| Products in this article: | Halo P7 multichannel preamplifier |
| Related products: | Parasound Halo P7 multichannel preamplifier Marantz America AV8003 THX Ultra2-certified A/V Pre-Tuner |


An Important Note for Playback Readers: As with many of my articles, this is an exploration of how sound systems work and how we perceive sound as much as it is a review of the components at hand.
I have for some time been interested in preamps, and specifically multichannel preamps. The reasons for this interest arise from some basic questions.
For about a decade I have assumed that the ideal music playback system would be multichannel. I figured that multichannel music would become a mainstream option. I also figured that a lot of us would want to use our music systems for movie playback (with a sizeable investment in multichannel audio for music I had no interest in spending more for a separate home theater rig). Because of the limited availability of multichannel music, this vision isn’t exactly happening, though of course some people still respond to the economic argument. And classical fans do have a good choice of MC SACDs. This review will tackle several key questions.
Question 1: If you take MC sources seriously, are there good MC preamps available as measured by traditional two channel audio standards?

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The other element of my fascination with preamps comes from my sense that the preamp is a very simple device that shouldn’t make much difference. Or, said differently, it should be pretty easy to design a nearly perfect preamp and thus they should be readily available at affordable prices. Problem is, my experience is that preamps matter quite a bit and unfortunately the best examples are expensive. Hence, a second question.
Question 2: Do preamps really differ meaningfully from each other, and if so how?
To address both questions above, I decided to review and compare two very good but conceptually dissimilar multichannel “front end” components. I gathered up the Parasound Halo P7 multichannel preamplifier, because Parasound Halo-series components enjoy a great reputation for delivering good sound at reasonable prices ($1999 in this case). I also obtained a Marantz AV8003 multichannel A/V controller because I wanted to see whether a full-on digital processor could play in direct comparison with some serious high-end audio big boys. I chose the Marantz because it pays attention to audio matters yet doesn’t break the bank at $2599.
For comparison purposes I also brought along two very highly regarded, purist two-channel preamps that I own: the mbl 6010D ($23,800) and the Audio Research LS26 ($5999). I conducted most of my listening in two-channel mode because I wanted to understand where, if anywhere, the multichannel gear gave ground to premium two-channel gear.
Consider this multichannel preamplifier if: you want a multichannel version of a traditional stereo preamplifier (that is, a preamp with an all-analog signal path), and your musical priorities tilt toward delicacy and nuance.
Look elsewhere if: you need full home theater surround sound decoding features, onboard video switching/processing features, etc.
Ratings (relative to comparably priced analog multichannel preamps)
Consider this A/V Pre-Tuner if: you want a full-function A/V processor whose preamp section easily competes with traditional two-channel audio preamps at or above its price.
Look elsewhere if: the complexities of full-fledged home theater processors and remotes are an annoyance to you.
Comments
It is interesting--and telling--that the audio quality of well-made mid-market electronics (Marantz) is now equaling the higher-priced "purist" high-end products (Parasound)--and you get a lot more flexibility to boot. The idiosyncratic sound of the Audio Research is very troubling--if it sounds "different", I doubt that it can be better, since the principle of high fidelity performance is that all the competition should be sounding more similar the more accurate they become. If this trend continues (better quality mid-market products, escalating prices of high-end products), it simply won't be cost-effective to buy high-end products anymore except for the snob appeal.
Ron Levine
Philadelphia
Your comparisons echo the comments I made about the AV8003 on Amazon's web site yesterday. A friend of mine, after reading my comments, questioned whether or not I was being completely objective in my opinion that the analog section of the AV8003 is as good as those on some very high end 2-channel preamps that I've auditioned. I told him that absolute objectivity is difficult (as I own an AV8003) and that I might be justifiying my purchase in my own mind but that I felt I was being honest in my evaluation. Your article lends some credibility to my earlier assertion. I can hardly wait to hear his reaction to it.
I'm not sure how your unit was configured, but I've discovered that CD playback using the analogue out from either my Marantz DV9600 or Oppo BD83 and selecting Pure Direct mode on the AV8300 produces a sound that is hard to beat in my book.
Theoretically, a preamp should do nothing to the original signal other than possibly add some gain before sending it on to the amplifier so one would expect more similarities than differences amongst the various designs. Apparently, there is not a lot of differences in gain stages of preamps? The real differences in controllers become more apparent when they are performing D to A conversions, as there seems to be detectable differences in the various chipsets and implementations.
As a side note, I prefer the audio from theMarantz player over the Oppo in the described configuration although they both sound very good.
This is probably just my personal perception but when there is a review of something like a pre-amp it would seem nice to mention the amps that compliment or have been used to define these products along with any other equipment in the chain between the source and the listener? Did I miss this?
I wound up retunring two different P7s becasue they had an identical hashy noise coming from one channel from balanced outputs. Yes, I was careful to isolate it to the P7 by changing channel connectors from the sources and also to the amp. They were several hundred apart in serial number, so I wonder if this is some kind of weird problem they have. Was not present from the unbalanced outputs. Was quite evident from my high efficeincy Genesis speakers, but lower efficiency Soundlabs did not suffer to anywhere near the same degree.
I've owned the P7 for about 2 months, and have had the AV8003 for almost a week, with lots of listening hours on both. No conclusions yet, but did want to share that I initially heard the same sibilance referred to in the article ("emphasized the leading edge of treble sounds") in the P7. It was especially noticeable on the front edge of brass notes. All that said, it went away about a week or two. As an orchestral musical, I'm very fussy about accurate tonal quality, and I would have sent the unit right back had it not resolved.
If there’s interest, will post more after reaching conclusions.
This review was informative,but will there be a full review as a Surround sound processor?
I noticed the P7 has a phono preamp and the Marantz does not. Might make a difference to some.