MSRP: $1,000


Jaton made a powerful splash at the Rocky Mountain Audio Fest last year with the AP2140A Operetta amplifier. I spent a fair amount of time soaking in the Green Mountain Audio Calyspo speakers powered by a beautiful two channel Jaton AP410A amplifier. The LM3886 chip amplifier serves as the backbone. A chip amp? An even crazier notion is that the amplifiers are in separately loadable amplifier modules. The unit comes loaded with two modules but one can add up to three more, each a modest 70wpc into 8 ohms. Adding an amplifier module is like installing a porch light bulb. Pop the top and insert. Our review sample was two channel in true Stereomojo fashion.

The power supply is a nice torroid, powerful enough to supply up to five channels at 70 watts each into 8 ohms. This translates into a little extra dynamic headroom and a sense of competent power for those who purchase the AP410A amplifier for two channel music. More about that later. Well respected parts are found throughout; including Vishay resistors, Nichicon and Wima capacitors. The high end parts list doesn't follow the relatively reasonable price. A fan in the chassis is an interesting quirk here. Combined with the pictures of the open unit looking a little bit like an open PC and reservations set in. Did it really sound that great? I would know soon enough.


The Operetta amplifier arrived in a hefty box. Inside it was pre-packed into a soft protective carrying case. A nice touch. I used it when bringing the amplifier out on the road for an audio get together in an effort to gather opinions from others. The 47 pound amplifier conjured grunts and groans as I slid it in place of my reference Forte Model 5 amplifier. The initial preamp used was not my Jaton RC7000P but the preamp section of the Bryston B100 SST. This is essentially a Bryston BP16 class A preamplifier that easily outclasses the Jaton preamp costing many times less. The interconnects were simply blue jeans LC1 cables and the speaker wire was Kimber 4TC. The source was a Pioneer Elite DV47A feeding a DAC AM modified by Pacific Valve.



The amplifier was plugged directly into a PS Audio hospital grade outlet on a dedicated line au-naturale. I reused the existing Volex 17604 power cord, never trying the stock power cord. Several sets of speakers were used but they were mostly a set of open baffle speakers using GR-Research drivers and B&G planar ribbon tweeters. The Jaton AP2140A Operetta amplifier was quite beautiful. My sample was black with a mirrored back finish around the large Operetta logo. It is a relatively modern look but mixed quite nicely in my traditionally styled listening room. Score one for the wife acceptance factor.





How does it sound?

The Jaton AP2140A (it comes in black, too, as you can see) has a tight yet hefty bottom end, a transparent articulate midrange, delicate highs, razor sharp imaging, and is dead silent when there is nothing to play. It was never bright or edgy and the bass emphasis came through nicely. If the bass was not so accurate, this could have been a detriment but I found it enjoyable. Given it's price range, a little listening session with some friends included comparing the Jaton to some older affordable offerings. The Adcom GFA 535II and a Carver M200t were embarrassed by the Jaton to the point where we'll just skip up a class in amplification. Think affordable high end. I was wrong to compare it to the lesser quality items.

My Forte Model 5 is an older affordable relatively high end amplifier biased a bit into class A. For reference, it uses 94 watts at idle whereas the Jaton uses about 1 watt at idle. The Forte Model 5 is lean in the bass but with a slightly exaggerated midbass, a liquid laid back midrange, and open rolled off highs. The differences were large. In short listening sessions of an hour or two, the Jaton was the clear champion. It's sense of energy, strong bass, transparency, and heightened clarity was great fun. For really long listening sessions the Forte Model 5 sounds more palpable. You're never taken aback by a wailing guitar, energetic viola, or ripping horn yet you could listen all day not realizing what you've missed. The Forte has sins of omission verses commission. My wife and I were at odds here. She listens at low levels for long periods of time while reading, doing projects at home, etc, but never sits to listen critically. She just wants music without any hint of annoyance. I will do the same at times but also really enjoy recreating the music as accurately and realistically as possible, sometimes very loudly. She chose the Forte, indicating that she thought the Jaton sounded too perfect. I chose the Jaton.

At its price point, it would be unfair to compare it to some of the big guys costing thousands more but if I were to, I would have to say that the Jaton could be a bit more liquid. In fairness, we'll compare the Jaton Operetta amplifier to the Bryston 2B SST. Bryston's SST series of amplifiers really took them to the next level of refinement. Those who have heard the originals or the ST series should listen to the SST series before judging. The amplifier section of the Bryston B100 SST is essentially the Bryston 2B SST and that is what I used for reference. What was surprising was how close the Bryston 2B SST and the Jaton Operetta amplifier sounded. Both of them share a strong bass characteristic, and the same open transparency yet the Bryston, at two and a half times the price, is more forgiving and refined in the high end.

The Jaton sounded much more powerful than the 70 wpc rating but the Bryston actually hits 130 wpc into 8ohms in testing and the difference is audiable. While playing “Come On” from Stanley Clark's “Toys of Men”, I could bottom the woofers of my speakers but not with the Jaton. Note that this is likely more of a power rating difference as the Jaton's bass sounded tighter and stronger than the Bryston's. The Jaton provided a huge sense of dynamics and energy with complete control. In “Hmm Hmm” from the same album, the twang of the bass guitar string is exceedingly life like. The following song mixes some of his old Jazz fusion with a modern funky twist. It also rocks when played through the Jaton in comparison with the Forte. Read our review of this CD compared to two others by bass masters Marcus Miller and Victor Wooten. Link at end of this review - publisher

I broke out an old favorite; “Live at Blues Alley” from Eva Cassidy. The first thing I noticed was how much it sounded like a live performance in a relatively intimate setting with a sound slightly larger than some concerts I used to frequent in smaller venues. I was intrigued enough to look into “Blues Alley”. It is a small 18th Century red brick carriage house seating up to 125 people for dinner and a show. I was close.

The Jaton is very accurate. “Stormy Monday” from the same album exemplifies the great soundstage and accuracy. One can also hear the effect of the “professional” speakers horn tweeters on Eva's voice. Note that not all horn tweeters have that sort of honky upper midrange sound. A recent review of the HSU HB1 Mk2 speakers was a reminder of that. Overall, “Live at Blues Alley” from Eva Cassidy was quite enjoyable when using the Jaton.



Sometimes I like to purchase compilations from Delos International. It's a great way to find new music that you may like and they usually sound great. I plopped “Second Stage”, “The Symphonic Sound Stage, Vol 2” into my transport and gave it a whirl. I was particularly drawn into the experience instead of my mind wandering off in different directions. The instrument placement seemed very explicit. The audiophile in me pushed the music lover aside and pulled out the liner notes. What I found was that the imaging was laser accurate, and easily showed the difference between the violins and violas which were placed next to each other on stage. The sense of space was very apparent to a point where it almost seemed too perfect. The Jaton AP2140A was nearly explosive in Fireworks. I had to remind myself that this was only a 70wpc amplifier. One interesting finding here was that the Jaton sets the listener back a row or two from the stage than I am used to.

The Jaton Rocks, plain and simple. This is, of course, if 70wpc is enough for you. I played countless classic rock albums and was consistently the same. Highly accurate reproduction of raspy guitars, saxophones, and drums with a hefty bottom end and voices ever so slightly recessed. I had to look further. “Second Edition” from “Public Image Limited” is essentially a bunch of what I call; “angry sad guy music”. Haunting lyrics combine with a mind numbing beat with lots of echo. Many amplifiers would fail this one. I have seen amplifiers fall apart without enough reserve power for the continuous pounding bass. I have seen amplifiers sound boomy and sloppy. Two examples of this are “Albatross” and “Careering”. The bass is strong and tight and the room sounds as if it's three stories high and relatively empty. It's not annoying and just as raspy as it sounds through headphones.



The Jaton Operetta AP2140A is a great sounding amplifier and exceedingly beautiful too. With everything I threw at it, the fan either never turned on or I could not tell. It ran consistently cool and strong. At $1000 it is an affordable alternative to a Bryston 2B SST but without the 20 year warranty. The Jaton sounds very good for the money. Jaton thinks that having a much lower profit margin and selling more amplifiers may be a better business plan. Maybe they are on to something. The closest thing I can think of is actually an integrated. The Xindak XA6950 class A amplifier cost just $300 more and sounds better. It mixes the liquid ease of the Forte Model 5 with the energy, detail, and transparency of the Bryston and Jaton. One must also consider the Xindak's lack of flexibility and dealer network however. The Jaton, however, is made by a company based in the United States which may be a plus for those nervous about longevity. I can easily recommend the Jaton AP2140A Operetta amplifier. I nearly bought it without even needing one.


140wpc into 4 ohms
70wpc into 8 ohms
THD + N < 0.01% @ 4Ohm 1 kHz, 140 Watts
Frequency Response 16Hz-40Khz, +/- 3db
Max Output Level 23 Vrms
Input Sensitivity 84 mVrms
Dynamic Range 150db
Max Gain 30db
Max Power Consumption 950 watts
Input Impedance 55 k Ohm
Dimensions 17” x 7.5” x 14.5”
Weight 47 lbs

CD reviews of Stanley Clarke, Marcus Miller and Victor Wooten