This is just a brief listen over a few days of this ES amplifier from Sony. I have a few amps, mostly separates these days, and I’m a big Sony fan. Particular interest is in “VFET amps”, not only Sony vfets. I just find these amps very interesting, the history around the devices is quite remarkable and the sound is pretty special too. No VFETS represented here, but we do have fets in the form of MOSFETS. I have been interested in the later (MOSFET) Sony ES line for a long time, and finally acquired an integrated from Japan. Sony TA-F333esJ - 1992 The esJ is the last iteration in the ES line from the sixth generation of ES integrated amplifiers. Sony of course made all types of audio products marketed as ES. The ES CD spinners amongst their best sellers. This amplifier is rated at 100w into 8ohms. It weighs 21.3kg. There is a slightly more powerful 555esJ model, at 120watts and 24.6kg. Cosmetically, the esJ was, in my opinion, the last in the ‘luxury line” of integrated amps from Sony. It is beautifully made, consisting of the G chassis, heavy build, and finished to a very high standard. Audio grade and boutique parts are used throughout. Though the ES line continued after the esJ for another 7 years, the build quality was not as good. The later TA-FA33ES, for example, shedding some 10kg in weight, and looking decidedly different. The amp was made in Japan in 1992/93. ES is generally referred to as “Extremely High Standard”, though this actual wording was not seen on any Sony products until this sixth generation dating from 1985. I will not bore you with all the export designations that started with this series, suffice to say the export equivalent of this amplifier is the TA-F707ES. As far as I can ascertain, there are a few differences with the export model. Being a pair of pre-outs, different top plate, and the export is rated at 90watts? Loads of information on Sony ES here. http://www.thevintageknob.org/sony-ES.html The 333esJ is the first ES integrated amplifier where Sony adopted the MOSFET devices in the driver stages and the output stage to give an all fet delivery from input to output, (power fets in the form of vfets were first used by Sony as early as 1974 in the TA-4650 integrated amplifier). For ES, Sony continued this design until 1998 with the TA-FA777ES, the end of the series. Topology The power amplifier is a cascode design. Sony first used this design in their legendary TA-N7B power amplifier (one of which I have) back in 1977. That was cascode vfet and bjt’s at the output stage. A remarkable and complex design. Sony continued to develop and evolve this design right up to this point in the ES series. The object of all amplifiers (power amplifiers) is to reduce distortion, whilst maintaining linearity. Cascode does this by eliminating voltage induced distortions whilst increasing bandwidth. High bandwidth means more speed and dynamics, which should translate to a great sounding amplifier! Sound The MOSFET power output devices, there are a total of eight, benefit from this design, and the sound is exceptional. This is the reason, why when I first heard this amplifier it immediately reminded me of the TA-N7B. Now we know why. It is a high speed, low distortion amplifier. The basic performance is very high. Nicely balanced, with great control and with what appears to be quite large power reserves. The Sony drives the Orpheus Apollo to ear splitting levels if required. I was very surprised by the performance of this amplifier. This is another very nice piece from Sony, which is sounding really good now, but even better after a restoration.