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Sansui AU-555A

Solid State Stereo Control Amplifier (1971-73)

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Sansui AU-555A


In design, appearance and performance, the amplifier draws heavily on the careful engineering that has made Sansui's larger AU amplifiers, favourites among stereo enthusiasts throughout the world.

The AU-555A is an upgraded model of the AU-555, featuring refined dull black panels and the exclusive triple tone controls.


Power output: 25 watts per channel into 8Ω (stereo)

Frequency response: 20Hz to 30kHz

Total harmonic distortion: 0.5%

Damping factor: 50

Input sensitivity: 2mV (MM), 180mV (DIN), 180mV (line)

Signal to noise ratio: 70dB (MM), 80dB (line)

Channel separation: 45dB (MM), 50dB (line)

Output: 180mV (line), 30mV (DIN)

Speaker load impedance: 4Ω to 16Ω

Semiconductors: 23 x transistors, 2 x diodes

Dimensions: 395 x 127 x 278mm

Weight: 8kg


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Reviewed Dec 03rd, 2019 by Jgun

I am glad this is my first amp a fully recapped version, Phono plays super silent - no hum whatsoever.

Very versatile when used with my excellent piano2.1 player from allo.com.

Paired with Technics SB-E100 speakers from early 70s barely crosses 9pm mark in the volume knob for loud listening. This amp definitely packs more power.

Reviewed Jun 11th, 2019 by Gian Piero Gerbella

I had many low and medium level amplifiers, both in terms of price (current) and performance (Marantz 1090, Akai AM 2600, Sansui Au 217, JVC A-s3, Philips Sound Project 8000 for example) but only one type of speakers : the German pneumatic suspension (Grundig HIFI Box 350 and Canton GLE 50 / C 850, Karat 100). Well, the Sansui 555a coupled with these speakers is impressive in detail, dynamics, power output by just shifting the volume knob to 9 o'clock. And the Canton and Grundig speakers are not exactly easy (but they are also impressive). He will surely survive me.

Reviewed Feb 05th, 2019 by Rotobadger

Just got mine. Fantastic sounding and surprising amount of “punch” for 25wpc. Will be keeping this one. Feels like I got a tube amp without the cost of getting a tube amp!

Reviewed May 29th, 2018 by uazza

near tubes sound. exellent dynamic and powerful bass ,crystal medium and high frequencies.
the state of the art f amplifier low/medium power

Reviewed May 06th, 2018 by JOVA

awesome sound. incredible dynamics. extraordinary in highs and medium levels with perfectly adjusted bass. surprising.



re: AU-555A

Just received a recaped Sansui AU-555A. Coming from English hi-fi (Naim/Linn) which did not convince me with rock music, I find this amp really impressive! I don't know how tubes amp should sound, but this amp is definitely warm, yet detailled and punchy.
Awesome listening for a 50 yo device!
Highly recommended!

My First AU-555A

What a remarkable amp! I've owned quite a few amps and receivers in my life but I can honestly say this little gem outshines them all! Who needs the bells and whistles of the latest techno-crap.
Nothing like pure, old school sonic clarity.

re: AU-555A

I just got one these recapped and refurbished. The sound is stunning! Highly recommended.

This website is not affiliated with or sponsored by Sansui. To purchase AU-555A spares or accessories, please contact the company via their website or visit an authorised retailer.