Author Topic: Sansui-AU 111 revisited  (Read 10639 times)

Online King_Julian_S

Re: Sansui-AU 111 revisited
« Reply #15 on: June 15, 2015, 09:34:19 AM »
A wise old man with lotso experience told me that the phono is not great and that the strengths is really is the line and power stages...
That got me thinking to try each section ...
So to be honest the pre is not bad at all...
It just irritated me with all that flexibility ... Lol... I think if you give me a button to fiddle with then Inwill never rest 😂😂😂... And this pre really have no shortage of function as you might know..

So I tried a highish end pre-amp , which I really wanted to sell in order to help recover some funding for the AU, but now I don't really see myself selling it ... It is really so much nicer then the AU pre section and I think it showed me just how great that power section really is...

I want to try it also with another higher end pre and see what the results is....

So , the way I see it... If you are restoring one for real use of its great sound quality and not just for nostalgic reasons and you have a bit of a budget pinch , then maybe it's worthwhile to perhaps do the sections in a priority to get most bang for your bucs ...
What this means , and of possible to do it in such a fashion , is that if I had to get one restored is that I would spend most bucs in the power section and make sure that is as optimal as possible , 2nd I would do the pre section and lastly the phono stage of needed... But honestly I think one can get far better benefit and real quality from that power section of you use it with a seperate pre of very high quality and even a seperate phonostage in the end...

Hope that makes sense ...
All IMO and just my taste and experience listening to this great ofcourse...
Non audiophile music lover...

Offline Ampdog

Re: Sansui-AU 111 revisited
« Reply #16 on: June 15, 2015, 10:47:47 AM »
Thanks King_Julian, thanks Hennie.

As said earlier (and having earned flac from committed subjectivists), people's hearing experiences are in the ears-of-the-beholder, and this literally so, and no offence intended. I mentioned that I 'tailor' the phono stage somewhat but that primarily with regard to install a l.f. cut-off characteristic below audio. I really found nothing the matter with the phono stage; the equalisation is accurate enough, and for attributed 'black magic' regarding 'sound of', sorry. (Fortunately it will be off-topic to start on that! I modestly believe I had at least as much experience with those over 60 years as anybody   :) )  I do replace the input transistor with a BC550 - not a drop-in; one has to slightly adjust the dc working point for optimality (which is ... never mind).

Also, inasmuch as most pre-amplifiers have some tonal characteristic or other, I would ask for a detailed description at least before starting to consider real advantages/disadvantages. Yes, there are overly many adjustments available; such was the selling factor of the time - also with other amplifiers. (The AU111 execution is superior to most.) But adjusted to "flat", the pre-amp is simply that, and with no audible distortion. Those are the first matters one examine. Other than that, be my guest. Even as far as 'voicing' is concerned, one cannot have more freedom to finely adjust tonal balance to one's taste than with the AH-111!


[Caveat as accentuated to all I come into contact with: Refrain from using the present "Presence" switch. It is in the wrong place in the circuit, and can cause spurious overload in the power amplifier to the point of shortening the life of the 6L6GCs, depending.

One does not put any frequency discriminating circuits in a properly designed half-decent power amplifier circuit! 

This one accentuates lower frequencies around 150 Hz, something I never associated with "presence".  Presence to me is rather a slight shelf-increase upward from some 1 kHz. What makes more sense is keeping on the loudness feature permanently. (I would apologise to past clients where I did not move that "Presence" feature to a more suitable place in the circuit; of which there are plenty. I have offered to do that for all AU-111 owners I know for free should they be able to get their amplifiers to me for a day.)]
Audio must be the only branch of engineering where lack of basics' knowledge is considered a superior form of wisdom. (Anon)

Online King_Julian_S

Re: Sansui-AU 111 revisited
« Reply #17 on: June 15, 2015, 11:17:06 AM »
Noted Johan...

Thanks for the input as well , much appreciated and nice to know the truth...
Hence I was very careful to say that "IMO" because I know for sure it's certainly just perhaps my preference or even those Lowthers which makes it something I preffered in the end...

Will still bring it around to you as soon as I can get to convince myself that I can live without the AU for atleast a day or two 😂😂😂... It's hard to even imagine as I use that more then my main system these days with the leak throughline connected ... I'm sure you understand my e theme predicament which other night not immediately understand ...lol...

Keep well and apologies again for derailing a bit ...
 
Non audiophile music lover...

Offline henniekuyper

Re: Sansui-AU 111 revisited
« Reply #18 on: June 16, 2015, 12:31:12 PM »
Thanks KJS and Ampdog

Much appreciated conversation. I do agree with both of you.
I do not use my Au-111 with presence.

Regards
Hennie


Offline charles

Re: Sansui-AU 111 revisited
« Reply #19 on: June 16, 2015, 04:23:52 PM »
Hennie, it is very good to hear from you.

It is time that I start using my Sansui BA 303

http://www.avforums.co.za/index.php/topic,38776.0.html

Online Francois

Re: Sansui-AU 111 revisited
« Reply #20 on: June 16, 2015, 10:45:23 PM »
Oom Johan,

How on earth did you get the courage to modify that mess?!.

I opened mine, had a 5min long look at it, decided to hell with it, I'll just replace few select components. The bloody ones I can reach... :sd:

For the rest....no way!
I was born analog, not digit by digit....

Offline Family_Dog

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Re: Sansui-AU 111 revisited
« Reply #21 on: June 17, 2015, 07:02:31 AM »
Francois - accept the challenge! Practice on yours first and then I'll bring one or two more for you to do!  ;)


-F_D



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That Guy in South Africa...
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Offline valvesound

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Re: Sansui-AU 111 revisited
« Reply #22 on: June 17, 2015, 09:03:39 AM »
Oom Johan,

How on earth did you get the courage to modify that mess?!.

I opened mine, had a 5min long look at it, decided to hell with it, I'll just replace few select components. The bloody ones I can reach... :sd:

For the rest....no way!


Hi Francois.....post us a pic of the intestines  :BWAHAHAH: 
Please contact me if you are interested in any of my products to transform your enjoyment and experience of high end stereo

Online Francois

Re: Sansui-AU 111 revisited
« Reply #23 on: June 17, 2015, 06:13:36 PM »
I will when I start to replace few things... for now she is happily playing away...
I was born analog, not digit by digit....

Offline Ampdog

Re: Sansui-AU 111 revisited
« Reply #24 on: June 17, 2015, 08:48:33 PM »

Hi Francois.....post us a pic of the intestines  :BWAHAHAH:

A 'before' and 'after' somewhere here on the forum; can't seem to locate those now.
Just to inspire Francois.

Yep. I ended up by removing the lot. Over many months. Great 'medication' at the time for curing some depression caused by my fellow citizens. I can recommend it (that and winding a transformer).


Advice to Francois and F_D: Keep notes and photos of where stuff went, and draw out what/how you want to change/relocate first. I have my notes in a folder here - all some 20 odd sheets of that.
Now what bid do I have for those ...   Oops sorry
Audio must be the only branch of engineering where lack of basics' knowledge is considered a superior form of wisdom. (Anon)

Offline Ampdog

Re: Sansui-AU 111 revisited
« Reply #25 on: June 17, 2015, 08:52:10 PM »
One does not put any frequency discriminating circuits in a properly designed half-decent power amplifier circuit! 

Apology folks, I need to correct/qualify that.

I meant inside the main (global) NFB-loop of a power amplifier proper.
« Last Edit: June 17, 2015, 08:54:46 PM by Ampdog »
Audio must be the only branch of engineering where lack of basics' knowledge is considered a superior form of wisdom. (Anon)

Online King_Julian_S

Re: Sansui-AU 111 revisited
« Reply #26 on: June 18, 2015, 08:41:52 AM »
Half decent 😄😄😂...
And here I was thinking this thing is full decent  ....
Non audiophile music lover...

Offline Ampdog

Re: Sansui-AU 111 revisited
« Reply #27 on: June 25, 2015, 08:00:36 PM »
Remove that objectionable "Presence" feature (or rather 'transplant' it to somewhere else in the circuit) and I will retract the "half-"  but that's just me. We will grant Mr Oushima a little slip - others have done worse. If not there, what would remain for tweekers to change?

Audio must be the only branch of engineering where lack of basics' knowledge is considered a superior form of wisdom. (Anon)

Online King_Julian_S

Re: Sansui-AU 111 revisited
« Reply #28 on: June 26, 2015, 06:11:17 PM »
lol ....
Tell me , is leaving the switch off the same as physically removing/bypassing it ?
In that case it's a simple mod ... Just never switch it on then....
 There is a lot of buttons and switches to keep one busy for an eternity allready...

Non audiophile music lover...

Offline Ampdog

Re: Sansui-AU 111 revisited
« Reply #29 on: July 01, 2015, 03:38:00 AM »
Leaving the switch 'off' is the same as bypassing it, as in shorting the appropriate sets of contacts, not removing it (leaving them open). But some NFB signal-carrying leads go to the front panel and back; rather better to remove the feature at the tie-point strip inside the chassis, plus supersonic stability checking. (Sounds complicated, is not.)

Yes, there are enough other options as you say. Round about 1955 - 1970 various tone options were the "in" thing, leading to sometimes unnecessary extravagance of options. I would not accuse designer Oshima of succumbing to sales gimmicks; let us just say that he went to the extreme of still useful options.

(OT: Note another often ridiculous 'extreme' of up to a few years earlier, before the universal RIAA phono equalising characteristic was finally adopted. I can't recall the brand, but one amplifier had 5 separate l.f. and 5 h.f. options available - on separate switches - as in a total of 25 different combinations; all within an envelope of a few dB!  We think cable discussions are never-ending; you should have read the heated discussions round which one of all those phono options was the best!)

Still, Julian, it seems a waste to just leave a front panel switch as a decoration. As said previously, it is quite simple to incorporate the same feature in one of the pre-amp stages, at least giving a real 'presence' feature.
Audio must be the only branch of engineering where lack of basics' knowledge is considered a superior form of wisdom. (Anon)