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Marantz PM-90 Review (Vintage Amplifier)


Jan 17, 2020
Hello friends,

Sony TA-A1ES has been a really long-selling quasi class-A integrated amp in audio scene, and it is still manufactured and widely available at least in Japan. It has been occupying a unique position in the market for long period after its launch in 2013. I hope your web browser would properly translate this comprehensive page on TA-A1ES and also this spec page into English.

In December last year, I became much interested in SONY's description of;
"The TA-A1ES uses a current feedback type power amplifier to achieve a sound with excellent focus of the sound image without phase rotation up to the ultra-high range. "
(This looks somewhat similar to Accuphase's description for A-36 as shared here.)
"In addition, by applying sufficient bias, the heat generation of the transistor becomes almost constant, there is no sudden temperature change at the semiconductor chip level, phase rotation in the ultra-high range is suppressed, you can enjoy a sound with good focus, and the emitter resistance is deleted. "

In January this year, therefore, I intensively evaluated TA-A1ES in my multichannel multi-driver multi-way multi-amplifier project, as shared in my posts #307 through #309 on the thread. Then I finally decided to use TA-A1ES to directly and dedicatedly drive Be-tweeters and metal horn super tweeters in my multichannel multi-way system as sharted in my post #311 there.

In my latest system configuration, TA-A1ES is dedicatedly driving Be-tweeters, and Yamaha A-S301 is dedicatedly driving metal horn super tweeters Fostex T925A.

I found and confirmed the quasi class-A operation of TA-A1ES is really nice in driving high Fq efficient SP drivers in multi-driver multi-way system, even though we should be careful about its physical layout since the top cover would be rather warm in quasi class-A configuration.
I wasn't trying to knock the TA-A1ES an I mentioned it as one of the exceptions from current-day Sony product line. It seems to have been discontinued/short on stock in the US, glad to heard that it is still kicking strong in Japan :) I also had the matching HAP-Z1ES which was one of the audio pieces I kept for longer than 5 years (2014-2019). Just recently sold it as I like to use Roon more.

I actually had the TA-A1ES for 2 years (2014-2016). It's actually one of my first true hi-fi piece. As you mentioned it is smooth sounding while staying dynamic enough with higher efficiency speakers. I used it on various KEF speakers back then.

One interesting fact about the current transfer function of the amp, it's likely a descendent from their good-old-day 80s technology. They used to call it "Audio Current Transfer": http://www.thevintageknob.org/sony-TA-F555ES.html

Now if we can get a sample of the TA-FA777ES, that would complete my Sony adventure. Even that now I moved to the overpriced components (Nagra), I still have a Sony PS-X600 turntable connected to the Nagra stack. 80s and 90s were the golden days of Sony hi-end, and Japanese Hi-End in general.


Major Contributor
Forum Donor
Feb 29, 2020
Ichihara City, Chiba Prefecture, Japan
80s and 90s were the golden days of Sony hi-end, and Japanese Hi-End in general.

Yes, I fully agree, and I feel much nostalgia for that era of Hi-end audio in Japan...
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