April 2009 Reviewed by Jeff Van Dyne	Parasound A 52 Multichannel Amplifier

Description Model: A 52 Price: $2250 USD Dimensions: 17.25"W x 5.875"H x 19.75"D Weight: 50 pounds Warranty: Five years parts and labor Features 125Wpc into 8 ohms, 225Wpc into 4 ohms (manufacturer rated) Circuitry designed by John Curl THX Ultra2 certified High-bias class-A/AB operation Balanced inputs with discrete circuits and XLR connectors Direct-coupled, with no capacitors or inductors in signal path

Features (cont'd) Complementary MOSFET driver stage and JFET input stage 20 beta-matched 15A, 60MHz bipolar output transistors 1.4kVA encapsulated toroidal power transformer with independent secondary windings for each channel 100,000µF power-supply filter capacitance DC servo and relay protection circuits AC present, channel status, high-temperature indicators Heavy-duty 24k gold-plated five-way speaker terminals Gold-plated RCA input jacks; ground lift switch Auto turn-on by 12V trigger or audio signal, 12V trigger out 3u chassis, carry handles, rack-mount adapter included

I’ve always admired Parasound products. I was introduced to the brand years ago, at a small, independent audio dealer in the Peoria area -- one of those places that makes the case for bricks-and-mortar stores by its policy of "service comes first." To this day, when I see Parasound products in an audio store, my expectations of that retailer rise high -- and, for the most part, those expectations have been met over the years. My impression of Parasound is of a company that chooses its partners very carefully, and I’ve always felt that that philosophy extends to their product design, component selection, and assembly as well.

Parasound has produced a number of amps over the years that, to my ears and wallet, set high standards of performance at their prices. Remember the HCA-1500? Or how about the HCA-2205? It doesn’t hurt that Parasound hires industry legend John Curl to design many of its amps. That’s about as close to a sure thing as you get in this business. And because Curl designed Parasound’s A 52 five-channel power amplifier ($2250), my expectations for it were very high.

The A 52

As I unpacked the A 52, my first reaction was that here was an amplifier that isn’t just attractive, it’s pretty. The look is cool and classy: The company’s name is subtly stamped into the top plate, and the simply contoured front panel is evidently machined and polished with great care. There’s a power switch, and a status LED for each of the five channels; these glow a deep blue when the amp is powered up.

On the rear panel are two handles that come in handy when trying to shift this 50-pound amp around. Each of the five sets of binding posts is accompanied by a balanced and an unbalanced input. Oddly, the power-trigger input and output jacks are 2.5mm instead of the more common 3.5mm, which forced me to dig deep into my cable box for an adapter. Before I found the adapter, I tried triggering the amp by the input signal. This involves setting a switch on the rear panel and adjusting a small dial to set the voltage at which the A 52 amp turns on and off. I eventually got it to work reliably, but it took a fair amount of fiddling and experimentation. If you have the option, use the trigger.

The A 52 is based on a fairly large, 1.4kVA toroidal power transformer enclosed in an epoxy-filled steel shell to further shield the rest of the amp from stray noise. To list just a few goodies from Parasound’s design notes: Once the amp has reached its normal operating temperature, a relay kicks in to entirely bypass the soft-start circuit. The transistors in the circuit path comprise a hybrid combination chosen for the properties desired for each stage: JFETs for the input stage, to minimize the impact of the impedance of source components; MOSFETs for the driver stage, for their low odd-order harmonic distortion; and bipolars to do the heavy lifting in the output stage, where their ability to withstand high-power operation is needed for long-term reliability. As for parts quality, the A 52 includes such things as 1% metal-film resistors, poly and mica capacitors, and glass-epoxy circuit boards. There are more details than I have room to elaborate on here, but you get the idea: great build and parts quality.

Listening

I’ve begun to wonder if it’s possible for Pixar to screw up. While there are a few computer-animated features in the Pixar catalog that I like better, WALL-E (2008) is still an incredibly solid effort from the studio, and from a technical standpoint, their work has never been better. In fact, the picture and sound of WALL-E are so technically superior to that of their first feature that Toy Story (1995) now looks downright old-fashioned in comparison. But while Pixar’s animators paid much attention to the visual environments depicted in WALL-E, all of those efforts would have been for naught had there not been an equally rich and believable sonic backdrop. This depends on being able to re-create all of WALL-E’s subtle and not-so-subtle sonic cues with great accuracy. The A 52 reproduced perfectly placed subtle effects and ambient noise with greater precision than I’ve ever heard in this price class.

Another of 2008’s best films was The Dark Knight, due in no small part to the strength of the late Heath Ledger’s performance as The Joker. We’ll never look at the comic-book genre quite the same way again. This darkest of the Batman movies is by far the best, in my book, and is helped immensely by some of the best sound effects Hollywood has produced. The result is impressive, to say the least. Once again, the Parasound stepped up to the plate and hit one out of the park, with pitch-perfect sonics, pinpoint placement of sound effects, and a huge ambient soundfield.

I hate replacing films on DVD with their Blu-ray editions, but when the BD of Band of Brothers came along, I just had to see and hear it in high definition. It was worth it. The picture is better than I remember it on HBO-HD, and the sound is phenomenal. The film grain and semi-sepia tone of the video are still there, but the picture is sharper than ever. The sound, while good on DVD, is elevated to a new level on Blu-ray: more detailed, and with greater dynamic range. The bullets apparently whizzing past my head made me want to duck. The resolution and pinpoint imaging of the surround effects was ever so slightly tighter with the A 52 in the system than without it.

But if movies sounded impressive through the A 52, music-only recordings were revelations. I cued up Handel’s Water Music, with Yehudi Menuhin conducting the Bath Festival Orchestra, from the superb Menuhin boxed set (8 CDs, EMI 75517). These recordings, mostly from the 1960s, have held up well, and their digital remasterings appear to have been done with great care. The Parasound A 52 imparted a warm sound, and smoothed out some of the shrillness of the violins in this recording, without in any way diminishing the high-frequency detail. Overall, the sound was pleasant while remaining incredibly cohesive and articulate.

At the other end of the musical spectrum is Zipless: Songs from the Works of Erica Jong, in which not-safe-for-work writings by the poet and novelist are set to electronica/pop/dance arrangements by singer Vanessa Daou and her keyboardist husband, Peter Daou (CD, MCA MCAD-111278). Zipless is uncommonly well recorded for this sort of music, with lots of transparency and air in and around Daou’s voice that the Parasound A 52 showcased particularly well. The imaging was pinpoint, and the soundstage had good depth and width, extending well beyond the boundaries of the speakers.

Comparison

For a couple of years now I’ve been the proud owner of an Anthem PVA 7 seven-channel amplifier -- a great amp for the money ($1500), and I’m still very pleased with it. Before my months with the Parasound A 52, I’d thought the Anthem PVA 7 was about as good as a multichannel amp got for a price not measured in megabucks. It’s $750 cheaper than the A 52 and has two more channels, so the comparison isn’t perfectly fair, but the PVA 7 has always been considered an overachiever, and I’ve found it does a fine job in its own right.

But while the two models are more similar than different, the Parasound took everything to the next level, as a direct comparison revealed. Both were very competent, but what made the A 52 a better amp were its clarity, and its freedom from grain and harshness in the upper registers (perhaps a result of those low-harmonic-distortion MOSFETs?). Nor were the differences nearly as subtle as I’d expected. Through the Parasound, music-only recordings of artists such as Ani DiFranco, which have lots of high-frequency energy, sounded very plainly smoother, and were less fatiguing over long listening sessions. The music retained every bit of the high-frequency detail and transparency reproduced by the Anthem PVA 7, but with almost no harshness or glare. This was no small feat.

The $750 price difference is considerable, especially when you take into account the Anthem’s two additional channels. However, for those who have the cash to spare, the Parasound provided a significant improvement in sound quality.

Conclusion

The Parasound A 52 is one of the finest multichannel power amplifiers I’ve used in my system, with sound qualities on a par with those of more expensive amplifiers. It had me asking myself, Why spend more? This is one amplifier I can recommend with no reservation whatsoever.

Manufacturer contact information:

Parasound Products, Inc.
2250 McKinnon Avenue
San Francisco, CA 94124
Phone: (415) 397-7100
Fax: (415) 397-0144

Website: www.parasound.com

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