First Watt J2 power amplifier Page 2

I played the Klemperer St. Matthew Passion relatively loudly: zero stridency, opacity, or glare. Tone was right on. The upper bass and lower midrange were uncommonly dense and rich. Massed choral voices and strings have rarely sounded more relaxed, well differentiated, or natural. Trumpets and violins were special joys.

I played "I Wish I Was a Mole in the Ground," by lawyer, singer, and folklorist Bascom Lamar Lunsford, from Volume Three: Songs (Blue Singing) of Harry Smith's Anthology of American Folk Music (CD, Folkways FP 253), and became so happy. This is pure American banjo-picking blues, and I am wired to accept and understand it. The First Watt and Falcons played the livin' bejesus out of this jaunty lament. Natural tones and rollicking rhythms drove me straight through to Appalachia.

With KEF's LS50s
The KEF LS50 is a respected, Class A, reference-quality minimonitor—but it sounded strangely wrong with the First Watt J2. The Trashmen's iconic "Surfin' Bird" (7" 45rpm, Garrett GA-4002) played with strength and force, but its tonal balance was skewed: The lower octaves were eviscerated. My favorite Professor Longhair song, "Cry to Me," from his Live on the Queen Mary (CD, Harvest SW-11790), sounded almost rinky-dink—like a car radio. The Professor's left hand sounded as if it was playing a toy piano, as whatever keyboard he played with his right hand went in and out of focus.

When John Atkinson measured the KEF, he noted that "the LS50's impedance . . . drops to 4 ohms at 200Hz and to 5.4 ohms at the top of the audioband. The electrical phase angle is generally mild, but the combination of 5.3 ohms and –41° at 135Hz, a frequency where music often has high energy, will make the speaker work at its best with a good, 4 ohm–rated amplifier." The J2 is clearly not that amplifier.


Which reminds me how many audiophiles fail to realize that sensitivity ratings are rarely a wise guide when matching power amps to loudspeakers. For example, my Falcon LS3/5a speakers are even less sensitive than the LS50s (82 vs 85dB), but are generally happy with low-power amplifiers. (Rated for 25W, the Falcons often play well with 5–10Wpc single-ended amps.)

With Technics' Premium Class SB-C700s
To my complete surprise, the First Watt J2 sounded significantly better with the 4-ohm rated Technics SB-C700s than it did with the Dynaudio Excite X14s or KEF LS50s—but not better enough to recommend.

Comparison: Line Magnetic LM-518IA
Because my reference integrated amplifier, Line Magnetic's LM-518IA ($4450), has a preamp input, nowadays I use it mostly as a stereo power amp. It's most likely a gain or buffering issue, but the LM-518 sounds more transparent and dynamic when driven by a separate active preamp. (I suspect that the LM-518IA actually is a power amplifier with a volume pot and selector switch grafted to its input.) When I drove it with the Pass Labs HPA-1 line stage/headphone amp, it sounded cleaner and more grainless than it did as an integrated.

I compared the Line Magnetic and First Watt amps using only the DeVore Orangutan O/93 speakers, which seemed happy dancing with either 20-something-watt design.

The St. Matthew Passion ends with a sorrowful chorus, "Wir setzen uns mit Tränen nieder," sung mostly by full choir. When the boys' choir enters, the sound was luminous and glorious in the extreme with the Line Magnetic, but more lightly rendered than through the First Watt—some of the energy in the 60–300Hz range had gone missing. Bass weight and volume were noticeably reduced.

With the Line Magnetic, the top octaves felt fresher and more vibrant, but surprisingly, the LM-518's soundstage was smaller than the J2's.

Of these similarly priced and equally powerful amplifiers, the LM-518IA was more vivid in its portrayal of women's voices, stringed instruments, and cavernous spaces, while male voices, electric guitars, and pianos sounded more tangibly real through the J2. Driving the DeVore O/93s, the First Watt delivered a better-controlled, more spirited nine-octave energy balance than did the Line Magnetic.

On a night full of amp comparisons and 7" 45s—a night that included my beloved Little Sparrow, Édith Piaf, singing Georges Moustaki's brilliant song "Milord" (Pathé Marconi/Columbia ESRF 1245)—I noticed how the Line Magnetic LM-518IA presented me with a magnificent re-creation of Piaf's mouth, diminutive stature, and voice. I became the microphone. The First Watt J2 let the piano sound more as it should, and let the song's momentum build and release in a most captivating way. Both amplifiers showed me the soul of ombre de la rue (shadow of the street). Both amplifiers made me glad I collect 45s.

A reader once asked, "Herb, why are all your reviews so effusive and positive? Why can't you be more dire and critical?" My answer: I do not review things that just mysteriously appear on my doorstep. I work hard to seek out high-value components of all types. Behind the scenes I'm always digging about, listening, asking questions, and taking suggestions from my peeps. My goal is to serve my readers by discovering products that are mostly affordable and worthy of glowing effusion. Why would I waste your time, my time, and Stereophile's pages on anything not wonderful and worthy of our collective consideration? I make some effort to report on happening new products, but I'm happiest when I discover a not-so-new but critically underestimated or overlooked product.

The First Watt J2 by Nelson Pass has been written about here and there, but it seems that everyone who's written about it has been in a giant a hurry to say, "It's a solid-state amp that sounds like a tube amp." But when I experienced the J2 in my own system, I felt that this generalization was both inaccurate and inadequate. With loudspeakers of benignly high impedance, the First Watt J2 tracked complex music signals in ways I have rarely experienced.

The J2's extraordinary ability to keep close and intimate with complex music, such as early Nina Simone and Klemperer's Bach, allowed my humble reference system to display the music's fundamental chi in a singularly engaging way. Very few power amps can do this.

I used to sell $90,000, 25Wpc tube amps for a living. Currently, I use an extraordinary $4450, 22Wpc tube amp as my reference, so believe me when I say that the beauty of the First Watt J2 has nothing to do with the tubes-vs-solid-state debate. The J2 rises high above that dispute between cults. Most likely, the First Watt J2 preserves music's vital chi because it's a simple, high-bias, class-A, single-ended, low-feedback design, created by Nelson Pass—one that has no need to impress the mainstream masses or drive 4 ohm speakers.

Nelson Pass is a chi master because, like me, he's a member of all audio tribes. "There is no such thing as a perfect amplifier," he believes. "All audiophiles and their associated equipment have specific needs, but in each case there is such a thing as a best amplifier—the one that makes you happy." The First Watt J2 is, in my view, a best amplifier: Every day, it made me and my favorite loudspeakers extremely happy. Highly recommended.

Pass Laboratories
13395 New Airport Road, Suite G
Auburn, CA 95602
(530) 878-5350

noelberkowitz's picture

I have been listening to a J2 with Audio Note AN-J HE speakers for a couple of years now and my findings are very similar to yours. the amp creates a very strong emotional connection to the music.

Joe Roberts's picture


I should point out to readers that you were the first writer to popularize the later-to-become-iconic term "first watt" about 25 years ago.

Perhaps you are too humble to mention this...or, more likely, you totally forgot!

Ktracho's picture

Anyone know how this amp compares to First Watt F7 amp? In general, I'm not sure how one would go about picking between the different models, other than to guess how well it matches the impedance of one's speakers, but if the speakers are sufficiently high in impedance and sensitivity, then what would you gain for the extra $1000 that the J2 costs over the F7?

FritzSpeakers's picture

Hi Ktracho- For more info regarding the difference between the J2 & F7 (and the Pass SIT-1 mono blocks), check out the write up by John Richardson on all three amps with 3 different loudspeakers including Zu's Druid Mk. V, ATC's SCM 19 version 2 and my own Carbon 7SE's.

Allen Fant's picture

Nicely done! HR.
this amp is on my must-demo list. I would have subtracted Charlie Hansen (a flake) and added Dan D'Agnostino to your list as above.

Otherwise a very good article. Happy Listening!

Les's picture

My guess is you have never listened to any Ayre products (nor even D'Agostino's for that matter). If you have, would you describe the sound as "flakey" too? Actually, logic dictates that you must, since you want him off the "Chi Masters" list. Can I safely assume that you dislike the sound of Ayre amps? Or do all designers have to align with your personal beliefs, despite the fact that they produce amazing products...

Allen Fant's picture

Sure, I have auditioned both D'Agostino and Ayre amps. Nothing inherently wrong w/ the products per se. I have seen many of CH 's comments in the various forums and he has always presented himself as a flake.

Those of us who have been in the hobby for 20+ years understand that it is "flake" laden.

rockdc's picture

it's listed as 101 dB on the website. Are yours really 96 dB?

John Atkinson's picture
rockdc wrote:
it's listed as 101 dB on the website. Are yours really 96 dB?

The specified sensitivity is, shall we say, "optimistic." My estimate of our review sample's voltage sensitivity was 91.5dB/2.83V/m.

John Atkinson
Editor, Stereophile

rockdc's picture

I'm surprised. In the measurements for the Soul speaker review, you state "My estimate of the Zu Soul Supreme's voltage sensitivity was 91.5dB/2.83V/m, which is lower than the specified 97dB/W/m but still much higher than average". Zu states 101 dB. Where does the "specified 97db/W/m" number come from? And has Zu had any response to this?

Steve Tag

hifiluver's picture

does this amp have a built in equaliser (Fig.1)?