Meridian Audio Ultra DAC D/A processor

As I mentioned in my review eight years ago of Meridian Audio's 808.2 Signature Reference CD player, I have long been impressed by the British company's components—in fact, ever since the early 1980s, when I purchased a Meridian 101 preamplifier, followed by my very positive experiences with Meridian's MCD Pro and 208 CD players, 518 digital audio processor, D600 and DSP8000 digital active loudspeakers, and, most recently, the Prime and Explorer D/A headphone amplifiers.

All of the Meridian products we have reviewed until now have been the work of a design team led by Meridian cofounder Bob Stuart. However, as Bob is now involved full-time with MQA Ltd. (he remains the chairman of Meridian's board), Meridian's chief technical officer, Richard Hollinshead, now heads up the design team and was responsible for the subject of this review, the Ultra DAC ($23,000).

With its fold-down front panel, the Ultra DAC's large, handsome, black, aluminum case looks identical to that of Meridian's 808i.2 Signature Reference, though it lacks analog inputs and a CD transport. Constructed with a card-frame topology, the Ultra DAC offers every digital input you might wish, all capable of accepting 24-bit data: a USB 2.0 input for connection to a computer, two AES/EBU XLR inputs, two BNC coaxial inputs, two RCA S/PDIF inputs, two optical TosLink inputs, one Meridian Speakerlink input, and an Ethernet port for connection to a Meridian Sooloos System. A dedicated card with a high-current clock as well as FIFO buffering is claimed to minimize phase noise and ensure the lowest possible jitter, all jitter components being folded down below 0.5Hz.


The Ultra DAC has both balanced and single-ended audio outputs and features dual-mono DAC cards, each built on an eight-layer circuit board with low-impedance ground planes and with its own multiple regulated power supply. The output stage incorporates "Hierarchical Converter technology [by MQA]," which Meridian says employs "multiple converters to increase temporal resolution while also reducing noise and quantization errors."

To keep the noise floor low, the power supply is a conventional linear rather than a switching supply; the front-panel display is also electrically "quiet," using a static (non-multiplexed), 20-character, dot-matrix LCD.

The front panel has large, square buttons labeled Source, DSP for selecting among three reconstruction filters (Long, Medium, Short), Display (to change the information shown), and Off; a narrow, rectangular Mute button; and, under the fold-down panel, keys for Volume Up and Down, Setup, and Menu. Pressing Menu lets you adjust the bass, treble, and channel balance, absolute polarity, and a function called LipSync, which adds a delay to synchronize sound with video images; you can also set the Ultra DAC to fixed or variable outputs. All of these buttons are duplicated on the full-function remote control.

I began by using the Ultra DAC without a preamp and with its EQ disabled, its Long reconstruction filter, and its variable output mode, while listening to a variety of recordings at different sample rates and bit depths. My first impressions of the Meridian were of a smooth sound with superb transparency and soundstage depth—even in comparison with my longtime reference, the PS Audio DirectStream DAC, which excels in those areas. The Meridian's low frequencies were powerful and extended, which made the stand-mounted speakers with which I did most of my auditioning sound larger than I expected.

Once you have a large enough music library on your hard drive, it becomes all too easy to forget what's there. I came across Roberta Flack and the late Donny Hathaway singing "I (Who Have Nothing)," which I don't even remember downloading. It reminded me that I hadn't played Hathaway's classic 1971 Live album (24-bit/192kHz ALAC files, Atlantic/HDtracks) in a long while. From his definitive version of Marvin Gaye's "What's Going On," the Ultra DAC suffused me in the club acoustic as I dug the clattery character of Hathaway's Wurlitzer electric piano and Willie Weeks's inspired Fender bass lines. From "The Ghetto"—"Alright, this is it!" shouted a woman behind me in the club before the groove gets going—to the closer, "Voices Inside (Everything Is Everything)," with its multiple solos, I had to get up and dance, soul-clapping as I did so.

I drove myself crazy trying to hear any differences between the Ultra DAC's three upsampling reconstruction filters with this 192kHz-sampled album. Listening to the CD of Live, I felt the Long filter sounded smoothest in the high frequencies, though the CD couldn't rival the 24/192 version when it came to the sense of drive in the lows or the palpability of "Alright, this is it!"

Raphael Wallfisch's unaccompanied cello in John Tavener's Thrinos (ALAC file ripped from CD, Intersound 2847) was presented as a vulnerable but believable image within a warmly supportive acoustic. Again, even with this "Red Book" file, if there were any differences to be heard among the filters, they were very subtle. However, at 3:45 in this haunting work, when Wallfisch (accidentally?) taps his cello, with the Long filter engaged it sounded slightly more like the noise made by a human sliding a mute on to his instrument's bridge.

I was recently sent a CD by a Dutch reader, Wim de Haan, who had written the booklet note. It features the Russian-Dutch pianist Evelina Vorontsova performing piano works by Rachmaninoff: Piano Sonata 2, the Corelli Variations, and the Moments Musicaux Op.16 (STH Quality Classics CD 1416092). It was recorded at 24/192, and the primary microphones were Brüel & Kjër FET/tube 4040s. I didn't know what to expect from this purist recording, but when I played it I was captivated—not only by the sound quality, which was rich and dynamic through the Ultra DAC, but also by Vorontsova's passionate playing.

The Ultra DAC's inclusion of DSD (up to DSD128) decoding for USB data was a surprise, given Meridian's past allegiance to PCM. But if there is a pull for a feature from the customer base, the wise manufacturer serves it up. One of my favorite albums I have as DSD files is Patricia Barber's Café Blue (DSD64, Premonition/Acoustic Sounds). I thought I knew this album well, but as decoded by the Ultra DAC, it sounded more forceful than I was used to—less "DSD-Soft," as it were.

The Ultra MQA Experience
I've already written about my experiences of listening to MQA files decoded by the Meridian Prime D/A headphone amplifier here and here. However, having the Ultra DAC in the house gave me the opportunity to audition this potentially game-changing codec with an ultimate-quality D/A processor.

In this issue's Follow-Up section, Herb Reichert writes about how much he enjoyed streaming MQA files from Tidal, as decoded by Mytek HiFi's Brooklyn D/A processor: "The illusion of space was dramatically improved. Voices felt more solid, more precisely positioned." This was exactly what I experienced with the Ultra DAC decoding MQA files—once I'd figured out how to get Tidal set up correctly.


Tidal identifies MQA files with the "HiFi/Master" label, but at first I couldn't get the Ultra DAC to recognize them as streamed via the Tidal app from my Mac mini, even though I'd selected the Meridian as the Core Audio audio device. My first problem was that I didn't realize that I had to click on the gearwheel icon beside "Meridian USB input" in the Settings menu. When I did, and then selected the necessary "MQA Passthrough" streaming and "Exclusive Mode" options, these settings wouldn't stick. It was only when I realized that I couldn't just exit that screen directly, but first had to return to the setup menu, that I could get the correct settings to apply so that I could get "MQA" to illuminate on the Ultra DAC's display. I can only assume that other Tidal subscribers are smarter than I am!

But once I had it working, oh my! The sound of the orchestra in Grieg's Holberg Suite, from the Trondheim Soloists' In Folk Style (MQA-encoded Tidal HiFi/Master stream decoded at 352.8kHz, 2L 2L-068), sounded magnificent—rich, detailed, and realistic, with excellent soundstage depth—as was the same ensemble's definitive performance of Vaughan Williams's Fantasia on a Theme by Thomas Tallis, from their Reflections (MQA-encoded 352.8kHz Tidal stream, 2L 2L-125). Not all of 2L's MQA-encoded recordings are in that class, however. Herb commented on how much he liked the sound of Mozart's Violin Concerto 4 in D, K.218, performed by soloist Marianne Thorsen with Øyvind Gimse conducting the Trondheimers, from the sampler 2L: The Nordic Sound—2L Audiophile Reference Recordings (MQA-encoded 352.8 Tidal stream). That violin sounded a little too forward for my tastes, though yes, the sense of real performers in a real hall was superb.

Robert Silverman's recent set of 23 of Beethoven's 32 piano sonatas, released as MQA-encoded 24/88.2 FLAC files, sound as if they were recorded in a rather dry hall. The sound of the piano was still both forceful and natural, particularly in Op.111, where Silverman excels, particularly in the double-speed dotted-rhythm section in the second movement. However, as much of a step forward as I feel MQA to be, it can't compensate for the choices made by the recording engineers regarding microphones and where to place them in the hall. When I used the Ultra DAC to compare Silverman's Beethoven MQA files with Vorontsova's Rachmaninoff CD, while both pianists played Steinways, the Red Book-quality recording was superior to the potentially superior-sounding MQA files in conveying her instrument's majesty, and the recording venue's acoustic was more warmly supportive—but there was one significant exception: The MQA recording presented the width and depth of the Steinway in an uncannily realistic manner.

Yes, it's expensive, but Meridian Audio's Ultra DAC joins the expensive dCS Rossini ($23,999) and Vivaldi ($35,999) DACs in offering the best sound I have enjoyed from digital recordings. That its card-frame construction renders it future-proof, and that it offers MQA decoding, are two more layers of frosting on an already very satisfying cake.

Meridian Audio Ltd.
US distributor: MAI
351 Thornton Road #108
Lithia Springs, GA 30122
(404) 344-7111

tonykaz's picture

Geez, I've loved Meridian since the early 1980's. I've Imported Meridian, Retailed Meridian and Owned Meridian. Unfortunately, I had miserable marketplace success with Meridian, phew, why?, I sort-of blamed the "Audiophile-nervosa" syndrome that permeated the USA ( and still does ).

Now, the early part of the 21st Century, Bob Stuart is becoming the very KING of Digital Audio.

I still have my love for Meridian.

Congratulations Mr.Stuart, it was a looooooong time coming but certainly earned.

I wish this lovely device had a price like the Mytek ( which should've been on the Front Cover instead of that ML "to die for" piece )

Tony in Michigan

keithsonic's picture

The review notes an ethernet port for use with Sooloos. It is not clear in the review if this can be used to connect a NAS. Would appreciate if this could be confirmed.

John Atkinson's picture
keithsonic wrote:
The review notes an ethernet port for use with Sooloos. It is not clear in the review if this can be used to connect a NAS. Would appreciate if this could be confirmed.

Although my network recognizes the Meridian - confirmed by using the Fing app on my iPad - the Ultra DAC's Ethernet interface seems to be dedicated to the proprietary Sooloos system. With Twonky Server running on my MacBook Pro and pointing to my NAS, the UPnP apps on the iPad can't find the Meridian to use as the Renderer. They do work with my PS Audio Directream DAC, which is fitted with the network bridge option.

John Atkinson
Editor, Stereophile

keithsonic's picture

Thanks John for checking this out. Trust Meridian though to go down a non-standard route. I remember upgrading my Meridian 500 transport to a universal player and asking Meridian if they planned to support SACD. The answer was something like 'over our dead bodies, it is vastly inferior to PCM'. I bought Ayre and looks like I wont be buying Meridian this time either.

John Atkinson's picture
keithsonic wrote:
Thanks John for checking this out.

And now I am embarrassed to say that after all this time, I tried the UltraDAC with Roon 1.3 and the Ethernet connection and it worked perfectly.

John Atkinson
Editor, Stereophile

keithsonic's picture

Thanks John for belated confirmation. Other reviewers have also noted bespoke Sooloos input so odd that meridian has not corrected. I have pretty much opted for Chord Dave/dCS network bridge combination but will check with my dealer here in London as they do both options. From memory you were undecided between Dave and Ultra. Would the addition of the dCS cha ge your mind. Best Regards

gevorg's picture

~19 bits of resolution is a pretty bad start for a $23K DAC.

hb72's picture

T+A dac 8 manages to reach 20bit as does dCS Rossini (though only nearly), while AQ's DF does ca 17bit. Mind this is some kind of a digital interpretation of combined digital and analog resolution, measured at v. low volume signal. Not sure how representative this is at all when compared to dynamic limitations of the ear. Not not to mention masking etc.

Whats important to the percieved sound quality of a 23k USD dac?

SNI's picture

I wonder when somebody raises his hand, at states, that digital filters do not have intrinsic ringing.
You can put your digital signal through several filters, and no change will be seen.
The so called ringing is just the shape of a bandwith limited signal.
As long as you do not violate Nyquist, there will not be any ringing at all.
The ringting will only be there, when you try to put through frequencies above Nyquist.
In the passband, where the audio signal is situated, the are absolutely no ringing at all.
I think TI´s PCM1792/1794 chips are the ones with the steepest and deepest filters available (stapband attenuation -130 dB), and they state the passband ripple @ ±0.00001 dB.
Which is practically nothing.
So what you do with theese slow roll off non phase linear filters, is actually hunting down ghoests at the cost of introducing phase problems outside the audio band.

Way too many audio enthusiasts believe, that the "ringing" is a part of the audio signal, as a result of the misunderstandings of this measurement in the HIFI press.
You can only use the impulse measurements to see, if the filter is phase linear or not, and to see the depth of the filter.
Regarding phase linearity, then theese minimum phase filters are the first and only attemps I know, that tries to make you like phase errors.
Regarding the depth of the filter, this points solely to the signal delay through the filter, which is of vast interest for "On Stage" purposes, as it is very hard to sing or play properly, if your monitors are delayed.