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110v sansui units.... Sansui au 9500.... What PSU is in your use??? 50 /60hz???

Discussion in 'Exclusively Sansui' started by quadklipsh, Jan 11, 2018.

  1. quadklipsh

    quadklipsh Super Member

    Messages:
    1,292
    Location:
    Lahore, Pakistan
    Hi guys...
    Iv wondered why in my homeland, electronics that run at 220v are more respected than 100/110v gear.
    My native supply is 220.
    Mostly when we buy a 110v imported gear, we already have a large stepdown transformer for it but even then 220v yet lower quality amplifiers would sell readily....


    2ndly, my Sansui AU 9500 didnot perform sweet enough as was expected when we auditioned a pair of mission 752 speakers with it.....

    I was thinking if my 16lbs robust 110v transformer is to blame here.....
    Is 50 hz or 60 hz rating of the transformer playing a role here..... In sound quality....
    Any views would be welcome
     

     

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  2. quadklipsh

    quadklipsh Super Member

    Messages:
    1,292
    Location:
    Lahore, Pakistan
    My stepdown transformer should be delivering 5 amps easily, i have never been able to measure that but from its size i can guess.
    Also its got voltage selector option between 90v to 126v.
    The sansui 9500 requires 205 watts and 550 VA... At 100v.
     
  3. tnsilver

    tnsilver AK Subscriber Subscriber

    Messages:
    2,999
    Location:
    Boston
    Because stepdown transformers for US made or US designated power hungry amps in 220/230V grid countries tend to be massive and expensive and need to be well built. When you make a compromise and get cheaper transformers, they tend to overheat and then convert excess energy to mechanical energy. This means their core starts rattling and humming and they are basically on the path to disintegration. This process is faster in hot climate countries. No one likes humming and rattling in their stereo. Adding insult to injury, most of the big massive > 1KVA transformers are not grounded to mains. This could lead to an extra humming issue, especially when adding a turntable to the system. Most amps don't care about the power grid frequency so the 60Hz specs won't matter - but many AC synchronous motor turntables do and are a PITA to convert. In the era of cheap mass produced electronics appliances, obtaining a high quality solid and robust high power stepdown transformer could prove adventurous in some places. I guess the people in your homeland know exactly what's good for them. It is not really surprising favoring 220V gear in a 220V grid country.

    EDIT: I was on a relocation for a few years in some 220V countries and some included solid communities of US made hi-fi gear fans. It was common practice to use stepdown transformers that were rated at least twice the amp's consumption power to make sure those Krell, Crowns and Mc's are never deprived of input wattage. Honestly, 16lbs of a 110V stepdown transformer isn't that impressive and I would suspect it's underpowered. We had a Topaz transformer that size for our GE refrigerator and the transformer literally killed it self overheating in less than two years. The transformer in a 9090DB unit (multi-voltage), for comparison, is at least 25 pounds. Besides that, Sansui fans tend to respect Sansui's bullet proof built in transformers. That company started out making transformers so I can understand how adding a stepdown of unknown quality on top, is kinda undesired. Finally, I'm not sure what you mean by "not sweet enough" but this could be a separate issue having nothing to do with power consumption / supply at all. Maybe the missions aren't a good match for the Sui', maybe the Sui' needs some TLC and a recap, maybe it's all, or just part, of the above.
     
    Last edited: Jan 11, 2018
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  4. quadklipsh

    quadklipsh Super Member

    Messages:
    1,292
    Location:
    Lahore, Pakistan
    Tnsilver,
    Thanks for the responce.
    It surely has to be the mission sansui combo. The sansui was totally recapped and performed beautifully with AR and infinity speakers. My tech informed me that this amp surpassed his expectations in sonics as well as design/engineering aspects. He had a poor opinion of the sansuis previously but after he checked out the 9500 with his AR and infinity 155, the sansui 9500 bacame a favourite one. He also owns a kenwood supreme 600 which is his top amplifier.... I also sent him an AU 517 which made another favourite. But 9500 was 2nd only to 600.

    Anyhow...
    I had klipsch RF3s previously and the amp played beautifully with them too....

    Hence i believe the amp prefers a high sensitivity speaker and one with a slightly forward top end.
    It has a very gentle laid back sonic character and prefers brighter than neutral speakers and the mission 752s are surely very laid back ones....and not a match with this sansui.

    As for the stepdown trafo... i have 3 of them. Two have the size almost bigger than the transformer inside the 9500 which is to say that i may have a wrong guess of their weight (16lbs).
    They run slightly warm and never look strained. But id surely want to look further into the supply voltages...
    One more thing...
    As the amps voltage requirements are 100v or 117v, does it matter if i keep it around 110v
     
  5. RobinTW

    RobinTW Member

    Messages:
    59
    Location:
    Taipei, Taiwan
    What type of transformers are you using? For amplifiers and other audio equipments, you need to use isolation transformers for best sonic performance. Also, toroidal transformers are recommended.

    I have a 1000W, 110V to 100V stepdown toroidal transformer. The toroidal itself weights about 9Kg.
     
  6. Hyperion

    Hyperion Roobarb & Custard Subscriber

    Messages:
    48,611
    Location:
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    The whole point of a stepdown transformer is that it provides the correct voltage, the line frequency difference might result in a slightly warmer transformer - the one inside the gear, not the 'step down'. The slightly higher voltage you are using probably isn't anything to do with your sound quality dissatisfaction, but for a 100V rated piece, you should use a 220V (for your local mains voltage & frequency) to 100V step down transformer. The power rating of the transformer should be as generous as possible otherwise you could experience issues with the connected HiFi equipment. I have a 240V --> 100V step down transformer for my Sansui AU-X1 - the amplifier is rated at 160Wpc - the step down is rated at 2kW I think.
     
    Last edited: Jan 12, 2018
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  7. Overundr1

    Overundr1 AK Subscriber Subscriber

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    A 2KW step down transformer must have some serious iron inside. On the other hand in rural Mississippi we have a different challenge with voltage fluctuations both up and down as well as line noise due to all the farmers and their electric cattle fences.
     
  8. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    Ah - correction - it's 1.5kW actually ;)

    That's a difficult situation Lee, with an expensive solution I think - Iron and Copper only isn't going to completely fix that - pure sine wave voltage stabilisers are not cheap. :)

    I am so lucky - our mains voltage varies from around 230V - 245V - but those are unusual extremes - mostly around 238V - with, as far as I can make out, very little noise on the line. :)
     
    Last edited: Jan 12, 2018
  9. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

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    Hyperion; It probably wasn't made with Lucas parts then. :music:
     
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  10. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    Well, I know you guys aren't too keen on Lucas parts, but there was a time certainly in the UK, when Lucas Automotive Parts were one of the very best. :)

    I assume that's what you are alluding to?
     
    Last edited: Jan 13, 2018
  11. kevzep

    kevzep Its all about the Music Subscriber

    If the unit is 120V only, it will have a smaller transformer than an export model which has multiple primary windings. Its not to house the extra windings, its to do with the core size and the frequency its designed to run at.
    A 50hz transformer needs to be bigger than the same transformer designed for 60hz.

    Using a stepdown transformer does not get around the fact that the transformer you are stepping the voltage down for, is designed for a different frequency, a 60hz transformer will run warmer on 50hz, some say its not a good thing, but I've never encountered any issues doing this before.
     

     

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  12. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
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    Obviously they never made it across the pond. I had a '71 MGB back around '75-'78. 12-18 hours before a low front would come thru it would start sputtering, the electrical gremlins got fed after 9p.m., and they all had bath's(this is Md. we're talking about)and the harness would act up, one time catching fire. replaced the harness. A high pressure system would come thru with cloudless sky's, and it would run like the proverbial Swiss watch. RAIN?? Forget it. Could never get the SOB started. Turns out that the Distributor itself had a hairline crack in it and the HI-VOLTAGE would go to earth thru the leakage path when damp or wet. After replacing the distributer, about 4 months afterward the cap cracked. I traded it in on an 80 Pontiac Sunbird (Chevy Monza in disquise).
     
  13. Overundr1

    Overundr1 AK Subscriber Subscriber

    Messages:
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    Location:
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    Nothing wrong with Lucas electrics that a time out for tea won't magically make right again :)
     
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  14. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    Being so partial to a nice cup of tea over here, perhaps that's why we never noticed. :)
     
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