AV preamps and receivers have become overly complicated affairs, offering up features and connectivity that would've been science fiction twenty-five years ago. Meanwhile, two-channel preamps have been left largely in the dust, performing much as they have for the past century. With the proliferation of digital music, especially iTunes and other downloadable music files, two-channel DACs (digital to analog converters) have experienced a resurgence, but two-channel preamps have remained the same - until now. Enter Classe's newest two-channel preamp, the CP-800 stereo preamp processor, a $5,000 no holds barred two-channel preamp that packs a few bells and whistles normally reserved for its AV counterparts. Could the CP-800 be the first in the evolution of the stereo preamplifier? That's what I wanted to find out.
• Read more stereo preamp reviews written by the staff Home Theater Review.
• Learn more about The Evolution of the Two-channel Preamp.
• Find a pair of Bookshelf Speakers or Floorstanding Speakers to pair with the CP-800.
The CP-800 replaces both the CP-500 and CP-700 preamps from Classe. From the front, it doesn't look all that different. The CP-800 is clad in Classe's now-trademark white fa�ade with black accents surrounding its touch-screen controls and large volume knob. The CP-800's edges round delicately towards the rear of the unit, giving it a modern architectural flair that is unlike anything you'll see elsewhere in high-end audio. The CP-800 is nearly five inches tall and 17.5 inches square, tipping the scales a solid but not unruly 23 pounds.
The front of the CP-800 sports a traditional headphone jack as well as a USB input, both of which rest between the left-mounted touch-screen and right-positioned volume knob. The touch-screen is a two-color affair, but the CP-800's screen has traded black for blue and left the white alone. While the combination of white on blue may seem odd or, worse, difficult to read, rest assured, it's not - in fact, it's quite pleasing and easily read from some distance (12 feet for me).
As futuristic as a touch-screen may be, it's when you focus your attention on the CP-800's rear panel that things begin to really take shape. Moving left to right, the first things you'll notice are the CP-800's master power switch and detachable AC power cord, next to which rest its nine digital inputs. Wait, what? That's right, the CP-800 has nine digital inputs: four optical, three coaxial, one AES/EBU and a second USB. All nine digital inputs feed the CP-800's all-new DAC, which when used with either of its two USB inputs will provide more than just your average run of the mill conversion. More on this in a moment. To the right of the CP-800's digital inputs are its various IR, trigger and control ports, which include RS-232 and Ethernet (forthcoming), among the other more traditional 12-volt varieties. Along the bottom, again moving left to right, are the CP-800's five analog audio inputs, three unbalanced and two balanced, all of which are assignable by the user. To the right of its analog inputs are the CP-800's five analog outputs, both unbalanced and balanced, which, like its analog inputs, are all user-configurable. How user-configurable? The CP-800 can accommodate multiple subwoofers as well, or multiple amplifiers in a bi-amp configuration, or both, making it the ideal preamp for those who enjoy full-range two-channel playback, as well as the occasional DVD or Blu-ray disc.
Under the hood, there are a number of major advancements unique to the CP-800 and to Classe. First there's the CP-800's Switch Mode Power Supply (SMPS), which is smaller and more efficient than conventional power supplies. The SMPS inside the CP-800 has four separate outputs: one for left and right audio circuits, one for the digital circuits and one for the USB system, which allows for connected USB devices to charge while plugged in.
Speaking of USB, the CP-800 is an Apple-certified device. Its front-mounted USB input enables not only full playback of Apple music files, but also charging capabilities. The included CP-800 remote can also access and provide simple transport control of any Apple-attached device, thanks to the 800's Apple authentication chipset. Connecting your home computer to the CP-800's rear USB port also allows for the proper playback of music files from any player. Taking things a step beyond mere Apple certification, the CP-800's USB performance is further enhanced by the isolation of the USB circuit itself. The CP-800 also employs what is referred to as an asynchronous USB DAC, whereby the jitter-induced by one's computer or portable digital device is effectively removed by not having the source be responsible for the clocking of the incoming signal. This ensures not only a more accurate and natural portrayal of the digital signal, but also reduces noise - another byproduct of both the CP-800's asynchronous DAC and USB circuitry isolation. The CP-800 uses what is called a Field Programmable Gate Array (FPGA) located close to the DACs and master clock that essentially takes the incoming signal and buffers it before sending it along to the 800's master clock, which is synchronous to the internal DAC. Either of the CP-800's two USB inputs can take advantage of the new asynchronous DAC setup.
Beyond its built-in DAC capabilities, the CP-800 also features pretty robust tone controls, as well as bass management and parametric EQ. Since most users will undoubtedly connect their various source components to the CP-800 via some form of digital connection, the tone and EQ controls are able to be tackled in the digital domain. Furthermore, because so much of the CP-800's abilities are dealt with in the digital realm, it keeps the internal signal path short, thus preserving more of the signal, rather than passing it along through a bevy of third-party components or cables.
This brings us to the CP-800's remote, which I feel also doubles as its theft deterrent stick, as it is forged out of aluminum and weighs more than any remote I've encountered. The remote is fully backlit, feels good in hand and is easy to use, though for initial setup, you or your Classe dealer will most likely use the CP-800's touch-screen.
Unboxing the CP-800 and placing it in one's rack is easy enough. Making the requisite connections is equally pedestrian, which my case involved connecting my Cambridge Audio Azur 751BD Blu-ray player to the CP-800 via an optical and coaxial digital cable, both of which were generic in make. I ran a separate set of Transparent Cable analog interconnects from the 751BD's stereo analog outs to the CP-800's analog inputs in order to test its analog performance. To test the CP-800's USB capabilities, I used my iPhone as a transport playing a bevy of digital music files, ranging from 256K to uncompressed, which were sent to the Classe via Apple's own iPhone to USB cable that comes free with purchase.
I initially connected the CP-800 to my review sample Pass Labs X250.5 stereo amplifier. However, in order to test the 800's flexibility and bi-amp capabilities, I later substituted in my Parasound 5250 v2 multi-channel amplifier, with channels one and two powering the right speaker and channels four and five powering the left. As for speakers, I relied solely on my reference Bowers & Wilkins 800 Series Diamonds, which I connected to my amplifier via four runs of Transparent speaker cable.
I used my two JL Audio Fathom f110 subwoofers to augment the 800 Diamond's bottom end. Since I use an outboard parametric EQ for both subwoofers, transferring that information to the CP-800's internal parametric EQ was easy enough. However, my reference EQ setting uses seven filters, whereas the CP-800 limits you to only five. With some help from Room EQ Wizard, a free downloadable program, and Home Theater Equipment forum member RayJr., I was able to come up with a new curve that closely matched that of my reference, using only five filters. In a direct A/B comparison between my reference filter and the modified one used for the CP-800, the difference was negligible. Once I had the parametric EQ inside the CP-800 dialed in, it was simply a matter of telling the preamp which input was which, which EQ and bass management settings to apply to each, and identifying that the remaining two auxiliary outputs were to be used for amplification and not for additional subwoofers. In order to run two subwoofers and still have the requisite outputs for bi-amping, I had to run the subs as a summed mono pair, meaning they were fed the same signal, only split between the two. If you want to run true stereo subwoofers out of the CP-800, you can. However, it makes true bi-amping impossible.
From unboxing to final install, it took several days, due to a lot of experimentation and evaluation. However, you could easily have the CP-800 installed in your system in less than an hour if you were strictly attempting to utilize it in a plug-n-play configuration. That said, if you are a plug-n-play type of user, may I suggest you look elsewhere, for the CP-800 isn't going to be for you - it's a preamp for those who are willing to sit down and make sure everything in their system is operating to 11. Take the time to get everything just right and the CP-800 will reward you handsomely, though don't be surprised if, down the road, you discover a setting or configuration option you didn't notice or rejected at first but now find preferable. To quote my friend, "The CP-800 is a product you 'grow' into."
I honestly don't listen to a great deal of music via USB connected devices. However, I feel that in the future I will, so to become more accustomed to the sound, I started my evaluation of the CP-800 with its USB inputs. In order to properly compare and contrast the 800's USB capabilities with that of its other digital abilities, as well as its analog, I used a track that I was intimately familiar with, Diana Krall's "A Case of You" off her album Live in Paris (Umvd Labels). I used the CD itself to make several rips of the track, one at the iTunes standard 256K, one in Apple's own lossless compression and lastly the disc itself. I loaded the two MP3 files onto my iPhone and connected to the front USB input on the CP-800.
Read more about the performance of the Classe CP-800 on Page 2.
Beginning with the CD itself played back via my 751BD, which was used as a transport only, the song was realistic in its overall portrayal, with natural tone and dynamics that go along with a quality audiophile recording. Krall's vocals were lifelike in their scale, weight and focus, as was the surrounding air that seemed to encapsulate the space, not only around her, but also around her piano. Speaking of the piano, its position within the soundstage was firm and focused and the level of texture and detail contained within was impressive, to say the least. The remaining instruments were rendered with equal fervor, especially the double bass, which was plucky and deep, not to mention appropriately sized and placed within the soundstage. The soundstage itself was wide and as deep as I've come to expect, and the focus and spacing within remained unchanged.
It was at this point that I began to get an overall sense of the CP-800's sound, or should I say lack thereof, for the presentation was similar (although not the same) to that of my Wyred 4 Sound DAC-2, which has a digital volume control, should you want to use it as a digital DAC/preamp.
I found the CP-800 to be just as transparent as the DAC-2, imparting little if any sound of its own to the incoming source material, which is a good thing in my book. Instead of sweetening the midrange, accentuating the treble or boosting the bass, the CP-800 seemed to only bring about the slightest hint of added air, space and textural detail to the source material. Upon closer listening and A/B tests with other preamps I had on hand, I found the CP-800, via its digital inputs, simply presented the music as if through a more refined microscope, with minor details, nuances and inflections more apparent than those of other preamps that I had on hand. In switching amplifiers, I found it easy to gain a truer sense and appreciation for the amplifier's sound. However, the CP-800 did little, if anything, to alter it. The CP-800's neutrality proved to be a trait I've associated with another Classe preamp, their flagship Omega MKIII Preamp.
Wanting to make doubly sure of the CP-800's lack of house sound, I went ahead and played the same Diana Krall track via my 751BD player, only this time I bypassed the 800's DACs in favor of the ones inside the Cambridge player. Connected to the CP-800 via a pair of analog interconnects, the 800's analog sound was again largely neutral, for the slight warmth, low midbass hump and smoothing of the treble I heard was consistent with previous tests I had done with the 751BD used not as a transport, but rather as a digital player. As in my tests utilizing the CP-800's internal DACs, there was still a sense of greater dynamics, detail, texture and focus present when compared to other preamps I had on hand. The differences may have been subtle, but they were nevertheless audible.
Turning my attention to the CP-800's USB inputs, I played the same track, beginning with the lowest-resolution rip. Surprisingly, the resulting performance wasn't terrible, in fact it wasn't even bad - it was enjoyable. Minus some slight spatial flattening, a bit of top-end grain and some dynamic compression, the low-resolution rip of "A Case of You" was not night and day different from that of its full-resolution CD counterpart. Cuing up the Apple lossless encoded version proved to be even more eye-opening, for I found it difficult to discern any difference between the rip and the full-resolution version. Using my wife's MacBook laptop as a source connected to the CP-800 via its rear-mounted USB input only furthered not only Classe's claims surrounding their DAC's USB prowess, but also my findings that lower-resolution music need not be the stuff of nightmares, and that properly ripped digital music is all but indiscernible from its CD counterpart.
In order to then test the CP-800's other attributes, specifically its tone controls and parametric EQ, I fired up Dave Matthews Band's "Dancing Nancies" from their album Under The Table And Dreaming (RCA). The opening features a very well-recorded drum kit, which accompanies Matthews' vocals. When the kick drum enters the fray, the CP-800's bass was palpable with a sort of kick-you-in-the-chest focus and attack that is difficult to describe, let alone replicate, without some form of EQ, at least in my experience. With my slightly adjusted curve loaded into the 800's internal parametric EQ, the bass via the CP-800 possessed that same kick-you-in-the-chest impact. Disabling my EQ settings and hitting play again was all the proof I needed in determining the 800's parametric EQ's effectiveness. When it was disengaged, the bass was bloated, slow and not at all refined. Even when comparing it to the single-band auto-EQ found inside the JL subs themselves, the difference was night and day, with the victory going to the CP-800. The fact that the CP-800 allows you the ability to incorporate not one but multiple subwoofers is further testament to its overall utility.
I ended my evaluation of the CP-800 with a Blu-ray demo of the pop musical Burlesque (Sony Pictures) starring Christina Aguilera and Cher. With my 751BD doing the decoding and stereo down-convert, all I had to do was run a separate HDMI cable to my Panasonic plasma and I was in business. Skipping to Chapter 10 and the musical number "Express," I utilized the CP-800's tone controls to take a bit of heat off Aguilera's vocals, which are a touch hot during this particular performance. A slight negative two-dB adjustment to the treble proved all that the doctor ordered in calming the majority of the track's sibilance and high-frequency harshness, which allowed me to simply go on and enjoy the show. Despite not having a center channel, or rears, for that matter, the CP-800's portrayal of Burlesque was exquisite. The music virtually surrounded me, though all the while remained focused and nuanced in its presentation. The bass was prodigious, no doubt aided by the CP-800's EQ, which was engaged for this demo.
Truthfully, it was during my demo of Burlesque that the CP-800's true value came into focus, for it proved to be as adept at two-channel playback as it was at multi-channel fare, despite not having actual multiple channels to command. Because of its neutral stance on everything, the CP-800 is a true maestro of all that is presented to it and, thanks to a bit of techno wizardry, it can also serve as the command center of a versatile 2.1 channel system, one that may have an audiophile DNA structure but isn't afraid to go to the movies on a Friday night.
Competition and Comparison
While it would be easy for me to compare the CP-800 to simple two-channel preamps, it wouldn't be fair - to the other preamps. The CP-800 is oh so much more than that. The truth of the matter is that there simply isn't another preamp like the CP-800 currently on the market. There are a few coming, but currently the 800 is the star and sole guest at its own party.
McIntosh makes two preamps, the C50 ($6,500) and C48 ($4,500), which look to capture a bit of the CP-800's magic through the inclusion of built-in DACs and multi-band EQ, but neither have feature sets as robust and/or implemented to the same degree as what you'll find in the CP-800. Still, it's nice to see a brand like McIntosh progressing out of the dark ages of audiophilia with such products.
NAD will soon have a digital preamp for sale that will also compete with the CP-800, though it lacks the bass management, EQ and versatility of the Classe product. Then again, it will retail for $2,000 and have HDMI connectivity, which the CP-800 lacks.
Krell has a new preamp on the way in the form of their $5,000 Phantom III and it should have a lot of the versatility of the CP-800, though I'm told it will lack the 800's bass management and EQ capability.
Lastly, there's Mark Levinson and their yet-to-be-released No 560 digital preamp, which will retail for $6,000 when it is released later this year. Like the Krell, McIntosh and NAD preamps, the No 560 will lack some of the features found on the CP-800.
For more on these preamps and others that are a bit more traditional, please visit Home Theater Review's Stereo Preamp page.
It's hard to fault the CP-800 for no other reason than that comparison is so far impossible. Until its release, we haven't had a preamp like it. That said, there were a few items that were worth pointing out. First is the CP-800's lack of any sort of video output. I know that may sound out of bounds, but when your two-channel preamp has the sort of connectivity and options list usually reserved for an AV preamp, a little on-screen GUI isn't required, but it would be nice.
Sticking with video for a second, I slightly cite the CP-800 for its lack of HDMI connectivity. I know it isn't an AV preamp, but because of its bass management, EQ and DAC capabilities, it's a prime candidate to be the centerpiece of a 2.1-channel system, which I have to imagine might include HDMI. The soon-to-be-released NAD has HDMI connectivity and, at $5,000, believe it or not, I think the CP-800 should, too.
The CP-800's parametric EQ is phenomenal and truly a nice touch, but it is limited to five bands. This may not sound like a problem, but when you're used to utilizing parametric EQ and your curves require more filters, the 800 does force you to make some compromises. In all fairness, the difference between my reference curve and the one I had to use for the 800 resulted in the subtlest change in my system's bass response, but for those who insist upon absolute perfection, the 800 may not have the control - at least within its EQ - that is demanded.
Lastly, and this is most likely the strangest downside I've ever written about, I'm not sure the CP-800 is for everyone. I say this because the CP-800 is more than just the mere plug-n-play, two-channel preamp that is familiar to many an audiophile. Because of this, I doubt many will use it to its full potential, which is a shame, because it really is a versatile piece, one that you could easily discover new things about months after purchase. If you're in the market for a truly full-featured preamp and want one that is going to grow with you and your system, then by all means audition the CP-800, even if you don't fully understand all of its various features. Just make a promise to yourself that, should you buy it, you'll take the time to learn it.
The final question that has yet to be answered: is the CP-800 stereo preamp processor from Classe worth it? In a word, yes. In two words, hell, yes. While I know some may look at its $5,000 retail price and shake their heads and call me crazy, consider this. In an attempt to match the Classe's performance in my system I needed four, count 'em four, separate components at a cost of around $5,000 before I was able to approach (note that I didn't say match) the capability and sound quality provided by the CP-800. So is the CP-800 a value-oriented product? I think so, for Classe could've easily charged more, but they didn't and I respect them more because of it. Sure, there are going to be haters out there, but allow me this one last point in defense of not only the CP-800, but also my affinity for it.
My last reference two-channel preamp was another Classe piece, their flagship Omega Pre-Amplifier MKIII, which at $17,500 is among the most expensive preamps I've ever hosted. I lived with the Omega MKIII for nearly a full year, utilizing it each and every day and loving every second of it. I almost went so far as to make it my very own, that's how strongly I felt about its performance. As I write this, I'm glad I didn't, for as taken as I was with the Omega MKIII, I consider the CP-800 to be its superior in every conceivable way.
That is why, as of this review, I have to call the CP-800 the best two-channel preamp I've heard to date. While there are more than a few competitors coming down the pike, I don't think that the CP-800 will be upset any time soon. If you're in the market for a truly high-tech and high-end stereo preamp, I urge you to audition the CP-800, for not only do I think the 800 will blow your mind, I also believe it may be the last preamp you will ever buy.
• Read more stereo preamp reviews written by the staff Home Theater Review.
• Learn more about The Evolution of the Two-channel Preamp.
• Find a pair of Bookshelf Speakers or Floorstanding Speakers to pair with the CP-800.