20 kHz (±0.2 dB) with HPF options (20/80/120 Hz) and SUB 20–200 Hz band [2]. These exceed common audibility thresholds (e.g., THD+N ≤0.01%, SNR/DNR ≥105 dB), placing the ZP3 at transparent performance by spec. Independent third-party measurements are not yet available; this evaluation is provisional and based on the published data [1][2].

Technology Level

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The architecture is conventional: a line-level analog preamp with digitally controlled volume (NJU72315) and standard op-amp/buffer stages, plus practical add-ons (3-step HPF, sub out, triggers, tone controls). There is no clear breakthrough topology or novel algorithm. Solid engineering choices and features are evident, but the design sits at an industry-average sophistication level rather than pushing technical boundaries [1][2].

Cost-Performance

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Market price is 200 USD [1]. As of Aug 15, 2025, we could not identify any finished preamplifier offering balanced XLR in/out, three-input switching, dedicated sub out with main-channel HPF, and remote/trigger at or below this price. Functionally comparable options cost more—for example, miniDSP Flex (balanced TRS I/O with bass management/DSP) at 549 USD [3] or Schiit Kara F balanced preamp at 799 USD [4]. Therefore no cheaper equivalent-or-better alternative exists; CP is set to 1.0.

Reliability & Support

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Fosi lists free shipping, a 30-day return window, and a 24-month warranty with email/WhatsApp support [1]. Build appears robust (metal enclosure, quality connectors/components) [1][2]. Long-term field reliability data from independent sources is still limited relative to long-established brands, so we keep the score at a solid average.

Rationality of Design Philosophy

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The feature set directly addresses measurable system needs: transparent line-level performance, clean switching, and basic bass management via selectable HPF plus a sub out. The per-input volume memory and trigger I/O improve real-world usability without resorting to non-scientific claims. The overall approach is practical and measurement-aligned [1][2].

Advice

Choose the ZP3 if you need balanced XLR connectivity, multiple analog inputs, and simple 2.1 integration without moving to a pricier DSP preamp. By spec it is transparent for high-fidelity systems. If you don’t use a sub, set the HPF to the full-range position (20 Hz–20 kHz) to avoid unintended bass roll-off [1][2]. Users seeking advanced room correction or digital inputs should consider DSP-equipped units like miniDSP Flex [3], while those needing only single-ended, single-source control may downsize to passive solutions.

References

[1] Fosi Audio – “ZP3 Preamplifer” product page, price, features, warranty. https://fosiaudio.com/products/zp3-preamplifer (accessed 2025-08-15)

[2] Fosi Audio – “ZP3 Preamp” specifications page (THD+N, SNR/DNR, FR, HPF, per-input volume memory, NJU72315). https://fosiaudio.com/pages/zp3-preamp (accessed 2025-08-15)

[3] miniDSP – “miniDSP Flex” (balanced TRS I/O, price). https://www.minidsp.com/products/minidsp-in-a-box/flex (accessed 2025-08-15)

[4] Schiit Audio – “Kara F” balanced preamp (price/specs). https://www.schiit.com/products/kara-f (accessed 2025-08-15)

(2025.8.15)