Manoly‘s Mumblings: The Audio Research CD2 Digital Transport/CD Player
Bruce Manoly

Priorities, Priorities…

Here are my sonic priorities for stereo components. Yours are likely to be different, but this will establish for you where I’m coming from. To begin with, a component can’t be fatiguing. I don’t care how many other things it does exceptionally well. If you don’t want to listen to it, then it’s not really good for much of anything. Second, a component/system needs to have good tonal balance. It’s amazing how many expensive components and pairings fail in this area. Third, a component/system needs to produce accurate timbres. These first three are closely related, and, in my view, absolutely essential. Fourth, (I’m going to lump a bunch of things together here) extension at the frequency extremes, good dynamics, good imaging, and a deep and wide soundstage are very important, but not absolutely essential to me. Fifth, tightness in the bass and high resolution (yes, you can get excellent imaging without exceptionally high resolution) are things I really like to have, but are less important to me than the previous grouping.

The $3,495.00 ARC CD2 arrived well packaged for shipment, a good thing in these days of high volume, low care shippers. The CD2 has a full function plastic IR remote, with key functions duplicated on the front panel. The CD2 is sturdily built, and it passed the scratched CD test with flying colors. The visual aesthetics are good. The CD2 sports an easy on the eyes green vacuum fluorescent display with optical filter. It also comes with handles — I like the handles. The face plate is a gray color, which I like better than the silver. The manual is your basic manual: nothing wrong, nothing special.

When the ARC CD2 arrived, it had been broken in for a total of 3 days. Warren Gehl of ARC recommended that I break it in for an additional week by leaving it on continuous repeat. After only 3 days of break-in, my wife commented that it sounded "tinny". After 4 days of break-in, the treble was noticeably smoothing out. After 5 days of break-in, the treble was smoothing out more slowly, and the bass was getting a little better defined. After 2 weeks I was very happy with the sound. The bass continued to gradually grow tighter over a more extended time period.

I did my evaluation of the CD2 as a CD Player using the single ended analog outputs, and did not use a balanced system or an outboard DAC. While most CD Players have a digital output, very few have a digital input, and the CD2 is no exception. I would like to see this become a more common feature; it would be nice to have if you wanted to get a digital TV satellite dish.

Both frequency extremes are well extended with good pitch definition in the bass. The tonal balance is excellent with an appropriate amount of bass, neither whimpy nor bloated. The treble has better detail resolution than many digital front ends costing up to five times the price. The CD2 is not aggressive, forward, hard or harsh, but neither is it really laid back. At the same time, it’s very highly resolving. On track 2 of Janis Ian’s Breaking Silence (the gold disk from Chad Kassem’s Analog Productions), there is some brush work on cymbals. People at WCES, upon hearing this on excellent systems with $20,000 digital front ends, would ask, "What’s that noise?" The best guess was that someone had left the lever open on a snare drum, and the snare drum was resonating in the studio. The only system at WCES that I heard successfully resolve this to the point where you could tell it was brushes on cymbals, was in the Audio Note room (their DAC costs $18,000+), but the ARC CD2 is also able to resolve it!

For all of its virtues, the CD2 isn’t a cure-all for bad CDs. Harsh/edgy sounding CDs still sound harsh and edgy. I’m tempted to resort to the approach of having a high resolution digital front end for well produced CDs, and a second low resolution CD Player to smooth out those CDs containing the music which is extremely harsh and digital sounding. Before I do that, though, I plan on trying either the ASE from Z-Man, or Taddeo’s Digital Antidote II, both of which are designed to counteract "digitalness." (Jennifer Crock wrote about these in Positive Feedback Vol. 7, No. 1 and Vol. 7, No. 2.) Certain types of music, even live and unamplified, can tend towards the strident/hard/biting end of the spectrum (i.e. trumpets, or Randy Stonehill flailing wildly away on his Martin guitar with the backs of his fingernails). Well-produced CDs with this type of program material absolutely embarrass many high-end systems, but in the three systems I’ve heard the ARC CD2 perform in, it shined in this area. The appropriate bite remained, but the associated digital ugliness was absent.

The first time I heard the CD2, it was in an all-Cary system (CAD-300SE monoblocks, SLP 94 preamp, Diapason Adamantes II speakers, Power Wedge 112, Power Enhancer I, and Wireworld cable). I was stunned. The sense of the musicians being in the room with you was amazing. The CD2 created a sonic hologram with an effectiveness that I’d heard from vinyl, but never before from digital. How much of this is due to the CD2 itself, and how much is due to the fact that almost none of the megabuck digital front ends I heard at WCES were used in conjunction with mini-monitors, remains an unanswered question. The only part that was lacking was the image height, which is a quality that I’ve still only heard done really well on vinyl, as on the tried and true Jazz at the Pawnshop LP.

At home, most of this realism remains, despite the fact that, in my listening room, my speakers don’t have quite the imaging and soundstaging capabilities that the Diapasons did at Arizona Tube Audio. I suspect that the Cary single ended 300B monoblocks that were driving the Diapasons also had something to do with this. Even Kathy, my wonderful but non-audiophile (whimper!) wife, noticed how much acoustic guitars sounded like acoustic guitars on Lynyrd Skynyrd’s all acoustic CD, Endangered Species. This particular CD can sound edgy, hard, and strident on lesser CD Players, but it doesn’t on the CD2. At the same time, the detail is not lost. On Cheryl Wheeler’s CD, Driving Home, the triangle on track one sounds more like a triangle than I’ve heard it sound on any other digital front end.

Although the CD2 comes closer to analog than most digital, it still does not match the best of the digital front ends in a few areas:

1) It lacks ultimate smoothness and refinement, but it is better here than most in its own price range.

2) The bass is not as tight as it could be. In this price range, extremely tight bass is associated with that "lean and mean" sound. To get extremely tight bass without being "lean and mean", it seems one has to spend substantially more money. Happily, the CD2 does not sound lean and mean.

3) Although good, the dynamics could be better. It is possible to get better dynamics for less money, but not without sacrificing the more important things that the CD2 does so well, such as tonal balance, soundstaging, and non-aggressiveness. Some of the megabuck digital front ends that better the CD2 in these three areas fall short of it in overall resolution, imaging, and soundstaging.

The sound of the ARC CD2 can be improved by tweaking. By a very large margin, the thing that made the biggest improvement was changing from the stock power cord to the Synergistic Research A/C Master Coupler. I tried two other high tech power cords, but the Synergistic was substantially better. The different power cords had their own distinct sonic signatures and made major differences in the tonal balance — especially in terms of bass weight.

I would hesitate to recommend buying any expensive power cord without an in-home trial, so please use my comments as a guide, and not as a substitute for your own ears. In my listening room, here is a list of the positive effects of the Synergistic power cord: a more natural treble; more natural timbres; better extension at the frequency extremes; tighter, clearer bass; an overall smoother, cleaner texture; better pitch definition in the bass; better soundstage depth; a stronger sense of the musicians being in the room with you; and substantially better imaging overall. (This despite the fact that, in one instance, it made a female vocal sound a bit unfocused.)

The CD2 is also slightly sensitive to placement; it sounds a little better on a shelf in the middle of my component rack than it does sitting on top of the rack. I don’t know if this was vibrationally related, or if was caused by cable routing or proximity to other components.

The last tweak I tried was to put some support cones underneath the CD2. These did more harm than good. I even tried them upside down, and that was dramatically less successful.

It is the current trend to make remotes and computer mice with extremely rounded surfaces, and the CD2’s remote is no exception. Ergonomically, the old box-like shapes were more friendly, in my opinion. Having had unsuccessful surgery on both wrists, this is important to me. The flat, straight up and down sides of the box-like shape give those of us with bad tendons in our wrists a nice large gripping surface that requires less grip strength from painful tendons. Those makers of remotes and computer mice who followed the current trend of excessively rounding the surfaces, and who sacrificed ergonomics for the sake of visual aesthetics, are hereby chastised. One other point on the remote for the benefit of those audiophiles who own an ARC preamp with a remote control, the CD2 remote should have volume up and volume down to allow for the use of just one remote. It doesn’t.

Some might complain that the CD2 does not have HDCD. I don’t know if this is typical, but I have hundreds of CDs and only one of them is HDCD encoded, so I just don’t give a (insert your favorite phrase about a rodents posterior body part here) about the lack of HDCD decoding. [Nevertheless, Ye Olde Editor notes that if HDCD™ is important to you — there are, after all, quite a number of CDs out there now that are produced to this standard — you would have to make other arrangements.]

The CD2 has a differential bitstream (delta-sigma) D/A decoder with 20-bit resolution, and the analog output stage is fully differential, direct-coupled, and uses both J-FET and bipolar transistors with regulated supplies. The digital outputs have high-stability, crystal-controlled re-clocking and include TOSLINK, coaxial BNC, balanced AES/EBU on XLR, and optional ST glass fiber.

Balanced Analog Output: 4.2V RMS, 350 ohms
Single Ended Analog Output: 2.1V RMS, 175 ohms
Frequency Response: 0.1-20,000Hz +/- 0.2dB
Signal To Noise Ratio: 96dBA
Distortion: -90dB (0.003%) 1kHz
Channel Separation: 100dB 1kHz
Phase Linearity: +/- 0.5degrees 20-20,000Hz
Wow & Flutter: Unmeasurable.

When I was nearly done with this review, I called Audio Research to see if there were any design specifics that I should mention. When I talked with Warren Gehl and Rich Larson, I was told that ARC always pays a lot of attention to power supplies. Specific to the CD2, they both mentioned the engineering for control of mechanical resonance. The resonance damping in the CD2 is quite extensive. They used seven different proprietary damping materials, and pads on the crystal and on the ICs. There is constrained layer laminate polymer damping all over the place. The transport is damped, and the transformer decoupling grommets are tuned. I’m told that all this damping is responsible for the focus and the quiet background. I tapped on the CD2 with my knuckle, and it sounded dead. The metallic ring that I heard when I tried this on some of my other components was absent.

Conclusion

I’m very much enjoying the ARC CD2 in my system, and I highly recommend it. To summarize my impressions in this review: The CD2 is non-fatiguing. The tonal balance and the instrumental timbres are excellent, and its imaging and soundstaging are exemplary. The dynamics are fairly good, and the music is extended in both frequency extremes. The CD2 resolves treble detail better than some of the megabuck digital separates.

There is only one shortcoming: the bass isn’t as tight and dynamic as it could be. I’m not saying that the bass is bad in these respects. In fact it’s fairly good, but this is the area where I think it differs the most from the best of the megabuck digital front ends. After two weeks of breaking in on continuous repeat, followed by over a month of fairly heavy use, my impression is that the bass is still slowly improving. The bass is not lacking for weight, and it does not sound woolly. However, if an extremely tight bass is at the top of your sonic priorities list, then you might reach a different conclusion than I did. Nevertheless, if the $3,495 price is in your range, you should still consider adding the ARC CD2 to your audition list because of all its other excellent qualities.

I do like the idea of a "single box" CD Player, as opposed to a separate transport and DAC. You do save money by not purchasing the second chassis and the interconnects, you don’t have to concern yourself with jitter, and having just one box is simpler and less cluttered. When you can get this kind of quality from a single box, it seems almost like a no-brainer.

Associated equipment:
Speakers: B+W 802 series II
Subwoofer: Audio Pro B2-50 (this was hooked up about half the time)
Preamplifier: AGI 511a (heavily modified)
Amplifier: Mesa Engineering Baron
Integrated Amplifier: Mesa Engineering Tigris (review sample)
Turntable: Bang & Olufsen Beogram 1700
Cartridge: Bang & Olufsen MMC 20 EN
Interconnects: Transparent Musiclink Ultra, MIT MI 330
Speaker wire: Discovery 123

Audio Research Corporation
5740 Green Circle Drive
Minnetonka, Minnesota 55343-4424
(612) 939-0600

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