Rotel A14 Integrated Amplifier/DAC and CD14 CD Player

The Tradition Continues

Equipment report
Categories:
Integrated amplifiers,
Disc players,
Digital-to-analog converters
|
Products:
Rotel A14,
Rotel CD14
Rotel A14 Integrated Amplifier/DAC and CD14 CD Player

To check out the A14’s phono input, I connected my turntable to the A14—not directly, though. Since I have a moving-coil cartridge, I used a Rothwell Headspace headamp to boost the cartridge output to a level that the A14’s moving-magnet phonostage could handle. (If you’re not familiar with a headamp, think of it as an amplifier that performs the same duties as a step-up transformer, boosting the signal level of an mc cartridge to that of a mm cartridge, but not applying RIAA playback equalization.)

Some of the files I use for component evaluation are high-resolution, so to evaluate the CD14, I converted a few of them to 44.1kHz sampling rate/16-bit WAV files and then burned them to a CD-R. I prefer black CD-R blank CDs, which may reduce scatter of the laser beam. Some CD players won’t read these, but the CD14 read them without a hiccup. I also used these converted files to test the Bluetooth connection. Both the CD14 remote and the A14 remote have numeric pads that let you access a track directly; without this feature you must advance through tracks manually to reach the one you want to hear—a real pain when your CD has lots of tracks.

To check out the headphone input, I plugged my HiFiMan HE-400s into the front panel jack. These planar-magnetic headphones are moderately low in sensitivity, and usually need a fairly hefty amp. I needed an adaptor to fit the ¼" plug into the 3.5-mm jack in the front panel of the A14. When I plugged in the ’phones, the speaker output did not cut off, so I had to turn off the speakers via the front panel. The A14’s internal headphone amp had plenty of power to drive the HiFiMans, and sounded very good doing so. If you’re a serious headphone listener, you’ll want a separate headphone amplifier, but the A14 is good for occasional headphone use.

Balance and tone controls were once commonplace, but lately have almost disappeared from the hi-fi scene. Now they’re making a comeback in integrated amplifiers. On the A14, these controls are accessible either through the menu or from the remote control. The remote control is really the only useful way to access the tone controls. First you have to press the bypass button to engage the tone controls (normally they are bypassed). The bass and treble controls both work as you would expect, with fairly gradual action in their respective regions. The balance control is also accessible through the remote control, and is always engaged. This system works and minimizes the number of controls on the front panel, but for serious use it isn’t as handy as actual knobs on the front panel. However, if you don’t need or want to use these controls, you’d probably rather they didn’t clutter up the faceplate.

Sound
For a variety of reasons I do most of my listening these days to digital music streamed from a central NAS drive over my home network and rendered by a network music player, either a laptop computer running a program like Roon or JRiver Media Center or a dedicated music player like the SOtM sMS-1000SQ, converted to an analog signal by a DAC. Control of my music playback is through the appropriate app installed on my iPad. Although I have a lot of ripped CDs, I also listen to many downloaded high-resolution files. To establish a familiar benchmark for comparison, I started listening to digital music, using the SOtM network music player connected to the A14’s internal DAC via its PC-USB input. (I’m using a limited number of musical selections in this review since we need to evaluate the A14’s many inputs.)

“Folia Rodrigo Martinez” from the album La Folia 1490-1701 was ripped from the CD Alia Vox AFA 9805 as an AIFF file. Played by Jordi Savall and a small band of Renaissance music specialists, it’s a lively, energetic piece. Most Renaissance music doesn’t have much bass, but this piece has a drum that extends into the mid-20Hz range. Of course, the tiny KEF speakers can’t begin to play that low, but driven by the A14 they actually surprised me with how much upper-bass impact they had. They also captured percussionist Pedro Estevan’s very light brushes of his sticks on the drum—something that often disappears beneath the noise floor. Throughout the piece, the many percussion effects were plainly audible, more so than with many more expensive components. What was not done as well was the reproduction of Savall’s viola da gamba—a cello-like instrument from the Renaissance and Baroque eras. The viola da gamba plays the main tune, but unfortunately it was slightly muffled, without the harmonic richness that’s a part of this recording.

The Tallis Scholars’ “Miserere” from their album Allegri’s Miserere & Palestrina’s Missa Papae Marcelli is a 96/24 FLAC file. “Misere” is an a capella work, with a small choral group in the front, a solo tenor narrator, and a small solo group at some distance behind the main group. The A14 projected the piece with a huge soundstage; when the solo group behind the main group entered, the rear of the soundstage was illuminated more brightly than I’ve heard it before. The solo tenor was portrayed without any brittleness, a trait I sometimes hear from lesser components. His vocal shadings were quite expressive, including the barely detectable vibrato he uses at times. The echo of the solo group was realistically integrated into the overall soundstage about as well as I’ve heard it. The A14 widely spread the soundstage between the speakers, with the solo tenor firmly positioned in the center.

Shelby Lynne’s album Just a Little Lovin’ is a DSD64/DSF recording sourced from Acoustic Sounds. The title song was reproduced with excellent detail across the frequency spectrum. The A14 captured delicate inflections of Lynne’s voice, so that I could easily understand her phrasing as she strove to project meaning and emotion. Although the KEF speakers don’t go too deeply into the bass, the A14 made the LS50s sound like much larger speakers, projecting lots of punch and impact that almost made me forget there’s a lot of deeper bass in this song. The A14 was particularly good at reproducing percussion; at one point, the percussionist taps a cymbal very lightly, and the A14 reproduced the barely audible cymbal ever so convincingly. It was all there—the initial transient as the cymbal was struck, the sustain, and the decay as it gradually faded into inaudibility. This track, recorded at a low level, needed a volume setting of 81 to achieve normal playback level, leaving plenty of headroom. OK, so that’s our benchmark for these pieces, let’s see how they sound through other inputs.

A configuration I imagine will be popular with many readers would be the combination of the CD14 driving the A14. So I popped the test CD-R into the CD14 and started listening, first with the CD14’s internal DAC. This is what you’d hear if you buy the CD14 to use with an amplifier that lacks an internal DAC.

 “Just a Little Lovin’” lacked all the bass impact and slam I’ve heard from the high-resolution file. Lynne’s vocals were mostly smooth and breathy, but, a couple of times, had a very slightly edgy sound.

On “Miserere” I heard more of this edginess when the main choral group sang. I had expected to hear it, if at all, when the solo tenor entered, but his part was clean as a whistle. The solo group was imaged at a greater distance behind the main group and the reverberant echo that occurs when they sing was more smeared. The soundstage was not as well defined as it was with the high-resolution file.

On “Folia Rodrigo Martinez” I again heard a slight edginess, and the bass had less impact than the original file.

Next, I switched to the DAC in the A14, connected to the SPDIF coaxial output from the CD14. In this configuration, I used the CD14 as a transport, connected via the digital output to the A14. I played the same CD.

On “Folia Rodrigo Martinez” the first thing I noticed was an increase in bass impact over the CD14 with its internal DAC. Then I noticed there was less edginess. Finally, I noticed that the piece sounded more open and spacious than the CD14 with its internal DAC.

Switching to “Miserere” the story was similar: less edginess for the main choral group, noticeably less smear in the reverberant echo when the distant solo group sang, and an overall more open soundstage, though not as well defined as on the high-resolution file.

On “Just a Little Lovin’” the bass descended deeper, though not as deeply as heard with the high-resolution file playback. There was a smidgen of the edginess left, but less than with the CD14 by itself. Percussion instruments were still realistically reproduced. I think these results tell us the DAC in the A14 sounds better than the one in the CD14.

Finally, I listened to files played from my laptop computer through the Bluetooth connection. I used the JRiver playback software, and instead of installing a driver for the DAC I installed a Bluetooth driver. The A14 then paired with that setup easily. Since Bluetooth wouldn’t support high-resolution files, I converted the files to CD-quality WAV files using the dBpoweramp music-converter program.

On “Folia Rodrigo Martinez” I was surprised at the high quality of the sound. Previous experiences with Bluetooth playback using other components have left me unimpressed. But I heard very respectable sound quality from the Bluetooth connection, so much so that I wondered if part of my previous unfavorable impressions had stemmed from using an iPhone to play music. Could the use of the high-end JRiver software have made that much of an improvement? I heard powerful, impactful bass, as deep as any other source. Instrumental harmonics were accurately portrayed, and dynamics were accurately tracked. A very good experience.

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