Cyrus Audio 40 PSU Review: Ultimate Power Upgrade
Refined Power for Reference-Grade Performance
To celebrate 40 years of British hi-fi excellence, Cyrus Audio released the 40 PSU—a reference-class external power supply designed to unlock the full potential of compatible Cyrus components. With upgraded transformer design, superior regulation, and enhanced noise suppression, the 40 PSU offers a significant sonic uplift. In this review, we look at how this premium PSU transforms your hi-fi system, and why it’s the perfect partner for the Cyrus 40 AMP and other units in the lineup.
Design and Build
The Cyrus 40 PSU follows the brand’s iconic half-width chassis design, matching the aesthetics of the 40 AMP and other classic units. It features a solid aluminium casing with a clean front face—no controls, just a subtle power indicator. Every detail is engineered to minimize vibration and EMI, with internal components shielded for noise isolation.
Under the surface, the 40 PSU employs a custom-designed toroidal transformer and fully regulated power rails. Its compact size belies the power and precision it delivers, with clear visual synergy when stacked with other Cyrus components.
Technology and Features
The Cyrus 40 PSU is far more than just a power booster—it is a dedicated, high-precision power plant. Using advanced regulation circuitry and low-noise design, it provides clean, stable DC power to compatible Cyrus devices. It is engineered to isolate sensitive analog and digital circuitry from fluctuations in the main power supply.
It supports dynamic power delivery, meaning it can respond instantly to demand spikes—critical for maintaining transient detail and dynamic range in music playback. Internally, the 40 PSU features upgraded capacitors and components compared to previous PSX-R2 models, contributing to lower distortion and improved timing.
Compatible Devices
The Cyrus 40 PSU is compatible with a wide range of Cyrus products, both current and legacy. These include:
- 40 AMP (with auto-sensing connection)
- i9-XR and Classic AMP
- CDi-XR and CD transport units
- Pre-XR and integrated amplifiers with PSU ports
- DAC-XR and other high-current digital components
Connection is simple—just use the included umbilical cable to attach the PSU to your device. Once connected, the host unit automatically draws regulated power from the PSU.
Specifications
- Type: External regulated power supply
- Output: High-current DC (multi-rail)
- Transformer: Custom toroidal, shielded
- Noise Level: Ultra-low noise regulation
- Compatible With: All Cyrus devices with PSX-R port
- Dimensions: 215 x 75 x 360 mm
- Weight: 6.5 kg
- Finish: Brushed black or silver
Performance Impact
Adding the 40 PSU to a Cyrus amplifier or digital source results in immediate sonic improvements. Backgrounds become quieter, allowing fine details and spatial cues to emerge more clearly. Dynamics are more natural and uncompressed, with improved bass articulation and smoother treble extension.
In amplifiers like the 40 AMP, the PSU offloads power supply duties from the internal circuits, resulting in cleaner signal paths and improved channel separation. When paired with digital components, the PSU helps reduce jitter and improves timing accuracy. The overall effect is a more refined, holographic, and emotionally engaging sound.
Pros and Cons
Pros:
- Significant sonic upgrade to compatible devices
- Ultra-clean regulated power delivery
- Easy to connect and integrate
Cons:
- Only compatible with Cyrus products
- No display or user controls
- High cost for a non-standalone unit
FAQ
Is the 40 PSU compatible with older Cyrus equipment?
Yes. It supports most legacy devices that include a PSX-R port, including earlier integrated amps, preamps, CD players, and DACs.
How is the 40 PSU different from the PSX-R2?
The 40 PSU offers improved internal components, better regulation, and enhanced sonic refinement compared to the PSX-R2.
Does it require configuration or setup?
No. Once connected via the PSU cable, the host component detects and uses it automatically. No configuration is required.
Conclusion
The Cyrus Audio 40 PSU is the ultimate power upgrade for Cyrus systems, offering genuine and measurable sonic improvements. While it doesn't function as a standalone unit, its ability to enhance existing Cyrus components makes it an essential addition for any serious audiophile using the 40 AMP or compatible models. If you’re looking to elevate your system to reference level, the 40 PSU is one of the most impactful upgrades available.