Cyrus 40 PSU Power Supply

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$3,495.00

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The Cyrus 40 PSU is the ultimate external power supply upgrade for the 40 Series, engineered to dramatically enhance sonic performance by delivering clean, precisely regulated power to your system. Designed to interface seamlessly with the 40 AMP, 40 ST, 40 CD, and 40 PPA, this modular component offers an immediate leap in musical realism, clarity, and control.

Housed in the elegant 40 Series aluminum chassis, this advanced external power supply offers a new level of clean, stable, intelligently regulated voltage delivery to any compatible 40 Series host component. At its core is an onboard microprocessor that communicates directly with the connected unit, tailoring the exact power configuration in real time. The result is lower noise, improved timing, and a dramatic leap in sonic performance, no matter which 40 Series product it's paired with.

Key Features

Dedicated High-Current Power: Offloads power demands from your core components to eliminate internal noise and improve resolution
Microprocessor-Controlled: Constant communication with connected devices ensures optimal voltage and current delivery
15-Pin Connectivity: Simple, high-integrity connection to any compatible 40 Series unit
Noise-Free Output: Digitally controlled internal regulation creates a virtually silent power supply
British Design and Build: Hand-assembled in the UK for long-term reliability
5-Year Warranty: Cyrus build quality backed by a long-term manufacturer guarantee
Matching 40 Series Chassis: Anodized aluminum construction with a compact, stackable footprint

40 AMP Enhancements

When connected to the 40 AMP, the 40 PSU provides the power amplifier section with a much stiffer, cleaner power supply, allowing the signal to more faithfully track the source material. The preamp section is completely driven by the PSU as well, resulting in greater dynamic accuracy and less distortion. This division of labor allows the internal supply to focus on the DAC stage, improving resolution even further. The audible result is more weight and authority, greater detail retrieval, improved attack and decay, and tighter overall timing.

40 CD Enhancements

With the 40 CD, the 40 PSU takes over powering the CD motors and master clock. Removing this noisy circuitry from the internal supply reduces interference and jitter. The PSU also handles the analog section of the DAC, while the internal supply focuses solely on the digital domain. This segmentation brings greater imaging precision, improved note articulation, and deeper bass control, with more defined edges and separation.

40 ST Enhancements

When paired with the 40 ST, the 40 PSU powers the analog side of the DAC and the BluOS streaming module, delivering a purer signal path and lowering system noise. This upgrade enhances low-level detail, expands the perceived soundstage, and increases instrument separation. Vocals gain added presence, and the entire performance takes on a more holographic quality.

40 PPA Enhancements

For the 40 PPA phono preamplifier, the 40 PSU delivers further noise reduction to an already ultra-quiet circuit. Phono signals are extremely low-level and sensitive to power supply interference, so the cleaner voltage rails from the PSU yield audible improvements in background silence and micro-detail retrieval. High-gain MC cartridge settings benefit the most, with a noticeably blacker background between notes.

Build Your Cyrus 40 Series System

The 40 PSU enhances any component in the Cyrus 40 Series lineup. Pair it with the Cyrus 40 Amp integrated amplifier for greater dynamic authority, the Cyrus 40 CD for reduced jitter and bass control, the Cyrus 40 ST music streamer for expanded soundstage, or the Cyrus 40 PPA phono preamplifier for the quietest possible vinyl playback. Every 40 Series product shares the same chassis dimensions, display style, and PSU connection, creating a system that performs and looks like it was designed as one. The 40 Series also integrates with the new full-width Cyrus 80 Series, letting you mix compact specialists with full-width power.

The Listening Room Difference

We're a third-generation family business with a brick-and-mortar showroom in Chestertown, Maryland, and a reputation built on trust, not hype. Whether you're visiting in person or ordering online, we bring decades of experience, personalized service, and honest guidance to every interaction. We don't just ship boxes. We help build systems, answer your questions like real humans, and make sure every detail of your setup is right, from the cables to the final connection. Our passion is helping you get the most out of your gear, with support that lasts well beyond the sale.

Downloads

Product Guide User Manual 40 Series Brochure

Specifications

Specification	Details
Low Voltage Supply – Standby	+5V DC
Low Voltage Supply – Operational	+5V DC
Fixed Voltage Supply – Standby	0V
Fixed Voltage Supply – Operational	+24V DC
Variable Supply – Standby	0V
Variable Supply – Regulated	+10V to +45V DC
Variable Supply – Unregulated	+45V or +56V DC
Firmware Updates	Mini USB Port
Dimensions (H x W x D)	88 x 220 x 365 mm (3.46" x 8.66" x 14.37")
Weight	9.4kg (21lbs)

Award: Applause Award (40 Amp + PSU system) "The drama of the occasion is further elevated when the 40 PSU is added, which further bolsters the soundstage and adds greater insight into the mix." "With even better current drive, the music sounds like it has really been set free and punches out an untrammelled bass line into my listening room." "The 40 AMP sounds excellent on its own, but the upgraded power supply makes it better still." The 40 PSU is described as an evolution of the company's PSX-R intelligent power supply, with its own onboard microprocessor to control the output voltages; it's said to provide multiple supplies which are highly stable and almost free of noise.

David Price,StereoNET · October 2024

The 40 PSU boosts the Cyrus 40 Amp's output from 2 x 100W into 6 Ohms to 2 x 113W into 6 Ohms, while also refining the signal path for the DAC and preamp stages. Unlike the PSX-R2 (which focused on stabilizing voltage for front-end circuitry), the newer PSU feeds the power amp stage directly as well, increasing output power and continuing to refine the signal path for the DAC and preamp. When connected, the PSU produced a noticeably dropped noise floor with more air around the instruments and better vocal focus. Bass articulation improved with more grip, and instrumental separation became more apparent. "Not just an upgrade, it's an unlock" that allows the amplifier to "breathe, drive, and articulate to a whole new level." "If you own, or are considering, any part of the 40 Series, the PSU is something you need to hear."

Matt, Audio T Cardiff,Audio T · May 2025

"Adding the 40 PSU is a subtle but worthwhile upgrade and if you can afford it and can accommodate the extra boxes then it is a valid upgrade bringing with it a quieter, slightly more dynamic and more relaxed sound." "Cyrus have always been renowned for their add on power supplies" and appreciates seeing this tradition continue in the 40 series. "It can be added later as funds allow and all the other 40 series components can of course run off their own internal power supplies."

Reference Audio · June 2025

Which Cyrus 40 component benefits the most from adding the PSU?

The 40 Amp typically shows the most dramatic improvement because the PSU offloads the demanding power amp circuits onto cleaner, regulated voltage rails, directly improving dynamics and bass control. Power output increases to 113W per channel. The 40 CD is the second priority, as cleaner power to the disc mechanism and master clock reduces jitter. The 40 ST and 40 PPA also benefit, but the gains are more subtle since their circuits draw less current. If buying one PSU to start, pair it with your 40 Amp.

Does the 40 PSU actually improve sound quality, or is it just marketing?

The improvement is real and measurable. The 40 PSU delivers multiple digitally regulated voltage rails through a microprocessor that communicates directly with the connected component, tailoring power delivery in real time. It offloads demanding power tasks from the host unit's internal supply, reducing electrical noise and improving dynamic headroom. With the 40 Amp, power output increases from 100W to 113W per channel, and owners consistently report better bass definition, a quieter background, and more natural dynamics.

Is one PSU enough, or should I eventually get one for each Cyrus component?

Each 40 PSU powers one component at a time via a single 15-pin cable, so the ideal endgame is one PSU per component. However, the law of diminishing returns applies. The first PSU (on your 40 Amp) makes the biggest difference. The second (on your source, whether 40 CD or 40 ST) adds another meaningful improvement. Beyond that, the gains become increasingly subtle. Most owners find two PSUs across their system to be the sweet spot between performance and investment.

Does needing a separate PSU mean the 40 series is not performing fully without one?

Every 40 series component is engineered to perform excellently with its internal power supply. The 40 Amp, for example, uses an over-specified power supply with independently regulated rails designed to handle dynamic peaks without strain. The 40 CD uses nine separate regulation stages. The 40 PSU is an enhancement, not a fix. It adds dedicated external regulation and a microprocessor that communicates with the host component for real-time power optimization. Think of it as moving from excellent to reference-level, not as completing an incomplete product.

Is the Cyrus 40 PSU configured for US voltage?

Yes. All units sold through The Listening Room are configured for US voltage (120V/60Hz) and include a US power cord. No transformer or adapter is needed.