NAIM 555-PS Power Supply – Compatible with any Naim Product

Description

The reference power supply

The Naim 555 PS DR is the upgrade Naim recommends for every reference-tier source in its line — a separately-housed power supply that replaces the unit’s internal regulation with a dedicated transformer, seven discrete regulator (DR) voltage outputs, and a low-resonance chassis on isolating feet. The audible result is consistently described in reviews and our own listening as a step-change rather than an incremental improvement.

The Discrete Regulator (DR) story

The 555 PS was updated in 2012 with Naim’s Discrete Regulator topology — the result of a two-year R&D programme to engineer Naim’s lowest-noise voltage regulation. Each of the seven supply rails is regulated independently. The chassis is low-resonance with isolating feet to keep mechanical noise from coupling into the audio path.

Massive transformer

The transformer inside the 555 PS is approximately 40% larger than the one fitted to the XPS — five separate windings, seven regulated supply voltages, including a dedicated output for the clock circuitry of the CD555.

Compatible Naim products

• ND 555 — flagship network player
• NDS — reference network player
• NDX 2 — network player
• NDX — earlier-generation network player
• HDX — hard disk player / server
• DAC — Naim DAC
• CDX2 — CD player
• CD555 — flagship CD player

Connection is via two Burndy interconnects (separate analogue and digital output sockets minimise HF noise modulation of the analogue rails).

Where it fits

The 555 PS DR is the upgrade for households who have already invested in a reference-tier Naim source and want to extract everything it has to offer. Pair an ND 555 with a 555 PS DR and the combination is the closest thing to a digital reference standard in current production. We’re happy to demo the upgrade on a customer’s own source at our Bath listening room.

Specification highlights

• Massive transformer, ~40% larger than the XPS
• Seven independently regulated DR voltage outputs
• Five separate transformer windings
• Dedicated analogue and digital output sockets (Burndy)
• Low-resonance chassis with isolating feet
• Two Burndy interconnects required (typically supplied)
• Designed and built in Salisbury, Wiltshire

Order from Hidden Home Technology

Authorised Naim dealer in Bath. Free UK delivery; bring your existing Naim source for an A/B demo at our listening room — we have a 555 PS DR set up alongside reference McIntosh, Mola Mola and Gryphon kit for cross-comparison.

The wider view: Naim 555 PS DR reviews in brief

The 555 PS DR is Naim’s reference power supply, and Naim calls it the finest in its range. It is a separate box that takes over the job of powering a Naim source. The ND 555 streamer has no power supply of its own and needs one of these to play at all. Several other Naim network players can be upgraded with one.

What Hi-Fi? reviewed the ND 555 with this power supply in September 2019, gave the pair five stars and called it “the best sounding digital streaming source we’ve heard”. Jeff Dorgay of TONEAudio lived with the same pairing for the better part of a year and wrote in August 2021 that once it was set up it had no shortcomings at all. He sees more power supply capacity as Naim’s way of going further, and he thinks the keenest owners will want to budget for a second 555 in time. Back in 2013 TONEAudio tried Naim’s DAC with the 555 PS and wrote “Once you hear it, you will never go back”.

It is worth knowing that none of these reviews tests the power supply by itself. TONEAudio also found the pair harsh and flat when first switched on. It took about a week of playing to come right, so the magazine suggests leaving them on.

So it suits someone who already owns one of those Naim sources and wants more from it without changing the box they know. We also sell the ND 555. Bring your own Naim source to our listening room and hear it with and without the 555 PS DR.

What the reviewers say, in a nutshell

• What Hi-Fi?, September 2019. Five stars for the ND 555 with this power supply and the best streaming source it had heard.
• TONEAudio, Jeff Dorgay, August 2021. The ND 555 with its power supply is brilliant once set up and run in. A second power supply is the next step for the keenest.
• TONEAudio, Earle Blanton and Jeff Dorgay, October 2013. With Naim’s DAC the 555 PS made for a stunning experience.

Read what the critics say about more of our power supplies in The Hi-Fi Review Bible.