I love Extreme's album III Sides to Every Story, because there's such a diverse m�lange of sounds from one track to another. There were a couple of tracks I wanted to test out especially. First was "Tragic Comic," an acoustic track featuring the band's patented a cappella harmony vocals against a backdrop of acoustic bass and guitars. Unlike many big hair bands of the '80s and '90s, where one lead singer belts out all the vocals, all of Extreme's band members can sing well. Here, the midrange vocals sounded sublime. Texture was sweet and natural. Nuno Bettencourt's Washburn guitar sounded rich and woody like it's supposed to. The bass was musical and resolute. Though never sounding flabby, the bass delivered to the 12-inch woofers of my Salk speakers was not quite as tightly controlled as my more powerful Crown I-Tech 8000 amplifier.
I tested the amplifier with some benchmark material to check for distortion, and true to its specs, there was nothing glaring across the bandwidth spectrum. I've found one of the best ways to doublecheck with music is with an electric guitar heavy track. Rock guitarists often use effects pedals and overdrive to deliberately add distortion to deliver a specific sound they like. It's unnatural, but it's a specific kind of "unnatural" that they're looking for. Audio components that have significant inherent distortion create noticeable problems when reproducing this sound in music, especially in the upper registers.
With the track, "Rest in Peace", there was no shortage of material to test with. Here Bettencourt's guitars were crisp and with none of the harshness you get from distorted audio components. While the Parasound JC 5 got everything right tonally, I did notice that it was a bit lacking in energy, as power chords and heavy drum solos appeared a bit reserved or polite. �
Amy Winehouse's "Back to Black" proved a pleasure to listen to as well. Winehouse's voice came with all the raspy, squawky texture that made her so appealing to fans. Instrumentals sounded open and airy. The JC 5 handled all the starts and stops of her punctuation adeptly. Sonically, there wasn't much else I could ask for here.
Star Wars: The Last Jedi was a pleasure to watch with the Parasound in my rig. The dialogue was crisp, clear, and engaging. All the action brought me back to when I was sitting in a Dolby Cinema theater watching it for the first time. The lightsaber action was equally enthralling. There were only a few moments where I felt like there could be a little more. One such was in the opening credits scene, where I felt John Williams' orchestral score didn't have quite the full bloom and scale it should. Another was toward the end of the film when Luke Skywalker was being shot at by an entire First Order battalion. Here, it was just shy of the earth-shaking experience expected.�
My Salk Signature Soundscape 10 speakers have a nominal impedance of four ohms, which means they are more current-hungry than typical speakers. With a sensitivity rating of 84db and 12-inch woofers for the bass, these are probably the most difficult speakers to drive that I've owned. While I didn't expect to have any issues with headroom here, given that the JC 5 is rated at 600 watts into four ohms, I decided to test again with two different speaker sets.
One was a pair of B&W CM6 S2 speakers supported by an SVS PC-13 Ultra subwoofer, where the SVS subwoofer provided its own power. Another was a pair of Paradigm Persona 5F speakers, where bass is not powered, but each speaker is 93db sensitive. Both would present much easier loads to drive. Retesting all the problem areas found previously, I found the Parasound more than capable of driving both these speaker combinations with ease. Bass reproduction was flawless and sense of scale and dynamics left nothing on the table.
One might ask, why would it be possible for any load to be difficult for a 400-watt amplifier to drive? One answer can be found when we compare closely the differences between the Parasound JC 5, and, say, a pair of the JC 1s, which are also rated at 400 watts per channel. The power supply on the JC 5 has a peak current capacity of 90 amperes per channel, while each JC 1 amplifier has a peak current capacity of 135 amperes. A speaker like the Salk Soundscapes draws more current, and taxes the power supply on the amplifier more heavily. When powering speaker with four-ohm resistance, the JC 1 happily doubles down and delivers 800 watts of power--double the 400 watts it would deliver if the speaker had an eight-ohm impedance rating. However, the JC 5 only puts out 600 watts. Simply put, while the JC 1 has more juice to give if a speaker can take it, the JC 5 only has so much juice to give. Obviously, all of this is just technical, because every amplifier has its limitations. And conversely, there aren't a lot of speaker loads out there where an amplifier like the Parasound JC 5 would be found deficient in face of. But I do believe I have tested its physical limits from a practical standpoint.
While I tested with music and heard no audible distortion, I went back and played through some sample files I use to check for intermodulation distortion (IMD). As high-resolution music formats are becoming more important for our readers, it is important to note that testing for IMD in audio components becomes proportionally important as well. High-resolution music, along with the high sampling rates, are bringing ultrasonic content. You can't hear this, of course, because it is beyond the audible frequency range. But if your amp isn't linear up to 48 or 96kHz, the most common high-res formats can introduce distortion downstream in the audible range.
I tested using material at both the 24 bit/192kHz and 24 bit/96kHz sampling rates. At normal listening distances, I heard absolutely nothing, no distortion. While many high-end audio amplifiers are beginning to keep ultrasonic frequency induced IMD in mind for the design process, it is by no means an industry standard. For Parasound to have such stringent design criteria on the JC5 is impressive indeed.
This amp is not small, so if you're looking for a space saving, lightweight item that you can toss into your backpack and lug around, then you'd better think again. That is unless you intend to make this part of your Crossfit workout. But I would say, outside of Class D amplifiers, most audio amplifiers that can output 400 watts per channel are not going to be either small or light, so this would be more of an understanding than a knock on the JC 5. (Though the Micromega M-150 that Dennis Burger recently reviewed was only 22 pounds.) So, what about the sound? Well, it is after all a John Curl designed amplifier, and true to its designer's reputation, so there isn't a whole lot to complain about sonically. The only one downside that keeps the Parasound JC 5 from competing with the upper echelons of stereo amplifiers is its ability to drive the most difficult loads.
Competition and Comparison
At $6,000 for a stereo amplifier, there is no shortage of competitors. For $,1000 less, you can get the ATI AT-6002 amplifier. Jerry Del Colliano raves that it is "the world's leading contender for a bang-for-your-buck amplifier." The JC 5 sounds sweeter, especially at lower volumes, Sonically, I think the Parasound has just a tad more refinement as well. The ATI is only rated at 300 Watts on paper, and while I've never tested it in home with my Salks in particular, don't get so hung up on the nominal specs. I've heard the AT-6002 being demoed handling very impressive loads with no issues. So, if you want more power but don't want to pay more, the ATI amp should be on your audition list to compare.
One of the JC 5's features is the ability bridge both channels to serve as a monoblock amplifier. It's worth noting, though, that two JC 1s cost $3,000 less than two JC 5s. And as Parasound notes in the manual, "Bridged 4-ohm operation is not recommended," so not all speaker loads will work with this setting. In addition, the JC 1 stays in Class A operation for the first 25 watts instead of the first 12, for those who just adore that unbeatable Class A purity. If you're going to use the Parasound JC 5 in bridged mono setting most of the time, just get a pair of the JC 1s instead.
Anthem recently debuted their new flagship STR line of two-channel products. At $5,999, the Anthem STR amplifier carries the same retail price tag as the Parasound JC 5. The technical specs, are quite similar on both amps. Though the Anthem, still heavy, is only 60 pounds. I'm still in the early stages of listening to this one (review coming), but this is definitely another one you would want to audition in this price range. And it has no problems driving any speaker I have on hand.
The JC 5 has enough power to drive almost any pair of speakers to your satisfaction. But while the JC 5 was able to drive my speakers adequately, I happen to own a pair of speakers that could use just a little more than what the JC 5 could give. In the event that you have or are thinking about a pair of speakers that may present an excessively demanding load to drive, you may need to evaluate whether that applies to you. I do need to warn you, though, dear reader, that quality equal to the Parasound JC 5 with even more power will likely cost more. Sometimes significantly more.
With that said, like its big brother, the original JC 1, the Parasound JC 5 is a stunning amplifier. I heard next to no distortion whatever the material I flung at it. It plays clean and neutral, a living embodiment of how close we've come to the ideal of straight wire with gain. That is, it maintains its musicality and never gives off that sterile sound you hear from many amps trying to attain surgical precision while sucking the life out of your music. The JC 5 just plays whatever you want the way it was meant to be played. For all but the most stringent of power requirements, this amp will be everything you're looking for. And hey, who says you have to buy the amp to match your speakers? You may decide to just buy the Parasound JC 5 and find a pair of speakers that will fit. Should you decide to go that route, we at HomeTheaterReview.com have done a lot of the legwork for you.