Sansui AU-555

[Thom PC]

I have the opportunity to buy a vintage Sansui AU-555 integrated amp. Mainly because I think it could be fun to play around with some vintage gear, and I think it looks cool. It would probably be assigned the job of driving a set of Rogers LS4a/2 speakers instead of the current Creek 5250R int. amp. Can anyone tell me anything about the Sansui - is it any good, how long can I expect it to last now that it is some 30-35 years old, and if it fails, is it likely to be repairable?

Thanks, Thom

 

[jonclancy]

Some info here: http://www.classicsansui.net/ 60WPC it seems.

Also, try over at Audiokarma.

I've got a couple of old Sansui amps (though lower down the product range) and they still work, and look simple enough inside as well.

HTH

Jon

 

[royce5]

Hi Thom,

I am a very satisfied owner of the AU-555a, it is a great little amp, like the Marantz 1060 or Naits, these "baby of the range" seems to a distillation of the designer's craft.

One thing you need to know about Sansui's is that each model are crafted with a different sound in mind, if you like the sound of the 555, you might not like any other models, so don't think models like 666 or 888 are just more powerful versions of 555.

The "triple digit" series are quite easy to maintain according to the repairman, as they were designed/built whilst Sansui were still making valve amps and they are supposedly just "valve amp with transistors in place of valves".

You would need to get someone to re-cap it and if you want to get tweaky, get them to resolder on a better quality mains cable, cleaning the contacts with DeOxit, that's about it.

555 and 777 are similar in sound, in that they are almost "SET" valve like, bass is a little lean, the sound pitched towards the midrange up, it is bright but in a good way (not edgy)

555a, 666, 888 are similar, these are more neutral, quite Nait-like, a little punchier, more balanced, a little warmer.

Au-999 combines the best of both

With the Rogers, any of them should be fine, depending on your tastes.

The AU-555a in my system replaced my Naim 72/180 driving Kans Mk 1.

innards of the AU999 from the same era, this shows the amp's simplicity

 

[emzdogz]

hello, could someone tell me, please, if it is important or necessary to have those 2 u-shaped pins which connect across the pre amp outs and main in? (as shown in photo in above post)
I have lost those pieces...there is currently nothing in those holes at all.

My amp does need repair, in any case.
thanks!

 

[Uncle Ants]

It is important. They connect the amp's preamp section to the power amp section, so you can uses it as an integrated or as a pre or a power. If lost, short interconnects will work fine

 

[hifi_dave]

They connect the pre section to the power amp section and you will get no sound if they are not in place, unless they have been strapped across internally. You can join externally with a decent incon for an improvement in sound. IMO

 

[hifi_dave]

Uncle,
Snap.

 

[emzdogz]

wow, thanks! maybe I don't need a repair after all!

 

[emzdogz]

Here is my AU-555a with TU-666 tuner. Now that I bridged the pre-amp to the amplifier section, I have sound. But it is kind of muddy sound. Also, music from my computer (iTunes on iMac or MacBook) plays at very low level connected through AUX input.

Maybe it still needs repair after all. Also the loudness switch and the low and hi filters don't seem to do anything.

thx again for the above responses.

 

[Uncle Ants]

It sounds like it needs some work certainly. Depending on the material and the setup the low filter may not do anything noticeable anyway and possibly the high filter as well, but the loudness switch should most definitely do something noticeable. It certainly shouldn't really sound muddy.

 

[emzdogz]

It sounds like it needs some work certainly. Depending on the material and the setup the low filter may not do anything noticeable anyway and possibly the high filter as well, but the loudness switch should most definitely do something noticeable. It certainly shouldn't really sound muddy.

hi Uncle Ants, what would be a good way of addressing this with the repair shop? If I go into a repair place and say that in addition to crackly knobs the sound also sounds kind of muddy and not wide open...it just seems like those things are so subjective...
anything come to mind that I could ask them to check, specifically?

Also, when a shop goes through an old unit can they check things when they're done like for instance measure the THD, or some other measure of distortion? Is it possible to check by measuring, how clean the signal is that the amp is making?

I found a way to set iTunes in my computer so that it is much better now when connected to this amp.

Might just be an issue of getting used to listening to actual speakers again after many months of headphones only. The other thing is that oddly, the amp seems to be getting better as I use it. Less noise in the knobs and switches, etc.

Anyway if what I'm asking doesn't make sense, please feel free to ignore...

and thanks again!

 

[Uncle Ants]

The knobs could well get better with use if they hadn't been used for a while. Give them a good twiddle while it's off and it could go altogether - a squirt of contact cleaner will help.

As to the rest. It's about 40 years old and a lot of the capacitors are likely on their last legs. Replacing those would be the first port of call.

 

[emzdogz]

The knobs could well get better with use if they hadn't been used for a while. Give them a good twiddle while it's off and it could go altogether - a squirt of contact cleaner will help.

As to the rest. It's about 40 years old and a lot of the capacitors are likely on their last legs. Replacing those would be the first port of call.

OK thanks!
btw, have been enjoying reading some of the links in your footnote link. Re: digital vs. vinyl.