Sansui AU-101 - weird boom / high-pitched sound

Discussion in 'Audio Hardware' started by Ahsan, Nov 25, 2021 at 7:09 PM.

  1. Ahsan

    Ahsan New Member Thread Starter

    Dear All,

    I have just received my Sansui AU-101 today in really good cosmetic condition (well chuffed), and fired it up with Wharfedale Denton 80th Anniversary addition speakers (6 ohm suitable for 20w - 100w amps per manufacturers recommendation).

    However, with loudness turned on, if I turn the bass dial beyond 0 or turn the volume up beyond level 4, it creates that high-pitched sound as if when your mic is too closed to your speakers, like a loud boom in the room. Could someone help me out what could be the case, is it the speakers being too heavy or are we talking something wrong with the amp?

    With loudness on, it produces sweet warm sound till up to volume level 4, and with loudness off, I can turn it up more. With loudness on, if I turn the bass all the way to + same boom / high-pitched noise starts again.

    Many thanks in advance for your help.
     
  2. AL01

    AL01 Eh?

    Location:
    Texas
    I can't tell you what is wrong, but all I can say is that something is up with your amp and it is most likely needs some work/servicing.

    If you bought it on the 'Bay, you may want to discuss with the amp's seller about a return/ partial refund.

    (If you like the amp, get it serviced, but you don't want to spend too much out of your pocket, especially if the amp was sold to you as 'fully' working..)

    My apologies if this is not of much help, but this is what I would do if I were in your situation.
     
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  3. Thorensman

    Thorensman Forum Resident

    Loudness controls do give a large boost.
    You may exprience feedback.
     
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  4. Ahsan

    Ahsan New Member Thread Starter


    Thanks mate, I should certainly discuss with the seller (it was ebay) - I only received it today so wanted to double check before I jump the gun. It does have some crackling on let's say on / off button but that is to be expected from a 40 year old amp - but this is a completely different issue you are right. I certainly have paid top price so having it recapped isn't on the plan right now.
     
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  5. Ahsan

    Ahsan New Member Thread Starter

    Hi mate, is that normal? I have no reference so just don't know if that's normal - the feedback is quite loud and stays there.

    Thanks so much for your help.

    BTW - I have just been reading, on other forums and users are saying that loudness control usually is intended for lower volumes. I just wonder if that's normal to have the feedback!
     
    Last edited: Nov 25, 2021 at 8:01 PM
  6. AL01

    AL01 Eh?

    Location:
    Texas
    It ain't working, so you outta jump the gun on that fella.

    My opinion on vintage is to either buy it cheap (if unrestored) or buy something that is completely restored, (not mere deoxit and a bias.) I bought a serviced AU-517 (Deoxit and some caps) and got a solid 4 months out of it. A risk is a risk, you may get lucky, or end up losing money.
     
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  7. Ahsan

    Ahsan New Member Thread Starter

    True, this was listed in working condition so definitely need a word. I might be learning the hard way here, although it wasn't overly expensive I am a newbie and would probably struggle to recap / fix stuff myself so vintage is always going to be risky unless I get it super cheap and restore it etc. which won't happen :D
     
  8. namlook

    namlook Forum Resident

    Location:
    Canada
    This guy doesn't know what he's talking about.
     
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  9. Gordon Crisp

    Gordon Crisp Forum Resident

    Location:
    Portland, Oregon
    Maybe try disconnecting/re-terminating your speaker cables and interconnects?
     
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  10. Lenny99

    Lenny99 The truth sets you free.

    Location:
    Clarksburg WV

    Yes: I think this is a great idea.

    There could be many reasons for this issue that are beyond me. So, I think this is a good idea. Check some easy fixes, like disconnecting and reconnecting the speaker cables. I wouldn't touch the component.

    Could it be a problem of compatibility between a vintage component and the OP's newer components?

    If I was the OP, before I'd send it back I'd make sure it was nothing on my end. Then, perhaps contact the seller and explain the issue, tell him or her what's up.

    Good luck
     
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  11. Ahsan

    Ahsan New Member Thread Starter

    Thanks Lenny99, Gordon,

    Very helpful. I am going to exactly try those things - I have ordered some decent wires and also 3.5mm to RCA to try other digital sources. I posted on another forum yesterday and in addition to the positioning of speakers, someone mentioned that the feedback could be my turntable acting up as a mic pickup. This was an interesting point and then I started googling and it might have some legs. So, keen to also test out another source.

    Thanks again and I shall report back.
     
  12. Classicrock

    Classicrock Forum Resident

    Location:
    South West, UK.
    Working condition can mean anything. Seller probably thinks it's OK if it fired up. It is worth fixing provided you didn't pay a lot. Also I would fit modern speaker terminals. I owned one around 1973/4 and new it was a lovely sounding amp. More powerful than 15W suggests.
     
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  13. AL01

    AL01 Eh?

    Location:
    Texas
    Doncha' worry, I am a newbie too.

    Learn from my bad decisions...

    I (as of now) lost almost 500$ because I was trying to be cheap instead of doing things the right way.

    Maybe I will make some it back when I sell my 517, but still...
     
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  14. Lenny99

    Lenny99 The truth sets you free.

    Location:
    Clarksburg WV

    Yes to the thought of feedback.

    I believe that depends on the position of ur speakers(s) to ur TT. I think it occurs when one speaker is in back of the TT, or too close to the TT.

    That happened to me a while back. It did produce a rumbling distorted sound. I think it was prevailent at mid to high volumes.
     
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  15. John Buchanan

    John Buchanan I'm just a headphone kind of fellow. Mysphere 3.2.

    He actually does know what he’s talking about, particularly if the OP is using a turntable.
     
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  16. bluesky

    bluesky Forum Resident

    Location:
    south florida, usa
    Over at Audiokarma Forum (AK - a different site) there is a Sansui Forum. The guys there know everything Sansui.

    Many 'highly qualified techs who can tell you exactly what your problem is. :righton:
     
    Last edited: Nov 27, 2021 at 7:21 PM
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  17. Ahsan

    Ahsan New Member Thread Starter


    Hi Lenny99,

    You are spot on, my speakers were I'd say around 1 to 1.5 metres behind the turntable, and then the turntable was in between speakers and the amp - impromptu set up! Just an update, I received my 3.5mm to RCA cable today and tried it out in a different room - hooked my iPad in aux and then CD input. No issues at all. Tested out with / without loudness and worked perfectly.

    Starting to enjoy that warm sound - much different to what I am used to (usually just listening on phone / and lately my old samsung 5.1 AV, which is really good with panasonic speakers) - guess that's just digitally enhanced / cleaner music.

    I opened the hood and it's all been cleaned but doesn't look like anything has been changed internally - very happy all in all for a £100.
     
    AL01 likes this.
  18. Ahsan

    Ahsan New Member Thread Starter


    thanks buddy, I think he also gave it a thorough clean - been testing it out with my ipad through aux / cd inputs and its been fine. Opened the top cover and it looks in a pretty neat shape. I really like the idea of fitting modern speaker terminals - I shall look into it. A friend of mine is an electronics engineer and has his own workshop up here so I can always pick his brains up and use his tools he he.
     
  19. Ahsan

    Ahsan New Member Thread Starter

    Thanks mate, I posted at audiokarma, and diyaudio - folk at diy audio were really helpful and engaging as well.
     
  20. Ahsan

    Ahsan New Member Thread Starter

    ha ha, I feel a little better! I wanted to go full budget but ended up buying used but good equipment, and have been lucky s far with my purchases. My turntable is Pro-Ject Debut Carbon Esprit (only gripe is that guy taped the plate and arm and it ended up being full of residue - still haven't been able to clean it off the acrylic plate - googled and wd40 might be the answer without ruining the thing). Then I picked up pro ject phono box s and headphone amp locally, loved those - sold the headphone amp as I thought I'd never use it (I was wrong though) - should have kept it.

    Then I picked up Denton 80th Anniversary at an amazing price from an hour's drive from where I am - the guy was an audiophile and got a chance to look at his set up which was amazing. I was going to get a new amp (yamaha / marantz) but ended up picking this one up :D

    So far, I am just around £600 with everything.

    Got my eyes on Yamaha WXA 50 - which'd be an amp and a streamer - plenty of juice for my room and I can use it as a streamer too. They are just going for quite a bit of money though!

    Story of my life :D
     
    Last edited: Nov 27, 2021 at 7:41 PM
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  21. AL01

    AL01 Eh?

    Location:
    Texas
    Don't use WD-40; try Goo-Gone instead as it is safer on plastics, (though acrylic is very resilient.)

    I'm happy to hear that the issue was simple.

    :D
     
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  22. Classicrock

    Classicrock Forum Resident

    Location:
    South West, UK.
    For tape glue try AF Labelclean or lighter fluid. WD40 contains silicone so maybe not a good idea. Have you compared the inbuilt phono stage on the Au101 to the Phono Box? It could be as good or better. Remember it sounding fine with a Shure M75 at the time.
     
    Last edited: Nov 28, 2021 at 4:40 AM
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  23. AL01

    AL01 Eh?

    Location:
    Texas
    Usually the 60-100ish dollar phono preamps sound better than many vintage internal preamps, (up to mid-range offerings.)
     
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  24. Ahsan

    Ahsan New Member Thread Starter

    Brilliant, thanks guys - I see if AF Labelclean / Goo-gone are available in the UK - I did some quick google search and came across a few suggestions to use wd40 as it's made of fish oil apparently? the residue on the platter is so strong that my felt Matt has stuck to it :D

    Re the phono, I personally found the external phono sounded much better in this case. The overall sound quality was miles better, I have Pro Ject Phono Box S. My first pre-amp was NAD PP 2 and it was actually my first ever turntable experience, kind of put me off but then I ended up buying this one and boom.
     
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