First Watt J2 power amplifier Specifications

Sidebar 1: Specifications

Description: Two-channel power amplifier with JFET output stage and balanced and single-ended inputs. Power output: 25Wpc into 8 ohms (14dBW), 13Wpc into 4 ohms (8dBW). Frequency response: 4Hz–100kHz, –1dB. Input impedance: 100k ohms. Input sensitivity: 280mV=1W, 1.4V=rated power. Distortion: 0.025% at 1W into 8 ohms at 1kHz. Balanced input CMRR: –60dB at 1kHz. Noise: 100µV unweighted, 20Hz–20kHz. Voltage gain: 20dB. Output Impedance: 0.4 ohms. Damping factor: 20. Power consumption: 200W.
Dimensions: 17" (430mm) W by 5.5" (140mm) H by 15" (380mm) D. Weight 25 lbs (11.4kg).
Price: $4000. Approximate number of dealers: 15. Warranty: 3 years, parts & labor.
Manufacturer: Pass Laboratories, 13395 New Airport Road, Suite G, Auburn, CA 95602. Tel: (530) 878-5350. Web:

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)?