Headphone Reviews

John Atkinson returned to the Prime in September 2016 (Vol.39 No.9):

I reviewed this elegantly English D/A headphone amplifier in October 2014, with a Follow-Up in November 2015 (footnote 1). I was impressed with what I heard. Yes, at $2000, the Prime is relatively expensive—but, as I wrote, "I liked the palpable way it had with imaging and its clean, clear, but smooth highs."

Another aspect of the Prime that I liked was the fact that, with a firmware upgrade, it could decode and play MQA-encoded files. When this upgrade became available in spring 2016, I downloaded the firmware app, connected the Prime to one of my Mac mini's USB ports, and tried to install the upgrade. Except that the computer didn't recognize the Prime. Scratching my head, I checked all the connections and found that when I'd inserted in the Prime the USB cable's Type A Mini-USB connector, I'd inadvertently pushed the Prime's USB port back inside the case.

Seeing no way inside the Meridian to find out if the damage I'd wrought was reversible, I asked Meridian's PR rep for suggestions. She arranged for me to be sent a new sample, serial no. P2HA-100121. (The original sample's serial number was P1HA-100125.) Holding my breath, I hooked the new Prime up to the Mac mini.

All was well. I could select the Meridian as the default audio output device, and though it doesn't accept DSD data, Apple's AudioMIDI utility indicated that the Prime operated with 24-bit integer PCM data with sample rates ranging from 44.1 to 192kHz. I opened Audirvana Plus, drag'n'dropped an MQA-encoded 24-bit/48kHz FLAC file—"Babylon Sisters," from Steely Dan's Gaucho—onto the playlist window, and pressed Play. The "2x" LED on the Prime's front panel illuminated to indicate that the data were being transformed to 96kHz sampling, as anticipated, and the LED to its right—unmarked on the original sample but now labeled "MQA"—lit up green, to confirm that the file was indeed an MQA file. (Had the file been formally approved by the original record company, it would have glowed blue.)

I was ready to do some serious listening to MQA files. However, as the world of D/A headphone amplifiers has evolved since my 2014 review, before I did so, I compared the Prime with two similarly priced D/A headphone amplifiers: Simaudio's Moon Neo 230HAD ($1499), reviewed elsewhere in this issue by Herb Reichert; and Ayre Acoustics' Codex ($1795), reviewed by Jon Iverson in June 2016. All three amps have USB inputs, though the Moon adds S/PDIF; the Moon and the Meridian, but not the Ayre, have analog inputs; and all three have preamplifier outputs as well as single-ended headphone outputs, though the Ayre also has balanced headphone outputs.

Comparisons
For these listening sessions, I had wanted to use the superb-sounding Audeze LCD-4 headphones that I reviewed last July. However, the LCD-4s' very low sensitivity meant that the Prime just couldn't swing enough volts into them to achieve satisfactory levels—so I used Audeze LCD-Xes and AudioQuest NightHawks, both of which are around 20dB more sensitive than the LCD-4s, and both of which I used in conventional unbalanced mode. I used each D/A headphone amplifier in turn, feeding it data via USB from my Mac mini with Audirvana Plus. (To avoid favoring the first amplifier auditioned with an A/B protocol, comparisons were all A/B/A or B/A/B.)

The Ayre Codex has become the D/A headphone amplifier to beat, I feel, with a full-bodied yet detailed sound. With pianist Simon Trpceski's performance of Brahms's three Intermezzi Op.117 (16/44.1 FLAC, Wigmore Hall Live WHLIVE0081), the Prime had a lighter balance than the Codex, though the image of the piano was similarly palpable. The Prime's tonal balance was more simpatico with the Intrada to Finzi's cantata Dies Natalis, from Introit: The Music of Gerald Finzi, performed by the Aurora Orchestra conducted by Nicholas Collon (24/96 AIFF files, Decca/HDtracks 00028947893578), which sounded a little too dark with the Ayre, particularly with the NightHawk headphones. With Steely Dan's "Babylon Sisters," from Gaucho (DSD64, Acoustic Sounds, not the MQA file referred to above), the comparison was tilted in favor of the Ayre, which handles DSD data in native format; before being fed to the Prime, DSD data needed to be transcoded to 24/176.4 PCM by Audirvana. Even so, other than the drums and bass sounding a tad lightweight compared to the Ayre, and its sound having less impact overall, the Prime did well with this track.

I turned to the Moon Neo 230HAD. Herb had enthused about its sound as a headphone amplifier with analog sources, but was less satisfied with its digital input. When I compared the Moon with the Meridian on the Brahms piano tracks, the image of the instrument was less rounded, the tonal quality a little more dominant in the midrange through the 230HAD. This impression was maintained when I played the DSD "Babylon Sisters," though the Neo 230HAD's ability to natively handle DSD data should have worked to its advantage.

To check my findings, I used the DAC in the Prime and fed its analog outputs to the Moon. The two now sounded much more similar in the mids and highs, and the Neo 230HAD sounded a touch more authoritative than the Prime in the bass with both the Brahms and Steely Dan tracks.

Summing Up
My listening impressions of this second sample of the Prime confirms my positive experience with the original sample.—John Atkinson

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Footnote 1: Meridian Audio Ltd., Latham Road, Huntingdon, Cambridgeshire PE29 6YE, England, UK. Tel: (44) (0)1480-445678. Fax: (44) (0)1480-445686. US distributor: MAI, 351 Thornton Road #108, Lithia Springs, GA 30122. Tel: (404) 344-7111. Web: www.meridian-audio.com.