Power Amplifiers

Jaton Operetta 2300a Class A/B Amplifier - First Look

ARTICLE INDEX
Jaton Operetta 2300a Amplifier

Introduction

The Jaton company has been around for over 25 years. They started with manufacturing PC video cards, and have since branched into home theater and hi-fi gear. Jaton's Lyra HD-661 DX speakers were recently reviewed at Secrets, and their interesting design and great sound made me want to try out their amplification. George Cheng from Jaton was kind enough to send me a rather large and heavy Class A/B Stereo amplifier capable of putting out 300 watts RMS per channel into 4 ohms. Initial problems with the amplifier has required Jaton to redesign it, and the revised version will be sent to me for review. In the meantime, here are some initial observations on the unrevised unit.

Specifications

  • Design: Class A/B Stereo Power Amplifier
  • Power: 150 Watts RMS x 2 into 8 Ohms, 300 Watts RMS x 2 into 4 Ohms
  • MFR: 16 Hz - 40 kHz, ± 3 dB
  • THD+N: < 0.01% @ 8 Ohm, 1 kHz, 150 Watts
  • Inputs: Unbalanced RCA
  • Dimensions: 7.5" H x 17" W x 14.5" D
  • Weight 80 Pounds
  • MSRP $6,000 USA
  • Jaton

Due to the inherently low efficiency of the Class A topology, in order to get 300 watts output (2 x 150 watts stereo at 8 ohms), you need to consume at least twice that, and the extra power is dissipated as heat. Big heat sinks are needed to expel this energy, and these take up lots of real estate. Jaton claims that the Operetta 2300a stays in Class A operation through about 90% of its operating range. While this is impressive, and may allow the amplifier to run in Class A for most of its operation, it is not a "pure" Class A amplifier, rather a Class A/B. Not that this is a problem mind you, unless of course you think you really need 300 watts of Class A power. While there is a theoretical sound quality problem when switching from Class A to Class B (crossover distortion) in practice this is not audible (depending on who you ask). What you do get is an increase in efficiency which allows you to reduce the overall size.

Jaton Operetta 2300a Amplifier