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Sansui AU-777A vs all contenders

Discussion in 'Exclusively Sansui' started by smurfer77, Nov 14, 2016.

  1. The Fuxtor

    The Fuxtor AK Subscriber Subscriber

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    Good stuff! I am going to have to check and see if it's an earlier model or a later one. As far as the coupling caps, I think I read that increasing them to 4700uf will give the unit some extra ooomph in the low end...
     
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  2. smurfer77

    smurfer77 AK Subscriber Subscriber

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    I found cap type, not just value to be really important. The info and comparisons are in one of my rebuilds. Nichicon kg is a aafe bet :)
     
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  3. Yellowyoda

    Yellowyoda New Member


    Ha,Ha, well I guess you can't please all the people. The Au 70 is that a Valve design? Never had the opportunity and in the UK - even more scarce than the early solid state designs. I have heard said that their valve designs are not up to the solid state ones. This may or may not be the case of course. Must try the Au555 as it seems to punch well above it's weight class.
    Interesting about how the lower powered 777 would compare the beefier siblings the 3000A and the 5000A and like you at the levels I listen to I can't really tell a difference- perhaps this would hinge on speaker efficiency and room size. It would be good to hear them in a larger space though. Cheers, Kato
     
  4. Yellowyoda

    Yellowyoda New Member

    I'd also like to throw my hat into this one as I also have a 3000A which hopefully will get the restoration treatment, perhaps by someone more competent than myself though.
     
  5. smurfer77

    smurfer77 AK Subscriber Subscriber

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    Yes, the AU-70 is a valve design. Although the 70s solid-state units are particularly well liked, I don't think many would argue that the valve designs were not up to par. In fact the AU-777, 555A, 555, 222 and many of the Solid State receivers share very similar designs to the AU-70 era amps. And Sansui transformers were definitely great. I would say the AU-70 sounds extremely similar to the AU-777A and I can't decide if it really sounds better it is just the 'sex appeal'. The 555A is a very special unit, but if you are a bass freak it will not deliver like the 777 or 5000 (at least not without using tone controls).
     
  6. RS65

    RS65 New Member

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    Location:
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    Yelloyoda said
    Must try the Au555 as it seems to punch well above it's weight class.

    I agree totally to that. Last Tuesday i heared a AU-555 maybe better sounding as my rebuild AU-777a. A friend of mine has many different Solid State Classics. I took my rebuild AU-777a to him and we compared AU-777, AU-999, AU-777a, AU 222, AU-555 and some recapped Sonys, Kenwoods, The Fischer 505, Harman Kardon 330B and so on.
    Wonderfull Beauties...

    [​IMG]
    Some of his Sansuis:
    [​IMG]

    Now i am restoring my new AU-222 and i am searching for a nice AU-555 to rebuild.

    Greets Rainer
     
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  7. smurfer77

    smurfer77 AK Subscriber Subscriber

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    Note that the AU-555A (and closely related AU-505) is somewhat different to the AU-555 in both design and sound. In my house, the AU-555 didn't really work to my liking, as can be read in post #1. I think the AU-555 and the AU-999 are the only two models I have owned & sold off with no intent of buying again. I have somewhat revised my opinion of the AU-555 in that it does come alive a bit higher volumes (and please nobody be upset... it's just my personal opinion and remember, my room, speakers and tastes may be different so nobody should think the AU-555 is bad, it just isn't for me. The AU-999, on the other hand, is arguably flawed in stock format though).

    And to show a bit of a funny side to that last comment of two, I have bought an AU-999 to try that model again (!), as my only impression before were with 3 previous units I owned, all without the recently developed mods to correct the faulty preamp, and other improvements.
     
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  8. smurfer77

    smurfer77 AK Subscriber Subscriber

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    What is it about these darn Sansui amps that sucks you in. I was just bench testing a recapped/retransistored AU-555A. ok this particular unit been given the royal treatment; lots of new silicon, resistors, film caps everywhere I could... but when you see the size of this thing and pick it up and put it on the bench (it's a one hand job almost!), you really can't expect the glorious sound that comes out of it. While I didn't list this amp to the in true competition with the AU-777A (and now AU-70), but honestly, this thing might win the bang for buck (or weight/size) award! A little less bass control and intensity, and a slightly collapsed image in both width and depth on my setup, but really it's pretty darn amazing for the size and embarrasses most non-sansui gear :p. I guess the AU-222 will always my the 'little amp champ', but the AU-555A does deliver significantly higher fidelity for now much more weight (although I have to say, there is something about the 222's warm tone that is really really special, sounding more like those early sansui receivers (300, 350 etc) more than the integrateds in the same line up)

    So while it's maybe not my ultimate Sansui, it's really a champion in it's own right, honestly worthy of being a main amp in anyone's house that doesn't require too much more than 20 W into 8 Ohms. Well, at least that is my view now, with beer in hand and kicking back listening to the AU-555A back in the main rack (with the Sansui AU-777A, Yamaha CA-1000 & Sansui AU-70). FWIW the main amp in my other main system has been an AU-888 for over a year now. That may change though, as I need to service the AU-888 and I have a CA-F1 that is a superb preamp for a number of tube power amps I have tried it with so far.

    Ok, a bit of a rant. Long story short... AU-555A is still a champion even if it isn't in the very top of my list... I could easily live with this rebuilt one as my only amp if I had to. Maybe I should pull out a rebuilt AU-505 and compare to the 555A again. And, next up on the work bench is a beautiful AU-999; it's no secret I've been down on the 999. I suspect I've been overly harsh, but I will save my judgement for after checking it is up to spec. Will listen to it a while unmodded, then do the mods and report back.
     
    Last edited: Nov 17, 2017
  9. stereofun

    stereofun Super Member

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    The 555a was my first Sansui recap. My wife uses it with some small but large sounding Polk RTI A1. The voicing is the secret sauce imo, it always sounds good, even when hooked up to a Grace digital radio with a 1$ DA converter. Sometimes I just sit and listen to it - yes some short comings - but it does sound so musical that you forget about analyzing it. That's pretty impressive, if not the end goal.

    Once on a while I'll bring in my restored 505, I always notice the sound gets a bit suped up or "energized" with the voicing going a bit lower for an impressive gusto and presence at the lowend that really adds swing to the music. The mid stays the same, but the top end needs a bit of tweeter to try and keep up with 555a's more airy top.

    As for the 999 - a good amp stock - yet performing well below it's birthright as king of the first generation of Solid states, as well as it's superb build. Well....add in some mods and it steps into character, and rightfully takes a seat at the long table in the great Hall of audio classics as one of the truly great amplifiers. Sonics are clean and detailed, yet so smooth and analog sounding, while offering the power and speed for a wide soundstage of drive and passion.

    Like smurfer77 I have a soft spot for the 777a, which seems to offer everything that's to love about the 555a/505 (same main amp) but just scales it up in all categories:: Detail, Separation, and especially power eventhough it is only 30 vs the 555a/505 20/23. A fully restored 777a can simply drop.your jar - there is a sweet spot, once amp fully warmed up, a couple of watts below audible distortion where it transcends from being great to outstanding - where the speakers disappear and the music reaches out and surrounds you with a speed and presence that's anything you'd expect from a single rail, quasi- and cap coupled amp. As a friend said after swapping amps during a listening session: "damn, the condom just came off"..... Yes I know.... his words not mine, but he nailed it.
     
    Last edited: Nov 18, 2017
  10. RS65

    RS65 New Member

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    Smurfer77 posted
    Yesterday we compared my rebuild AU-222(Nichicon KG-M+SilmicII+WIMAs) to several other sounding beauties. Two other AU-222 (Nichicon or Panasonic recapped), AU-555, AU-999, AU-777 and AU-555a, two Kenwoods, Sony STR6060, Setton ... (all repaired if nessesairy and recapped, biased).
    Sorry the pictures are very poor...

    [​IMG]
    We checked with a direct switch between the amps.
    [​IMG]

    All the Sansuis are very near together. The repaired and full rebuild Au-999 is very very close to my AU-222, closer than the AU-555a. On lower and medium power the Au-222 sounds exactly the same, at very high levels the AU-999 has just a very very little bit more power, but the power and sound of the AU-222 is so impressive for its smallness, and for us a little bit better as the 555a.

    Here is a nude from it.

    [​IMG]

    I recapped it like my AU-777a. Bigger Nichicon Caps (Main: 4700uF/63V) and bigger SILMICs II for the power supply and 2200uF/50V coupling caps. In the next weeks i will make a comparism between my wonderfull AU-777a and my AU-222 after running him several additional hours. Yesterday my AU-777a stayed at home.
    We heared a lot of different music and my sleep on that short night was "lousy" after that. There will be not so much better sounding over that, if you understand what i mean.;-)))
    Have fun!!!
    Greets Rainer
     
    Last edited: Nov 18, 2017
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  11. gslikker

    gslikker Super Member

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    It would be very interesting reading about other comparisons, too !
     

     

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  12. smurfer77

    smurfer77 AK Subscriber Subscriber

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    That recapped AU-222 is hifi porn for me! I have to agree it's a champ. That is permanently in use in my bedroom system.

    So yesterday i put the new AU-999 on the bench, could not bias up one channel (at least, not easily... long story) and had a bit of distortion on the same channel, mainly on positive half of cycle. I'm proud to say it took a single desolder as I guessed right C820. Replaced that and output was cleaned up and was able to bias no problem. It is yes another case of where it sounds ok, but has a problem; which seems to be 90% of amps that I come across.

    Okay, it's hooked up now, and doing an initial comparison to the 777A...
     
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  13. The Fuxtor

    The Fuxtor AK Subscriber Subscriber

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    Ive just put another 555a back into my system! Seems to be destiny for me, sell one and another keeps falling in my lap! After selling off the last one i had remorse!!
     
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  14. BLAH BLAH

    BLAH BLAH Super Member

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    Just like mine in the bedroom...the little runt of the Sui Litter is...in your words...a champ!
    But..but...but...those 555A's are so nice!
     
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  15. RS65

    RS65 New Member

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    I´ve forgotten to say that i changed the Emitter Resistors of the Power Transistors from 0,47Ohm/1W to 0,68Ohm/3W metalloxids like in my AU-777a
    (Service Bulletin for the Sansui AU-777a). My Speakers are 5Ohms and because of the bigger Nichicon KG-Coupling caps, the bigger Power supply caps, and the little higher Voltage. I run "him" at 54Volt (Jumper on 220V instead of 240V, we have 230V here).
    It runs 10seconds after turning off...

    A bigger one from the other side:
    [​IMG]

    I bought the Nichicon KGs a few months ago to restore a Trio 60BE, They fit in perfect at the Au-222.
    Sorry, no more Off Topics.

    Greets Rainer
     
    Last edited: Nov 19, 2017
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  16. stereofun

    stereofun Super Member

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    That AU-222 resto is simply beautiful. There is something about the saying - "Less is more" - at least less electronics for the signal to get lost in ;-) A bit surprised the 999 and 222 sounded identical. The 999 being DC coupled, I can always hear the difference to my 777a, 555/505 cap couplers that has a more tube like presentation, especially a lower damping factor for bit blooming in the bass department. Please post more comparisons to your other gear, it is so interesting how amps have flavors almost like wine and how we like or dislike the sound. Of course rig synergy has a huge impact and is likely why we perceive differently and have, over the years, assembled our components to meet that ideal.... I cant have aggressive tweeters, but likes a fast mid bass and so forth....

    As for the 999, it is really important to get the current balanced through the diff. pair. Sansui didn't really address that importance, but just relied on 10% resistors. In the contemporary Eight, this was addressed by adjustments pots and in the successor the Eight Deluxe, some transistor balance scheme was employed to keep the currents in check. Aside from matching hfe on the diff. pairs TR801/803 and emplying 1% emitter resistors to those (R811/813) You can also, courtesy of Kevzep, address the R807/809 - R807 with a 1% resistor and R809 with a trimmer, thus making the balance adjustment real time and more precise than swapping resistors.
     
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  17. RS65

    RS65 New Member

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    Hello Tom,.

    i agree ro that. The rebuilding wasn´t very much work. Just one mainboard to take out, and the front is easy to unmount. It took 3-4 hours.

    My friend´s 999 was one of his first old Sansuis he had, and it sounded not good, after recapping it was better but not really nice. It had problems, sometimes one channel blows the fuse and it was difficult to find. A few weeks ago my friend found a bad transistor in the diffential pair of the main Amp. After fixing that the 999 is fine now. We also wonder about the same sound, because of the much different amps, DC coupled 222 and the massive direct driven 999.
    I could not discribe it good in english, but we think when the sound gets perfect, there are less differences in the sound. Without our AMP-Switch it was not possible to find out the differences just because of the different loudness of hearing.
    The AU-222 has less stages and really enough power, the 999 is more powerfull when it was very loud, to loud to hear. His 777 (wihout a) has less higher tone and not more bass than my 222.
    He has a Kenwood TK140 (without X), totally repaired with nearly all of the transistors changed (incl. the power ones), recapped and biased, that also sounds nearly perfect.
    I think, if the really good old amps are running perfect, there are very very little differences in real hifi, the amps had to be good, because of the lousy speakers in the sixties.
    Greets Rainer
     
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  18. smurfer77

    smurfer77 AK Subscriber Subscriber

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    Yup, i will do all the mods, one by one (although I may hold off the bass/EQ mod to the last, as I will do A/B with tone on defeat I think). But alas, I was thinking I was ready to listen to the stock AU-999 after fixing the driver board that was playing up, but just now I noticed the preamp is only providing about 3dB gain which can't be right (and clipping too early), and I see a bit of DC on the signal path between the filter board and tone boards.... so I will have to look into it before doing some proper listening to the stock unit before mods. I do often wonder, how many 'working perfectly' units are out there being listened to in a faulty state....
     
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  19. Multimode

    Multimode Member

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    I listened to a faulty AU-919 for 37 years before Hyperion discovered and corrected a couple of original build errors. No, I don't mean it took him that long to find them! ;)
     
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  20. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    Ha! :rflmao:
     
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