Overview

The Michael Fidler Spartan-20 is a dual-input MM/MC phono preamp designed and built in the UK, combining the Spartan-15 MM section with a discrete class-A MC head amp. It adds useful vinyl-oriented functions (3rd-order 22 Hz subsonic filter, two-step LF crossfeed, mono switch) and parallel RCA line outputs for simultaneous listening/recording. Price as of March–April 2025 is 670 USD direct from the manufacturer. [1][2]

Scientific Validity

Key measured/spec values: RIAA accuracy ±0.1 dB (40 Hz–22 kHz), MM THD <0.0006% (40 Hz–22 kHz, 10 V RMS), MC THD <0.001% at 1 kHz (worst <0.004% at 10 kHz), crosstalk <−72 dB (20 Hz–22 kHz). Signal-to-noise ratio is 78 dB (MM, 5 mV ref., 220 Hz–22 kHz BW) and 77 dB (MC, 500 µV ref., 10 Ω/22 µH, 220 Hz–22 kHz). Independent Audio Science Review measurements confirm excellent linearity and low distortion consistent with the spec. However, the MM/MC SNR figures remain in the ~77–78 dB range, which constrains absolute transparency compared with state-of-the-art electronics. [1][3]

Technology Level

Original in-house design with a discrete, heavy class-A MC stage and carefully executed MM chain, tight RIAA network, proper subsonic filtering, and LF crossfeed. Engineering execution is solid with attention to overload behavior (≈10 V RMS max output) and parallel outputs, but integration is purely analog without novel digital/firmware elements. Overall, competent modern analog implementation rather than breakthrough technology. [1]

Cost-Performance

Conclusion: No cheaper product was identified that matches all of Spartan-20’s user-visible functions (dual dedicated MM/MC inputs, mono, LF crossfeed, 3rd-order subsonic, parallel outputs) and its measured performance (RIAA ±0.1 dB, THD ≤0.001% class with high headroom). Cheaper units such as Schiit Skoll F (399 USD) and iFi ZEN Phono 3 (249 USD) are strong values but do not meet the same combined criteria (e.g., Skoll F THD rises to ≤0.006% and lacks the same feature set; ZEN Phono 3 advertises ±0.15 dB RIAA and higher THD), so they are excluded as equal-or-better comparators. Therefore CP is clamped at 1.0. [1][3][4][5][6]

Reliability & Support

Hand-assembled in the UK with conservative parts choices and an external linear ±17 V supply. The company provides direct worldwide sales and a conditional 2-year warranty, plus repair services; returns are more limited outside the UK. Support footprint is smaller than major brands and failure-rate data is not published, so the score is moderated. [1][2]

Rationality of Design Philosophy

The product aims at measurable fidelity—tight RIAA, low distortion, sensible filtering—without mystique claims, and submits to third-party verification. Costs appear focused on audible parameters rather than cosmetics. That said, the noise performance ceiling keeps it short of fully transparent electronics, so the approach is rational but not disruptive. [1][3]

Advice

If you need a compact dual-input MM/MC stage with excellent linearity, accurate RIAA, and vinyl-friendly utilities (mono, LF crossfeed, proper subsonic), Spartan-20 is a strong engineering choice with verified behavior. If your priority is the lowest possible noise floor versus cost, evaluate whether alternatives’ SNR/THD—and their missing functions—meet your requirements; at present, we do not find a cheaper model that equals Spartan-20 on both features and measurements simultaneously. [1][3][4][6]

References

[1] Michael Fidler (Classic Audio Ltd), “SPARTAN 20 MM & MC Phono Stage” — https://michaelfidler.com/products/spartan/spartan-20-phono-stage/ — accessed 2025-08-27. Key specs inc. RIAA ±0.1 dB, SNR figures, THD, features, power.

[2] Michael Fidler (Classic Audio Ltd), “Order products / Prices & Warranty” — https://michaelfidler.com/order/ — accessed 2025-08-27. Price table (USD 670), conditional 2-year warranty, returns policy.

[3] Audio Science Review, “Michael Fidler Spartan 20 Phono Stage Review” — https://www.audiosciencereview.com/forum/index.php?threads/michael-fidler-spartan-20-phono-stage-review.61993/ — accessed 2025-08-27. Independent measurements and commentary.

[4] Schiit Audio, “Skoll F Balanced Phono Preamp — Specifications” — https://www.schiit.com/products/skoll-f — accessed 2025-08-27. RIAA ±0.15 dB, THD ranges, SNR, features.

[5] Audio Science Review, “Schiit Skoll Balanced Phono Stage Review” — https://www.audiosciencereview.com/forum/index.php?threads/schiit-skoll-balanced-phono-stage-review.48678/ — accessed 2025-08-27. Independent measurements.

[6] iFi Audio, “ZEN Phono 3 — Specifications & RIAA ±0.15 dB / SNR / THD” — https://ifi-audio.com/products/zen-phono-3 — accessed 2025-08-27. Specs and features.

(2025.8.28)