Digital Processor Reviews

I initially used the e1X DAC for several days of casual listening, to make sure all was working correctly. I then started the critical listening, primarily using recordings that I had made myself. Low frequencies were well-defined with good weight, high frequencies were neither exaggerated nor rolled off, and the midrange sounded natural. It was difficult to ascribe an identifiable tonal character to the Bel Canto. As I kept listening, the thing that struck me was how clear a view into recorded soundstages I was experiencing. Whether it was the subtle acoustic of Robert Silverman's 1992 piano recital (16/44.1 rip from CD, Stereophile STPH005-2) or the more reverberant space of In Paradisum from the Portland State Chamber Choir's 2020 album Translations (24/96 WAV, Naxos 8.574124), the ambience surrounding the musicians and singers was clearly and unambiguously identifiable.

Stereo imaging was precise. The dual-mono image of my Fender Precision bass guitar on our Editor's Choice CD (16/44.1 rip from CD, Stereophile STPH016-2, no longer available) was presented as an extremely narrow object centered between the Audiovector QR 7 loudspeakers. With this loudspeaker's rich and extended low frequencies, I found that setting the Bel Canto's Bass EQ to "–2," a reduction in level of 1.2dB below 100Hz, worked well. Conversely, I found myself wishing I'd had the e1X DAC to apply some bass boost when I auditioned the Q Acoustics Concept 50 loudspeaker for my review in our August issue. As I prepared to audition those speakers, I found I wasn't able to place them close enough to the wall behind them, and as a result, their low frequencies sounded lightweight. I did experiment with Roon's DSP to provide some low-frequency boost, but the Bel Canto provides a fit-and-forget solution.

I described the Bel Canto's high frequencies as not being exaggerated. However, after extended listening, I felt that highly compressed rock recordings, like "Bullet With Butterfly Wings" from Rotten Apples: The Smashing Pumpkins Greatest Hits (16/44.1, 256kbps MP3 download), were thrust forward. The MBL N31 I had been using before the e1X DAC was somewhat more forgiving. With recordings like this, I found that applying a touch of downward tilt with the e1X DAC's Tilt control was beneficial.

I used a variety of file formats with Roon to audition the e1X DAC—for some reason, Roon resampled DSD64 files to 24/176.4 PCM—but not having used a D/A processor that acts as a full MQA decoder for some time, I appreciated how the Bel Canto sounded with MQA-encoded files. I cued up Fairytales: Original Master Edition with the late vocalist Radka Toneff accompanied by Steve Dobrogosz on piano (24/192 MQA file, Odin CD9561). "MQA" replaced "Roon" on the Bel Canto's source display, "192" on the sample rate display, and I sat enthralled through all 10 tracks. "Musical gold," I wrote in my 2018 review of this white-glove–mastered reissue. Comparing this version with the 24/192 needle drop I had made from my 1982 LP, the improvement in palpability and involvement with the music reminded me why I had been so enthusiastic about MQA.

Not long after I installed the e1X DAC in my system, I was preparing the CD master files for Molto Molto, an album of three classical-themed works including a piano concerto and a symphony that Sasha Matson had composed for a traditional jazz big band. The original files were the 24/96 WAVs that Kevin Gray and Joe Harley had used to master the LPs. (The 2-LP set, CD, and hi-rez files were scheduled to be released this fall on the Stereophile label.) When converting a hi-rez file to CD resolution, simply sample-rate–converting the file and truncating the bottom 8 bits significantly compromises sound quality. When I prepare a CD master, therefore, I experiment with noise-shaping and dithering algorithms to preserve as much as possible of the original quality. I ended up with two choices for the Molto Molto CD—auditioning them with the Bel Canto DAC, one clearly sounded closer to the 24/96 files, so that is what I submitted to the CD plant. (Sasha agreed with my choice, thank goodness.)

Listening with the Bel Canto Seek App
I installed Seek on my iPhone 11 and logged into my Qobuz and Tidal accounts. Using the app was straightforward. I went to my DropBox folder and selected my hi-rez recording of the Portland State Chamber Choir singing the Eriks Ešenvalds arrangement of "Amazing Grace." "Eth" appeared on the e1X DAC's source display, "88.2" on the sample rate display, and "wav / 24 bit / 88.2kHz / 4234 kbps" on Seek's Player page. I played more tracks, from the iPhone's storage, from Qobuz and Tidal, and Seek worked well. I would have liked an elapsed time display on its Player page in addition to the volume display, but if you don't have Roon, Seek is an excellent substitute.

A Ghost in the Machine moment: I was in the grocery store, about a quarter-mile from home, when my Apple Watch pinged. I had been playing a file from my iPhone with Seek when I paused playback to go to the store. The Watch told me it had resumed playback and that the iPhone was sending the audio data to the "e1X DAC-131," presumably over the internet connection. Good thing I had left the amplifiers in standby!

Listening with headphones
I switched off the Bel Canto's main outputs and selected Headphone. With my Audeze LCD-X headphones plugged into the Bel Canto's front-panel headphone jack, setting the volume control to "77" gave a comfortable loudness, and I relistened to the tracks I had used for my critical listening with loudspeakers. (The Tilt and BassEQ controls are not operative with this output.)

I don't have much to add to my earlier comments. Transparency to the source combined with low-frequency articulation and weight was the e1X DAC's calling card.

Listening with analog sources
To audition the analog inputs, I fed the line inputs with the single-ended outputs of my Ayre C-5xe^MP CD/SACD player; the phono input, set to 0.5mV sensitivity and 100 ohms impedance, was connected to my Linn Sondek LP12/Lingo/Ekos/Arkiv B LP player. AudioQuest Robin Hood speaker cables connected the Parasound amplifiers to first the Audiovector QR 7 loudspeakers I reviewed in the September issue, then to Mission 770 loudspeakers, which I review in the November 2022 issue.

In my review of the digital input performance, I wrote that low frequencies were well-defined with good weight, high frequencies were neither exaggerated nor rolled off, and the midrange sounded natural. However, the thing that struck me most was how clear a view into recorded soundstages I was experiencing. Listening to a variety of CDs fed from the Ayre player's analog output to one of the Bel Canto's line-level analog inputs, I initially felt I was hearing the same sound character. But when I switched to the e1X's AES3 digital input, fed again from the Ayre player, then back to the analog input, the presentation was slightly darker, as if the analog input had placed a finely woven scrim between me and the recorded soundstages.

I experimented with the digital-domain Tilt control. Setting this to +2, which shelves the high frequencies above 1kHz up by 1.2dB, those below 1kHz down by the same 1.2dB, gave a tonal balance that got closer to that with the AES3 digital input. Soundstage depth still seemed a touch foreshortened, however. With Robert Silverman's 1992 live piano recital CD (Stereophile STPH005-2), the acoustic of the Albuquerque church where I had made the recording sounded slightly less reverberant than it had sounded with the digital connection.

I used the e1X's phono input to audition the test pressings of Sasha Matson's Molto Molto. I produced the sessions and oversaw the mixdowns. Joe Harley and Kevin Gray cut the lacquers. The compositions were spread over four LP sides to encompass the recording's wide dynamic range.

With this recording, imaging and soundstaging were very similar to what I had experienced with the line input. Low frequencies sounded powerful, perhaps a bit too much so; the kickdrum and double bass tended to blend. My usual phono preamplifier, a Channel D Seta L, fed to the Bel Canto's line input, set to the same 100 ohm impedance and with the playback level matched, sounded both lighter and clearer, although still darker-tinged than I expected. The sounds of the kickdrum and double bass were better differentiated than they had been with the e1X.

Adjusting the tonal balance with the Tilt control didn't prove to be the solution with the phono input, as the setting that worked best at taming the low frequencies tilted up the high frequencies too much. However, applying a 1.2dB downward shelf below 100Hz with the Bel Canto's Bass EQ control, which doesn't affect the midrange and treble, brought the low-frequency balance closer to that of the Channel D preamp.

Conclusion
Rereading my auditioning notes, I was struck by how difficult it had been to characterize the sound of the Bel Canto e1X DAC. It might use an almost two-decade–old DAC chip, but with its very high resolution, low noise, and equally low distortion—all confirmed in my measurements—this processor really doesn't have a sound of its own. Coupled with its versatile controls and its analog inputs, the e1X DAC is about as good as digital playback gets for a relatively affordable price.

I was also impressed by both the measured performance and the sound quality of the line and phono analog inputs. And the preamplifier's versatile Tilt and Bass EQ controls proved to be a useful bonus in my auditioning of these inputs.