Sunday, December 28, 2014

Our Sixteenth Meeting

Ok, fellow audiophiles in the Las Vegas area and everywhere really (this is the world wide web after all,) the first official audio club ever in Sin City, has now completed its sixteenth meeting.

We had our sixteenth meeting on 12-13-14.

At this particular meeting, we had the great opportunity to evaluate the excellent First Watt J2 amplifier designed by the legendary Nelson Pass. This is a single-ended 25Wpc into 8 Ohms running in pure Class A. The retail price is $4000. Click on the link above for more info.

We had a great time evaluating this amp. It was a fun listening session augmented by New York style pizza and soft drinks. Everything from classical to jazz to classic rock was played, and no one left disappointed. Once again, as par for the course here at the LVAC, it was good times indeed.

Without further ado, here are the panel's findings of this amp. Remember, these are only subjective opinions, and as they say, your mileage may vary.


LVAC President and Founder, Dave: The amp is very clean and pure in the mids and highs. High and mid frequency instruments such as cymbals, voices, and acoustic guitars are spot on. Imo, it would be better served as a HF/MR amp in a bi-amped configuration rather than run it full range. At high or higher volumes, the amp tends to clip and tends to run out of gas. The dynamics and bass are a bit restricted on the JBL S4700 speakers. This is not really the amp for headbangers and 1812 Overture freaks. The JBL S4700 speakers are 94db efficient with a 6 Ohm rating. You might think that's enough efficiency, but it seems they actually need more power to wake them up, especially the woofers. The higher wattage (and current) Class A and A/B amps from Pass Labs (like the X350.8) would be a better choice for the S4700s. Now with something like a Klipsch Cornwall or Klipschorn, the J2 would be all you need really. Those are even more efficient and have a higher Ohm rating than the JBLs I use. Overall, an excellent amp that is transparent and has a very organic feel. At $4000 retail, it is a pretty good value as well relative to high end pricing.


LVAC member Les: This is an excellent amplifier when used in the context for which I believe it was intended. At 25 watts into 8 ohms, it was clearly not designed to be over-driven into clipping 25% of the time or more by listening too loud. Played at more reasonable volume levels, I felt that it sounded extremely clean and pleasant.

I appreciated the opportunity to listen to a Class A FET amplifier for the first time. It seemed to exhibit the characteristic smooth clipping of a tube amp.


LVAC member Mike: The J2 is a quite nice sounding amp within its limits.  I really enjoyed the naturalness of the vocals as well at the articulate high end.  The live tracks we played had that "atmosphere" you don't often hear.  The bass is solid and not at all bloated.  The amp kept up with all we could play though it at reasonable sound levels.  If pushed to hard, it would pay the price, however.  I believe the J2 is on par with many high-end SET amps that I have heard.  You also don't have to worry about the added expense of tubes.  I'm sure the target audience with straightforward, high-efficiency speakers will be quite happy with the J2.  It can rock with satisfactory volume for most of us.  I enjoyed the listening session.  Thanks for the demo!


LVAC member Jonathan: Recently, I had the opportunity to participate in a listening session which was highlighted by the use of First Pass’ J2 power amplifier.  This amp was designed by Nelson Pass, best known as the inspiration behind Pass Labs and a renowned engineer in the field of audio signal amplification.

The J2 is a two-channel 25 watt Class A amplifier which uses silicon carbide-based power J-FETs manufactured by SemiSouth Laboratories; unfortunately, that company shut down in late 2012, and those J-FETs are no longer being made.  The amplifier’s MSRP (manufacturer’s suggested retail price) is $4,000 (USD).

Since I  was unfamiliar with the capabilities of the other components used in the system (JBL S4700 speakers, Bryston BP6P preamp, Onkyo DX-7555 CD player, FM Acoustics interconnects and Bryston SC4 speaker cables), I focused my evaluation effort on discerning – to the extent to which I am capable – the impact of the J2’s power amplification on the sound being reproduced.

Not surprisingly, when music was played at an apartment-friendly volume, what I heard was excellent low-level detail that was both accurate and spatial.  Absent were the “clinicality” of some solid-state amplifiers and the pleasing warmth (aka distortion) of their tube counterparts; the J2 is most definitely neutral in terms of a sonic imprint.  However, when the volume was raised and the amplifier was called upon to drive high level transients, the result was far less pleasing.  Clipping occurred frequently.

My conclusion is that the First Pass J2 amplifier should be seriously considered by anyone whose listening preference is overwhelming oriented towards chamber music and who seeks to avoid raising the volume of his music to a level that might impose upon his neighbors due to thin apartment walls.  Everyone else will likely find more versatile, and equally fine sonically, power amplifiers readily available for a similar price. 


LVAC member Terry: I thought it sounded fine, particularly on "simple" passages. I thought when music got more complex or loud it did not hold up well.


The LVAC would like to give special thanks to Desmond Harrington, President of Pass Labs for making all of this happen.

Photos are below. Photos by LVAC member Barry.

the system

The First Watt J2 in all its glory

The listening panel

2 comments:

  1. This is great information!! I really want to attend this meeting but due to some business projects, I will not able to come there. I really want to know that which meeting rooms you have booked. Please let me know.

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    1. Just keep checking this blog for all of the latest info! Thanks!

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