January 2012

World Premiere!
Jaton Operetta A2300AX Stereo Power Amplifier
A glorious combination of warmth yet with a good dose of neutrality too.
Review By A. Colin Flood

  We know that most loudspeakers require an enormous amount of energy. No, make that most music requires an enormous amount of energy. No, make that most loudspeakers require an enormous amount of energy to make music. An audiophile quality loudspeaker, with a fairly typical 85dB/W/m efficiency, may require less than a watt to reproduce conversational sound pressure levels (SPL) about 10 feet away, yet for brief microseconds musical peaks 30dB higher at full volume can require as much 4000 watts!

Tweaking audiophiles deal with this problem three ways:

1. Play music at moderate levels. I recently heard a complete Quad system. The sound of its music could make Julie Andrews jealous. But the system couldn’t replicate rock concert SPLs cleanly; it can’t party like a PA.

2. Use uber-efficient loudspeakers, like my Big Ole Horns (see Reviewer’s Bio*). These 104dB/W/m behemoths require only 60 watts to play 40dB peaks!

3. Use outrageous wattage monster amplifiers like the Boulder 3050

Founded in 1983 in Taiwan, Jaton ('je,ton) relocated to San Francisco in 1988. Their system has a Operetta RC2000P pre-amplifier and REAL A3 loudspeaker (review coming). In a fashion, their new system attempts to resolve the power problem of music reproduction all three ways:

1. It doesn’t try to be the loudest system possible.

2. The A3 loudspeaker is more efficient than average, with 89dB/W/m efficiency.

3. So with 300 Watts into 4 Ohms, their A2300AX amplifier can cleanly power their A3 loudspeakers to 100dB musical peaks

The Class A designation for amplifiers means that 100% of the input signal is used all the time. The active elements remain conducting. There is no quick microsecond switching off and on. Class A amplifiers are typically more linear and less complex than other types, but are very energy inefficient. They are clean sounding, but consume electricity.

George Cheng, Product Manager, answered my questions. He says the model name means AP, for amplifier; the 2300 designation means two channel with a total of 300 watts at 8 Ohms. The AX appellation means it is analog design with XLR input. Cheng says the design concept of the Operetta amplifier is to push the highest gain out of the parts and circuit design, in the same time, eliminate the most noise and modulation distortion. "In generally," he says, "you don't need a very active signal in order to get the detail and richness with Operetta amplifiers compare to other amplifiers."

There isn’t an iPod and PC analog input, there is no space for it, but a passive pre-amp will work well. The Operetta amplifier is stable with 4 Ohm loads. Cheng does recommend 20 Ampere electrical service. The amplifier needs air space around it (tube amplifiers require about two feet on all sides for proper air circulation). It did get a mite warm, but never hot. In fact, I eventually placed my bass amplifier on top of it and never worried about the Operetta getting hot. The stereo channels cannot be strapped together to provide even more power. Cheng said "the two-stage design can maintain the warmest of Class A design and also prevents the generating of heat. First the voltage IC stage and then the current Darlington stage." The Operetta amplifier has a fan so quiet I never noticed it was on. It automatically turns on when temperature heats up. There is an output relay which will shut-off the amplifier to protect it and the loudspeaker. Unfortunately, their control unit won't shut-off or put the power amplifier into stand-by mode.

He said "It took us a long time to find the balance of these two stages design. Sometimes it generates too much of the heat and even burn the Darlington out and sometimes it doesn’t have enough power output. Especially the feedback circle of Darlington stage really caused a lot of time and effort to final its definition." Jaton loves Mundorf components as they are using six of Mundorf capacitors just for the two feedback circle to make the Darlington stage powerful yet operate cool after playing for days. Jaton took nearly two years to achieve their goal and find the balance of two stage amplifications and define its circle too.

The front panel has a shining blue power indicator, to remind you of who is providing the musical pleasure. The speaker cable binding posts are on opposite corners of the amplifier, which provides room to attach my thick Coincident rattlesnakes, but the posts are covered with a clear plastic shield. The shield makes attaching a loudspeaker cable tricky, but once connected, it helps to hold the cable in place. Cheng did not know why these posts were used. To turn on this 80-pound black block of power, you have to reach across its top and down between the input cords. The power switch is located on the back. There is a tiny yellow circuit breaker next to the flip switch. It is easy to hit that button by mistake. Of course, this is no biggie if you use a line conditioner to switch your components on. Jaton fills orders in three to five working days. There are some retail stores in the States selling Jaton products. Shipping is usually by FedEx Ground unless there is a bundle shipment by trucking.

Tonality
Nothing I threw at it was out of the Operetta's league. I listen to a variety of music, including choir, as part of my "Test Discs: Reference Recordings for Subjective and Analytical Comparisons." But the closest reference country and bluegrass music is Holly Cole and Allison Krause (with Robert Plant)*. The Operetta easily handled everything thrown at it no matter which loudspeaker used.

Sub-Bass (10 Hz - 60 Hz)
When I did flip the power switch, without hitting the little yellow breaker, the Operetta always had plenty of power. Whenever I see 150 Watts into 8 Ohms doubling into 300 Watts into 4 Ohms, which the Operetta does, I think bass control. This spec makes me think the amplifier can push the woofer, not the other way around.

Mid-Bass (80 Hz - 200 Hz)
I did not have The Matrix and X-Men movies or the Nelson Pass X250* to compare, but nothing budged the Operetta. There wasn’t a feeling of oodles of reserve power, as there was with the X250 on my Big Ole Horns. Instead it was more of a calm and quiet "I can handle this" aplomb. In fact, the Operetta bass was authoritative, detailed, solid and effortless. The woofer control made for taut, accurate bass not exaggeratedly fast or numbingly slow. It was not or flabby, boomy or bouncy. The X250 had hard bass, but not with the clinical edge of typical solid-state amplifiers. I don’t think the Operetta is as hard, but I never thought it had that solid-state harshness either.

Midrange (200 Hz - 3,000 Hz)
The Operetta’s unassuming looks reflect its sound. My audio club acknowledged the generally neutral sound of the Jaton pre-amplifier*. The amplifier is the same even-handed balance. However, the combination of the two was not magical. Call me a tubie. As it has so many times before, Diana Krall's Stepping Out*, still part of my reference stack, continued to send me into clouds of alpha state. The flute test on DMP does DSD passed with flying colors. The Operetta sound is not dry. Even saxophones sounded wonderfully natural. They did not have the blare of the bell, but they did have rasp of the reed. The Operetta did not bang drums as hard as I remember the X250 did, but they knocked and thumped.

High-Frequencies (3,000 Hz on up)
It doesn’t seem fair to describe the sound of one super-amplifier as different than another. Its like sitting on a South Beach bench splitting hairs between the Lamborghinis and Ferraris idling by; to the casual observer, there is nary a paycheck of difference between them. Yet, I would generalize the X250 treble as more of a cowbell clang than the triangle ring of the Operetta. Both are pleasing. Attack seemed a bit slower than tube amplifiers, but in other respects, The Operetta was above average. Solid-state amplifiers can hold a note. Again, memory gives the edge to the X250. But if you are considering Jaton’s A3 speakers, I don’t think this edge is enough to consider the X250 over the Operetta. As you will see in my upcoming review, the Operetta and A3 combination works great together.

Soundscape
All the music had range and extension. Multiple instruments played as if each had their own speaker and amplifiers. The Operetta did not mash the chorus together. There was no lack of resources for musicians to draw upon.

Imaging
When I paired the Operetta with my tube pre-amplifier, a world of wonderful music opened up for me. On either the single driver Supravox Carla towers* or their A3 loudspeakers, the tube and solid-state partnership created engaging, enticing enjoyment of the music. I didn’t think there was anything wrong with anything about the Operetta - there is that neutral word again - but when I swapped my Dynaco pre-amplifier into the chain, there was everything right. The figures came out of the mist, I could see the whites of their eyes; the 3D holograph was intact.

Fit And Finish
There isn’t major item to anything to note about the Operetta. It’s a big, heavy black box with a bright sapphire eye and shielded speaker cable binding posts in its corners. One little thing though, the power switch is tricky to reach. It is on the rear, between the input cords.

Self Noise
I did not notice a need for a warm-up time, but then my equipment usually stays on all weekend. I never heard the internal fan running from across the room. Only when I was over the Operetta, trying to reach that infernal power switch did I notice the soft burr of the fan.

Value For The Money
The only real objection I have to the Operetta was price. It has a lot of competition and its price is a far-flung orbit from my down-to-earth budget. With my tube preamplifier, the combination had the warm and lush midrange that tubophiles revere. Vocals with the Operetta were clear and neutral. In this respect, as well as everything else it did on these subjective tests, it is a reference grade amplifier in almost every regard. It has the power to stand aside and not be heard. Imaging extended to the 3D dimension that tubes do so well.

Summing It All Up
To sum it all up, a super-amplifier is overkill for Big Ole Horns yet it seems to be a near perfect and practical match for the Jaton A3 loudspeakers. Together they managed to do almost everything well. If you play music at moderate levels and/or above-average efficiency loudspeakers, if an outrageous wattage monster amplifier is not an option then Jaton’s A2300AX stereo power amplifier with 300 Class A watts at 4 Ohms should make just about any tweaking audiophile happy.

Specifications
Type: Solid-state stereo power amplifier
Power: 300 Watts @ 4 Ohm, 150 Watts @ 8 Ohm, 2 Channel
THD + N %: < 0.01% @ 8 Ohm, 1 kHz, 150 Watts
Frequency Response: 16 Hz to 40 kHz (+/- 3dB)
Max Output Level: 49 V
Max Gain: 30 dB
Max Power Consumption: 1650 VA
Input Impedance: 20 kOhms RCA, 300 Ohm XLR
Input Connection: 2 of Unbalanced RCA, 2 of Balanced XLR
Output Impedance: 4, 6, 8 and 16 Ohm
Output Connection: 2 Pairs of 5 Way Binding Posts
Dimensions: 17 x 7.5 x 15 (WxHxD in inches)
Weight: 80 Lbs.
Price: $5500

Company Information
Jaton Corporation USA (Headquarters)
47677 Lakeview Blvd.
Fremont, CA 94538

Voice: (510) 933-8888
Fax: (510) 933-8889
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