Overview

The Crown D-45 is a discontinued 2-channel power amplifier rated at 35 W per channel into 4 Ω, aimed at studio/broadcast and utility duties. It uses Crown’s AB+B topology with IOC (Input/Output Comparator) monitoring and convection cooling, and was sold with a three-year no-fault warranty when new [1][2].

Scientific Validity

\[\Large \text{0.6}\]

Manufacturer specifications state frequency response of ±0.1 dB (20 Hz–20 kHz at 1 W), S/N 106 dB (full-bandwidth FTC power), crosstalk >100 dB (100 Hz–1 kHz), and IMD <0.01% from 0.25 W to rated power. THD is <0.001% from 20–400 Hz, rising linearly to 0.05% at 20 kHz, with IOC indicating distortion >0.05% [1][2]. These figures meet or approach transparent thresholds for FR, S/N, crosstalk, and IMD; THD is higher than today’s best but remains below clearly problematic levels. Net result: generally transparent in normal use, though not state-of-the-art.

Technology Level

\[\Large \text{0.2}\]

The design is conventional analog Class AB+B with controlled 6 V/ms slew rate, high damping factor, and IOC monitoring—solid engineering from the 1980s–1990s but lacking modern advancements like efficient Class D stages, global feedback innovations, or built-in DSP/networking [1][2]. No notable contemporary technical innovation is present.

Cost-Performance

\[\Large \text{0.8}\]

Price basis (used, current market): recent Reverb transactions put the D-45 around 115 USD for a working unit [3].
Cheapest equivalent-or-better comparator: Fosi Audio V3 (with 32 V PSU) at 89.99 USD on the official store; it delivers higher output capability and better measured noise/distortion (manufacturer; third-party review reports ~88 dB SINAD) while providing the same core function of a 2-ch power amp [4][5].
Calculation: 89.99 USD ÷ 115 USD = 0.7825… → 0.8 (first-decimal rounding).
Equivalence note: V3 is a finished 2-ch power amplifier; FR is flat, THD+N and SNR are equal-or-better, and available power comfortably exceeds D-45 at typical loads [4][5].

Reliability & Support

\[\Large \text{0.6}\]

Crown’s D-Series historically shipped with a three-year transferable no-fault warranty and is known for robust construction [1][2]. However, the D-45 is discontinued; today’s buyers are typically purchasing used units with no factory warranty, and long-term parts/service availability is uncertain, which tempers the score.

Rationality of Design Philosophy

\[\Large \text{0.5}\]

The product prioritizes reliability, low noise, and load control (high damping, IOC) over bleeding-edge distortion numbers—rational for utility/studio tasks. In 2025, the same user value (clean amplification at modest power) is achieved more efficiently and cheaply by modern Class D, so the philosophy is serviceable but no longer optimal [1][4][5].

Advice

If you need a compact, quiet, rackable amp for legacy setups, a well-priced D-45 can still be transparent in practice. For new builds, modern Class D options like the Fosi V3 offer lower distortion, far higher output headroom, and lower power consumption at a lower price; they are the pragmatic choice unless you specifically need Crown D-Series form factor or compatibility [4][5]. When buying used, verify channel balance, noise, and thermal behavior, and budget for basic refurbishment if required.

References

[1] Crown Audio, “D-45 (discontinued) — Specifications,” https://www.crownaudio.com/en-US/products/d-45, accessed 2025-08-23.
[2] Crown International (archival datasheet), “D-Series Quick Reference,” https://www.fullcompass.com/common/files/727-DSeriesQuickReference.pdf, accessed 2025-08-23. Test notes: dual mode, both channels driven into 8 Ω for performance; IOC threshold 0.05%.
[3] Reverb, “Crown D-45 2-Channel Power Amplifier — Price Guide / Recent Sales,” https://reverb.com/p/crown-d-45-2-channel-power-amplifier, accessed 2025-08-23.
[4] Fosi Audio (official store), “V3 Mini Stereo Amplifier (options incl. 32V/48V PSU),” https://fosiaudio.com/products/fosi-audio-v3-300w-x2-2-0-channel-hi-fi-stereo-audio-amplifier-with-tpa3255-chip, accessed 2025-08-23.
[5] Audio Science Review, “Fosi Audio V3 Amplifier Review,” https://www.audiosciencereview.com/forum/index.php?threads/fosi-audio-v3-amplifier-review.45757/, accessed 2025-08-23.

(2025.8.23)