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First Watt B1 Buffer Preamp and J2 Power JFET Amplifier Review

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Double the amp, double the fun!

However, one can juice the performance of a set of speakers simply by adding a second amplifier. We could consider this recommendation as putting power on your side, even when it is lower power. What do you get when you add a second J2? You get twice the audiophile goodness of using only one J2!

Some things are simply more fun when they are doubled. As a young man, viewing Wrigley’s Doublemint chewing gum advertisements was doubly enjoyable since they featured shapely identical twins. This brings to mind that I once dated identical twins – no, not at the same time! I never could be sure which one I was talking to by their appearance, however I could tell them apart by their sense of humor, so I told a lot of jokes! Though perhaps not as daring as dating identical twins, there is something doubly fun about having a pair of amps sitting up front, a type of “double whammy.” If you recognize that phrase, the odds are you’re getting pretty old. Ask any audiophile; a pair of meters is twice as mesmerizing as only one!

Over the decades with the systems that I have built, I still do not have an absolute answer as to which is better, one more powerful amp or two less powerful ones. It is very tempting to secure two less expensive amps and power each speaker with one. If only it were simple, such that any given design in the form of two 100Wpc amps were identical to a similar 200Wpc amp. They are not, due to each power amp having individualized power supply, capacitors, transformers, circuit board layout and internal wiring. Nelson could likely point out four or five additional, more subtle reasons. Nevertheless, in such cases where a design is simply beefed up while built on the same platform I usually prefer the more powerful amp as it typically has superior cleanness, soundstage extension, bass depth and impact, and the system more coherence overall.

In this particular instance, the J2 amp does not have a “Mono” switch, so when using a pair of them one must provide a double set of outputs from the preamp. It is also absolutely necessary to have a speaker that is bi-wireable. I typically use a pair of Audioquest RCA “splitters” to allow for two sets of interconnects to be used. Both of the interconnects leaving the left output from the preamp run to both of the inputs on the J2 amp dedicated to the Left speaker, and two sets of speaker cables are sent to the two pairs of binding posts of the speaker. Similarly, the doubled interconnects exiting the preamp from the right channel output are sent to both inputs of the J2 amp dedicated to the right channel speaker, and the two set sets of speaker cables sent to the two pair of binding posts. This is how I wired up the Vapor Audio Joule White 3 for this review. (Using a splitter has adverse effects on output impedance.  The only proper way to biamp (without an active crossover) is use a preamp with two discrete outputs.-Copy Ed.) (Or use two B1, one for each channel. -Pub.)

For the setup mentioned just below, utilizing the PureAudioProject speaker, I could not use this setup, as the speaker is single wired, not bi-wireable. I dare not send two channels of amplification to one set of speaker posts, or else I will short the amp! So, in the instance of having a speaker with only one set of speaker posts I simply use one channel of each amp for each speaker. I take the respective single interconnect Left or Right out from the preamp and direct it to only one input of a J2 amp. One channel goes unused. The output from the single channel is sent by the one speaker cable to the single pair of binding posts of the respective speaker. My understanding is that instead of the transformer of the amp servicing two channels, in this configuration it services only one channel per speaker, thus providing better performance than one stereo amp. Though not purposed for it, this setup is a way to turn stereo amps into “Mono” amps. Perhaps Nelson might wish to comment upon this setup in response to the review.

Audio by Van Alstine ABX Comparator

However, when it comes to comparison of amps of different brands my experience is that only direct comparison will tell whether a single, larger stereo amp is better or a pair of smaller amps. Can a pair of 100wpc amps seem superior to a stereo 300wpc amp of a different make? Yes, and a pair of 200wpc amps can sound superior to a 1,000-Watt class D stereo amp. There is so much variance in the sound of amps in systems (see my review of the Audio by Van Alstine ABX Comparator for a qualification of that statement.) that there can be no assurance any given larger stereo amp will sound preferable to a pair of smaller ones of a different make. How many times have I tried such comparisons? I venture to say a dozen times, and the results have been unpredictable.

Thus, I cannot say without qualification that the addition of two J2 amplifiers will ensure superior performance to many higher-power amps. I qualify my statement since I prefer holistically what the J2 amp does to the higher-power Pass Labs amplifiers I have used. What it will do, however, is lend the sense that you are underscoring the sonic characteristics of the J2. Note the descriptions of the amplifier’s sound in this article. If you are drawn to that description you will find a pair of them to give you even more of those attributes.



The next configuration was as streamlined as it gets:

Mac Mini using HQPlayer software, up converting PCM to 32 bit/5.6MHz
Verastarr Nemesis USB Cable
Eastern Electric Minimax DAC Supreme with Verastarr Grand Illusion 2 Power Cord
TEO Liquid Reference Interconnect
First Watt J2 Amplifier x2
TEO Liquid Standard Speaker Cable; bi-wire  (speaker cables parallel double wired)
Pure Audio Project TB15 Speaker


With this system I used the volume control of the HQPlayer software on my iPad controlling the Mac Mini as the main level control. The sound of the same tracks listed above was more detailed and with much more dynamic power, but also decidedly with a “neutral” or even white character, with less warmth than I desired. The system was moving toward the kind of resolution I anticipated could be obtained. However, there was far less ability to contour the presentation; excepting the flexibility of the Minimax DAC Supreme, an owner would be “stuck” with the outcome for good or ill, except for cable changes.

Now that I had tried some alternative setups I had some familiarity with the ends of the spectrum of performance of the First Watt components, and it was time to set up more traditional and hopefully more beautiful sounding systems.


Too many options!

It became apparent quickly that with the addition of the B1 to the selection of components to build systems that the number of permutations of gear and speakers would exceed the limits of this review. Consequently, I selected for discussion a few setups representative of what can be done with the B1.

Keeping the above system intact, I added first the TEO Liquid Pre, then the First Watt B1 Buffer Preamp. After the Liquid Pre was inserted the sense of the physical distance between instruments increased and filled the acoustic canvas better, while warming up the tonal pallet. The J2 amps were less dynamically forceful and lighter on the bass than either the SST Son of Ampzilla II or the Red Dragon S500, but a sense of “lightness,” or perhaps best described as a bit more openness characterized the J2’s performance. The cover of Fleetwood Mac’s “Landslide” by The Backbeats showcased this lightness with gently intertwining vocals that were well delineated, such that my mind could capture the location of each singer. The voices were more fully rounded by the addition of the Liquid Pre to the B1.

One of the more evident differences between these other amps with their higher power and the combination of the B1 and J2 is what I will term “cabinet capitulation.” With higher power the speaker drivers seemed more divorced from the cabinet. As I had swapped out the speakers for the Vapor Audio Joule White 3 and repeated the comparisons I observed that when higher power was used I was drawn more to the sound of the drivers themselves, but when turning to the lower-powered J2 I found myself hearing, and appreciating, the contribution of the cabinets. I was no longer glued to each individual driver’s performance, but they receded enough to gel together, and along with the cabinet brought a comfortable ease to the listening session. It was as though the drivers had capitulated to the presence of the cabinet, and instead of them bursting forth they were settled in, the speaker showing its character in entirety. The trade off was LF presence and dynamic impact in exchange for a warmer, less visceral experience.

This effect was even more pronounced when the B1 was in the system. The more streamlined the rig, and with higher power, the Joule White became a super-monitor with no mercy on the ears when provided less supple recordings. When the B1 and Liquid Pre operated together the Joule White 3 acted more as a relaxed floor standing speaker. No longer was my ear especially drawn to the impact of the Audio Technology bass driver, but my ear could float freely latching onto whatever part of the frequency spectrum I desired. Analogue and tube amp fans would certainly appreciate this shift.

Many audiophiles enjoy “boxy” speakers such as Tannoy, Harbeth, Audio Note, and the like. The Vapor Joule White 3 has a fantastically inert cabinet, quite unlike these others, which hides well when higher power amps are employed. To turn this speaker “softer” the B1 and J2 with an appropriate preamp were the right pieces to make the speaker sound less forward and more reserved. Some listeners will seek that effect, as it softens the edges of transients and lends a sense of the speaker not being driven hard, even at higher levels.


With the Pure Audio Project TB15 Voxativ


Previously, I stated my preference for the J2 over the other Pass Labs amps I have reviewed. The breadth of performance of the Pass Labs line is extreme. Also remarkable is the differential in performance between the standard Tang Band setup of the Pure Audio Project speaker and the upgrade Voxativ version. I only had it a short while before returning it temporarily for a show, but the Voxativ AC-1.6 driver made an immediate and indelible impression upon me. It was as if I was hearing an entirely different design, such were the benefits the Voxativ driver conferred. From a man who has been sold out to mega floor standing speakers for decades, this may sound incredible, but using the Voxativ AC-1.6 began to show me two things; why audiophiles might eschew multi-way speakers, and how a company might charge many thousands of dollars for a single full-range driver. As I intimated in my pre-review comments at the Pure Audio Project website, I was not prepared to be blindsided by the beauty which these drivers delivered.

The pairing of the J2 and TB-15 Voxativ was a breath of high-end fresh air. Here was a sound with an unassailable center imaging so precise and fleshed out that a heretical thought entered my mind, that I could see why someone might eschew low frequency response for it. Mind you, I would not trade off LF, but then again I am loath to trade any sonic improvement away willingly!  The tender J2’s low-end blended oh-so-sweetly and distinctly with the twin 15” open baffle OB-A15 Neo bass drivers, so thankfully I did not have to make that agonizing choice.

I’m not a mushy music guy who weeps every time I hear a pretty voice. But, listening to William’s “I’m Just A Country Boy,” once again turned my mood melancholy. This song about a low income guy who’s so thoroughly unworthy of the girl that he figures he can’t even try was so lugubrious that I thought to myself, “Poor sap!” Though the TB-15 Voxativ only stands about 4’ tall, Joan Baez’s “Diamonds and Rust” seemed of epic proportions; I was transfixed by the purity and intimacy of her voice. Yes, the B1 and J2 with the right higher efficiency speaker, an extremely coherent one, brought the pain – the artist’s pain, that is!


Wrapping up

The First Watt B1 Buffer Preamp I found to be more difficult to drop into a system and be content. I had to work with it more than the J2 Jfet amplifier. Once I knew the limits of the J2’s character I built systems with highly satisfying sound. The J2 especially is a jewel with many brilliant facets to behold. While the B1 Buffer Preamp can massage a system to bring deeper hues and a somewhat more extended sense of scale, the J2 is to me the premier product of the two. It mates capably with multi-way speakers, but a premium full-range, single-driver speaker seems an option to be considered well. That combination was as rich and ornamented as could be expected of an audiophile system. Especially for those yearning for an amp to pair with their high efficiency speakers, but tired of the troubles with tubes, the J2 should be in their sights.


Copy editor: Laurence A. Borden

One Response to First Watt B1 Buffer Preamp and J2 Power JFET Amplifier Review

  1. Abhijit says:

    Just one question, do you feel having a bi-amped J2 has a clear advantage over single J2 ?

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