Parasound Halo P 5 2.1-channel D/A preamplifier

Asked how to make a guitar, the celebrated luthier Wayne Henderson offered a straight-up answer: "Just get a pile of really nice wood and a whittling knife. Then you just carve away everything that isn't a guitar." (footnote 1)

The making of a preamplifier seems more or less the opposite. You start with a simple volume control and a couple of jacks, then add whatever you think constitutes a preamplifier. Choices might include electronic source switching, line-level gain, phono-level gain and equalization, tone controls, tone-defeat switches, a balance control, a headphone jack, an iPod input, and maybe even a digital-to-analog converter with a USB receiver. The sky is pretty much the limit.

Asked what constitutes a preamplifier, the California-based electronics company Parasound might simply copy the preceding paragraph: The newest preamp in their Taiwanese-built Halo series of products, the Halo P 5 ($1095), incorporates every one of the items mentioned above. And, remarkably, a few more.

Description
Parasound describes the Halo P 5 as a "2.1-channel stereo preamplifier," hinting at its suitabilities for use in both a stereo music system and a home theater. The latter is presented in a number of ways, the most apparent being its home-theater bypass circuit, by means of which one can add the P 5 to a multichannel system with a surround-sound receiver or processor, to optimize two-channel listening (footnote 2). (For this to work, the surround-sound component in question must have line-level outputs.) Usefully, whenever the P 5 is switched off, its home-theater bypass is automatically selected, so that the surround-sound system can still be enjoyed without additional drudgery.

414para.bac.jpg

Also of interest to home-theater enthusiasts, the Halo P 5 has line-level outputs for up to three powered subwoofers—the third output is an XLR socket for balanced connection—all of which present the same mono signal and are controllable by means of a front-panel subwoofer level control. Additionally, the P 5 includes an analog crossover comprising a low-pass filter for the sub(s) and a high-pass filter for the main outputs. Both filters are user-controllable by means of small potentiometers on the rear panel, each with a range of 20–140Hz. The crossover's usefulness, of course, is limited to systems whose subwoofers include defeat switches for their own, internal crossovers; perhaps needless to say, the P 5's subwoofer filters are switchable.

414para.bac2.jpg

Otherwise, the Halo P 5 is optimized for serious music listening, right down to its front-mounted bass and treble tone controls, and a tone-defeat switch for removing them from the signal path. The front panel also sports a nice-feeling rotary switch for source selection, accompanied by a clearly marked row of indicator lights, and an exceedingly smooth, undetented volume control. I was mildly disappointed by the lack of a mono switch but cheered by the presence of a 3.5mm input jack, the latter tailored, by means of an extra gain stage, for use with the analog output of an iPod or similar device. And although I own neither a balanced-out source component nor a balanced-in amplifier, I was impressed that the Halo includes a single pair each of balanced input and output jacks.

The use of a switch-mode power supply—and the consequent absence of a traditional mains transformer—accounts for the P 5's most surprising characteristic: Notwithstanding its abundance of features, its moderately sized case is almost half empty! Beyond that, there's precious little I can tell you about its innards, other than the fact that its seven circuit boards appeared well made. The P 5's casework is nicely done, with a mix of steel and aluminum structures and a textured finish that gives, from a moderate distance, the impression of a high-tech casting. Cosmetics and ergonomics alike were of higher-than-expected quality for this price bracket.

Installation and setup
Owing to a combination of well-labeled controls and a notably clear instruction manual, the Halo P 5 was a breeze to set up. Adding to that ease was the simplicity of this particular installation: I, who own neither a subwoofer nor a surround-sound component—or even a television set that was made in this century—was offered the chance to review the P 5 as a two-channel product in my two-channel system. The remaining 0.1 channel must await another day and another writer.

That said, two aspects of the Halo P 5's operation do require special mention, the first being its built-in D/A converter, which is addressable by means of optical, coaxial, or USB connections. With either of the first two choices, the Parasound DAC functions at word lengths and sample rates up to 24 bits and 192kHz, respectively (the chip at its heart is Burr-Brown's 24-bit, 192kHz-capable PCM1798 DAC), but offers only 24/96 performance when the incoming datastream arrives by USB.

The P 5's converter compensates with an exceptionally easy-to-set-up USB connection: Even Windows users should be able to get up and running in just a few minutes, without having to download a separate device driver. My own iMac installation was simplicity itself: In the Sound window of Apple OS10.7.4's System Preferences, the P 5's built-in DAC appeared with the name "PARASOUND P5"; one click was all it took to get me up and running, after which my computer never ceased to recognize the Parasound converter.

Vinyl lovers will also require an extra minute or two to get going, as the P 5's single pair of phono inputs can be optimized by means of a three-position toggle switch on the rear panel. Two of the three settings are intended for moving-coil cartridges—one provides a load impedance of 100 ohms, the other 47k ohms—while the third setting, for moving-magnet cartridges, also offers the 47k ohm load. Although phono-section gain is not specified in either the P 5's manual or on Parasound's website, I noted that both MC settings provided more than enough gain for my EMT TSD 15 pickup head, which outputs 1.05mV.



Footnote 1: From Clapton's Guitar: Watching Wayne Henderson Build the Perfect Instrument, by former Stereophile record reviewer Allen St. John (New York: Free Press/Simon and Schuster, 2005).

Footnote 2: Perhaps some day there will exist a very high-quality mono preamplifier that incorporates a stereo bypass circuit.

COMPANY INFO
Parasound Products, Inc.
2250 McKinnon Ave.
San Francisco, CA 94124
(415) 397-7100
ARTICLE CONTENTS

COMMENTS
otaku's picture

The remark about "carving away everything that does not look like a guitar" is not very original.

"Struggling to emerge from the brute marble, they remind us that Michelangelo is supposed to have said that he simply 'carved away everything that wasn't the sculpture'."

http://online.wsj.com/news/articles/SB10001424127887324374004578219664085863282

John Atkinson's picture

otaku wrote:
The remark about "carving away everything that does not look like a guitar" is not very original.

If you click on the link in the footnote to my review of the book on Henderson's guitars, you will see that I did say: "Most important, the reader is exposed to how a guitar can be made by someone who echoes Michelangelo by merely removing the excess: sawing, scraping, whittling, and sanding away from a pile of raw lumber everything that isn't a guitar."

John Atkinson

Editor, Stereophile

yaka24's picture

It would be great to have a review of Emotiva XSP Gen 2 to compare this to. Same price range, similar features. 

Eddie Currents's picture

This is a bit off topic but owing to the fact that it probably never will be a Stereophile topic I decided to post it anyway.  On page 106 of the May 2003 issue of Hi-Fi World, David Price had some nice things to say about what must be the most unloved piece of audio equipment ever (no it's not an equalizer) - the servo controlled Japanese linear tracking turntable of the 1980s.  Scratching a senior citizen itch I bought one (Technics SL 5) on eBay and after getting over the shock that it worked at all, I was amazed by its performance (and I'll just leave it at that). Price talked about the SL 10 but says the 7 is the one to look for.  Ortofon makes a high input MC P-mount cart and LP Gear sells an MM with a Shibata stylus.  Maybe Art could find one at a yard sale, clean it up, take a listen and prove that it's not just the Brits who have an open mind.

Muzicianx's picture

Mr. Dudley - 

I really must ask why you were given the obvious chore of reviewing the P5.  You did not integrate it into a surround sound system, you did not use a subwoofer, you did not try the balanced connections, nor did you try it with an amp that might suit this particular preamp - say the A23, or modest counterpart.

I'm super excited that the phono stage is adequate, and surprised about your reactions to the DAC (glad to hear the positivities), but it would have been nice for this thing to be run through it's courses, as I can't be the only one seriously looking to buy, and integrate it in a critical listening environment.  

I know, try it for myself, listening is speculative, but this review is about as vanilla as it gets.  At least Audio Advisor has a trial period!

John Atkinson's picture

Muzicianx wrote:
You did not integrate it into a surround sound system...

Even if the Halo P5 has a home theater bypass function, it is not a surround-sound component.

Muzicianx wrote:
you did not use a subwoofer, you did not try the balanced connections...

Those aspects of the P5's performance were fully covered in the Measurements section.

Muzicianx wrote:
nor did you try it with an amp that might suit this particular preamp - say the A23, or modest counterpart.

Guilty as charged. :-)

John Atkinson

Editor, Stereophile

R2D2's picture

Hi, I am in between the Parasound Halo P5 or the Nad C165Bee. This will be used for vinyl cd/SACD only. Which one Do you think suites better? It is going to be used with a 50-70 watt Nad or Parasound amplifier and a pair of Atlantic technology At-1 or AT-2's.
If I'm going for an integrated system, I like the Arcam A19, Creek 50A or the Yamaha A-S2000. Would you go for a separate or an integrated system taking into consideration the ones listed here? Do you think this would make any sound improvement over my current sound system: Nad 326bee, Nad 245bee 4 channel amp (for biamping a pair of PSB's Image T6), Nad C446bee cd player, Nad C446 media streamer and a Musical Fidelity M1DAC?
Thanks for your help...

sumitumi's picture

Does it allow airplay?

KeithWrites's picture

my current plan is to actually use this unit as designed. The Modwright Oppo-105D will feed the 5.1 - of which the R/L/Sub will go though the P5 to the amp, the SR/SL/C will go directly to the amp allowing the oppo to do the whole thing for movies - and 5.1 SACD material. The analog Stereo out of the Oppo with the Modwright Tube analog section will go to the P5 R/L input #1, the FM Tuner (yeah I still have one of those) will go to R/L Input #2

The sub out will go to the Velodyne HGS15BG and the R/L out will go to the amp and then to the Sonus faber Concerto's - the remaining channels of the amp (fed directly from the Oppo) will to to the Sonus faber center and surrounds.

Here are the questions:
Should Vpi Super Scoutmaster with the Shelter 501 go to the MC phono In - and at which setting?
Or should it go to my Linn Linto Phono Preamp and then to R/L Input #3?

Just how good is the Phono pre-amp in the P5?

Rick1958's picture

I am maybe (but maybe not) confused about what was used in the evaluation. Seems like Art didn't like the MC input with either load setting, but apparently the carts he used were (MM) mono and (low output MC) stereo. So were all the stereo LPs used with the LOMC thru an external stepup transformer into the MM input? Seems like it.

I assume his comments are referenced to the same MC cart thru the same transformer(s) into the (MM) input on his Shindo preamp?

Apparently NO stereo LPs were evaluated with a stereo MM cart of normal output into the MM input. I also didn't see any comments about the sound when used with the mono (apparently normal output) cart into I assume the stereo MM input.

Similar comment for the line level inputs. Seems like the sources were digital sources thru external DACs into the line level inputs, compared to the same sources into only the USB digital inputs (and not either of the 'higher res' capable digital inputs). So the DAC (at least with USB input) seems to be a little better than the Proton but not nearly as good as the Halide ...

I'd certainly be interested in what a (possibly higher res) digital source sounds like into the other digital inputs, compared to other external DACs ...

Maybe a follow up? I'll probably buy one anyway, but it'd be good to read about what folks with lots of other listening experience think about it. Which to me is the main point of reading Stereophile. I could listen to other components in showrooms, etc., but the real test is long term listening to a variety of components in one's own listening environment ... that is why your magazine continues to be important to us 'regular folk'.

Rick1958's picture

I am 'afraid' that the MM input won't have enough gain for this HOMC cart ... and since the MC inputs are crappy, seems like I'd need another 10dB or so of gain ... BUT aren't all SUTs low impedance input? Not suitable for the Denon cart. Arrrgggghhh.

Probably only way to know is to try. Know of any ~10dB gain SUTs or whatever with 47k inputs?

X