Sony STR 4800SD

Discussion in 'Solid State' started by sqelio, Oct 26, 2007.

  1. sqelio

    sqelio New Member

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    Ran across a Sony STR 4800SD at an antique shop. Receiver is in good shape cosmetically. Does anyone have any specs or any type of info? Not much on the web.
     

     

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  2. bully

    bully member

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    Orion sez 1977-82, 35 wpc. Should be a nice little piece.
     
  3. Aldo

    Aldo Show me the silver!!

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    I have one of those, it is a nice unit, and physically much larger than you would expect for 35wpc. The Dolby FM tuner section is one of the best I've heard....:thmbsp:
     
  4. reggaenaut

    reggaenaut Addicted Member

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    Has an excellent am section. I gave one to a friend and he was so pleased with it.
     
  5. gusten

    gusten Addicted Member

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    My wife has STR-2800 in her shop.(I gave it to her).She uses it for background music,and it really sounds very good at low volumes. It has worked perfectly since -78.
    I think 2800,3800 and 4800 are quite similar.
    /gusten
     
  6. Yamaha B-2

    Yamaha B-2 registered user

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    Here is the Sony sales brochure for the STR-4800.
     

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  7. RaymondLeggs

    RaymondLeggs Super Member

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    VU meters! :D
     
  8. HIFIVINYL15

    HIFIVINYL15 Active Member

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    VA
    I Just picked up one of these guys locally for 20 big ones, got it running through my Kenwood KL-333s, I've tried the FM tuner, which sounded wonderful, and I'm currently running my Realistic TR-882 8-track player through it. Sounds great, I think my run of bad luck with picking up these older receivers is over (Cap issues on both my free sherwood and sansui) :)
     
  9. Laserdude

    Laserdude No polar bears here...

    Messages:
    308
    Location:
    Denmark
    Country: Japan
    Manufacturer/Brand: Sony; Tokyo
    Year: 1976 Type: Radio - or past WW2 tuner
    Semiconductors (the count is only for transistors) Semiconductors present.
    Principle Super-Heterodyne (Super in general)
    Wave bands Broadcast (BC) and FM.
    Power type and voltage Alternating Current supply (AC) / 110; 120; 220; 240 Volt
    Loudspeaker - This model requires external speaker(s).
    from Radiomuseum.org Model: STR-4800
    Material Wooden case
    Shape Book-shelf unit.
    Dimensions (WHD) 490 x 170 x 400 mm / 19.3 x 6.7 x 15.7 inch
    Notes Stereo-Receiver: Phono, Aux, 2x Tape.
     
  10. Oilmaster

    Oilmaster Drillers go deeper Subscriber

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    If I'm not mistaken: these series have the integrated thick-chip STK output amplifier modules instead of discrete components due to the lack of space (and cost-wise at that time). The integrated STK modules have often the benefit that you have no DC offset and no bias idling current to set/check, they are self-adjusting inside the STK circuity. On the other hand, when the STK modules go sour, then all you can do is replace them, if you can find them. Sound-wise there's nothing wrong with STK modules, though not the same performance as a discrete stage, but don't stress them to the (thermal) limit without cleaning and replacing the compount between the STK chip and heat sink.
     
  11. HIFIVINYL15

    HIFIVINYL15 Active Member

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    What exactly do you need to replace between the chip and heat sink? Could you clarify? Also what are the symptoms of the STK going sour? Thanks!
     

     

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  12. Oilmaster

    Oilmaster Drillers go deeper Subscriber

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    As for most output devices, the STK modules are mounted to a heatsink to dissipate their heat. A thermal paste is put in between in order to increase the surface exchanging heat from device to heatsink (and therefore to obtain maximum heat transfer rate). The thermal paste is NOT there to conduct the heat from device to heatsink, as many folks think; the thermal paste is in fact an insulator, and shall therefore be kept as thin as possible.

    If the metallic backside of a device needs to be electrically isolated from the heatsink, then a mica washer, with or without thermal paste, is inserted in between the two (not often the case for the STK modules I think).

    An alternative that arrived on the market after these STR series is the SIL pad technology (combination of thermal paste and isolating function), but I haven't seen SIL pads for STK modules, only for regular transistors (TO-3, TO-220, etc). And it takes some knowledge to select to 'right' one as they come with different characteristics.

    The remark I made is to clean and replace the thermal paste because it dries out, becoming more and more a thermal insulator (and reduced heat transfer surface) and the STK module becomes ever warmer, degrading the integrity of STK module, eventually resulting in failure. Hence, stressing (high volume) a vintage STK-containing amp/receiver can be risky.

    PS: your avatar suggest this would be usefull for you....

    Symptoms of an STK going sour? Well, when the sounds start sounding s**t :D Meaning: too late :tears:
     
  13. Laserdude

    Laserdude No polar bears here...

    Messages:
    308
    Location:
    Denmark
    I Have a amp that did have a bad STK chip, the amp would work fine for a while and suddenly "bang" in one channel. Repairs cost me 282 Dollars, so it´s not cheap.
     
  14. dspear99ca

    dspear99ca Super Member

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    There are those who would disagree with the comment about performance (or lack thereof), the specs on some STK (and SVI) modules are quite excellent with sound quality to match. They have perfectly matched input differential transistors which virtually eliminates DC offset and the audio ramifications of same. They are prone to cooking if not properly heatsinked, google "blockslide". But then, discrete components dislike heat just as much... they're just cheaper to replace ;-)
     
  15. Oilmaster

    Oilmaster Drillers go deeper Subscriber

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    Well, we could (should?) start a new thread on that subject ! We could have interesting and profound discussions on that matter. However, to stick with the subject of this thread, I would say that Sonys of that era were built in quality, and I guess the (early) Sony STKs were not different from that building philosophy. Also, the surrounding power supply, tone control are what they should be (often completely reduced the poor circuitry in cheap 80's gear using the STK for economic reasons).

    Also the tuner part of this model is decent, and all together it makes up a very decent piece of vintage gear, which looks great too (I have a similar looking ST-5950SD tuner). A good reason to buy a matching amp (3650/4650/5650) and tape deck TC-209SD (the only deck with the same black switches). See example here.

    PS: ......eh no, let's not make a PS on STK vs. discrete..... :D

    EDIT, forget about the 'black switches, this STR model hasn't got them, though the TC-209SD is one of the rare Sony tapedecks with black VU-meters, matching much better with the black tuning meters of the ST/STR series of that era.
     
    Last edited: May 17, 2011
  16. Oilmaster

    Oilmaster Drillers go deeper Subscriber

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    $282 ? :sigh: What STK model was that ??
     

     

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  17. 68custom

    68custom Addicted Member

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    great receiver, almost bulletproof.
     
  18. Laserdude

    Laserdude No polar bears here...

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    Location:
    Denmark
    STK 3102III 2 x 115w 60v in a Philips FA960MKII amp from 1988. But things (and repairs) here in Denmark are usually more expensive than in USA.
     
  19. HIFIVINYL15

    HIFIVINYL15 Active Member

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    Pics :D

    Thorough cleaning and now she's all set to go, found a new 12V5W bulb for the signal strength/tuning lights and they glow nicely, seems as though the green tint on the tuner screen has faded where it is close to the light, interesting. A couple pots are bent but they turn smoothly. Also the volume pot needs to be turned sometimes so that both channels get equal volume, i'm sure i just need to keep spinning it until it's fully cleaned. Not bad for 20 bones and a little elbow grease :)
     

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  20. Oilmaster

    Oilmaster Drillers go deeper Subscriber

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    Sorry to tell you, but you can find them between $7.50 and $15.00 on fleabay :smoke:
     

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