Sony TA-2650 recap with pics

Discussion in 'Solid State' started by leesonic, Jun 4, 2013.

  1. leesonic

    leesonic Hold on, here comes the bass. Subscriber

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    Here are some pictures of my Sony TA-2650 recap project. I've always liked these amps, the brushed aluminium faceplate just looks SO classy. The little 2650 gets no respect, compared to the VFET models, and it probably also gets overlooked because it's narrower than the 3650. But it's rated at 43 wpc into 8 ohms, has two tape inputs (including useful jacks on the front you can connect an MP3 player two), as well as an interesting "presence" control in addition to the usual loudness.

    [​IMG]

    Here is a view inside. Notice, there are a LOT of low-leakage orange Elna capacitors in here, more than I've seen in a lot of other amps. Notice as well the dual caps in one can in the power supply. The front and rear panels tilt to make servicing easier, but you still have to remove the boards to get to the solder side.

    [​IMG]

    Close-ups of the power amp board...

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    ...and the control amp and function switch board. Just look at that Alps volume control.

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    I carefully desoldered the volume control pot so I could open it up for cleaning. Here's a little photo montage of it.

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    Control board recapped.

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    Function board recapped.

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    These two smaller caps are going to replace this one big one.

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    Power amp board recapped.

    [​IMG]

    Lee.
     
    Renata likes this.
  2. BmWr75

    BmWr75 Addicted Member

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    Nice work!!
     
  3. Alienz

    Alienz Super Member

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    Great job! Thanks for posting this, i wondered how one could replace the big double PS cap, now i know how it can be done
     
  4. elicanis

    elicanis Active Member

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    Vancouver
    Thanks for the pictures.

    I would love to come across one of those Sony integrated amps.

    I am assuming it is from the same time period as the STR V series - the volume and function knobs share some commonality.

    I really like the inputs on the front - ss you said very useful.

    Looks great - way to go.
     
  5. electrohifi

    electrohifi Active Member

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    Ontario Canada
    Wow what a nice little amp to work on, very simple and laid out well. looks very well designed and I am sure you have noticed a nice improvement. Take your fine job to the next level now, change all the carbon film resistors on the preamp board to takman carbon films.....very, very, very nice resistors with tight tollerance and hold the sweet carbon tone qualities, yes we diyers finally have audiophile quality carbon films at a very attractive price, quite cheap actually.
     
  6. leesonic

    leesonic Hold on, here comes the bass. Subscriber

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    The Sony is good in this respect, since there is a big ground plane in the copper underneath. In addition, the dual cap has five terminals, and the two that have no connection were connected to ground. This meant that one cap could be soldered in using the existing holes, the other I had to drill an extra hole in the board and scrape off some solder resist.

    I thought about this, but using the same 1% metal film resistors I used for my NAD 3020.

    Lee.
     
  7. leesonic

    leesonic Hold on, here comes the bass. Subscriber

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    A picture is worth a thousand words, so here is one of the power amp board with the big dual cap removed, you can see the hole pattern in the board.

    [​IMG]

    There was a flat, rectangular washer sandwiched between the transistor and the heatsink, so there was twice the amount of silicone grease to dry out. I replaced this and the mica washer with more modern greaseless insulators. This is a kind of "before and after" shot, with the originals on the left.

    [​IMG]

    Lee.
     
  8. SoundOfSound

    SoundOfSound Super Member

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    What brand are they and where do you get them? :scratch2:
     
  9. Artie

    Artie AK Subscriber Subscriber

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    I couldn't have said it better. I have one of these sitting on my bench, waiting for it's "refurb". Thanks for the pics and the "nudge".

    Killer little amps. This, and my Yammy CA-400, are two of my favorites. :thmbsp:
     
  10. leesonic

    leesonic Hold on, here comes the bass. Subscriber

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    I figured it would make more sense posting my workings out for the LED series resistor here, rather than on a scrap of paper.

    Power amp rails = +-40 VDC
    Preamp rails = +-22 VDC
    LED voltage drop = 3.2 V
    LED current = 20 mA

    Resistor using power amp rail = 2.2k 2w or more (huge loss here)

    Resistor using preamp rail = 1k 1w (better)

    Lee.
     
  11. cristi68p

    cristi68p cristi68p

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    Location:
    Romania
    Final transistor changed

    Hello,

    I want to follow this post in order to recap my Sony TA 2650,but when I remove the cover to clean it up,I observe that the final transistors in my unit were changed.So what I have on the cooler are:
    - 2SA808A (Sanken)
    - 2SC1619A (Sanken)
    Also I observe that I have a lot of power when try to rise the volume pot.At 2 units,the volume is very loud,and is is already enough for my room.
    Do you think that is good?Should I change the final transistors to original ones?
    And if originals are not anymore into electric parts store,which are the best replaceble ones (equivalent)?

    Regards,
     
  12. leesonic

    leesonic Hold on, here comes the bass. Subscriber

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    Hmmmm... something doesn't sound right with your volume control. Before I started working on mine, the controls were all very scratchy, and sometimes moving the volume, or the loudness/presence control would make the sound come through really loud. I would recommend you clean all the controls with DeOxit.

    As for your output transistors, if the amp works now, why change them? Chances are you won't be able to find the original 2SD532 and 2SB518 ones anyway. I was looking at another thread, it seems that MJ15015 and MJ15016 can be used to replace these.

    Lee.
     
  13. cristi68p

    cristi68p cristi68p

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    Location:
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    Leakage?

    The unit sounds good,but I will try to change final transistors as long as I plan to recap it.I will use Elna Silmic II capcacitors.It will be my first recapping project,so this post will help me a lot !!
    Anyway,the phono input does"n work well.One channel has lower volume and when I look better,I observe some king of leakage on some electrolitics.I think is leakage, although this stuff is a hard one ( see no reason that stuff is used to fix better the caps on chassis).
    And details about final transistors:
    Hope that replacement what Lee says are the proper ones.
     

    Attached Files:

  14. cristi68p

    cristi68p cristi68p

    Messages:
    58
    Location:
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    Recapped with Elna Silmic II but BIAS high

    So,my first recapping project finished.It takes 5 hours for all boards and the unit is working very well.I used Elna Silmic II for all caps except the two 1000MF from phono preamp where I used Nichikon,Now the phono preamp is working and I am happy!!Overall,the sound quality is improved,but my impression is that is increased with only 10-15%.....maybe my ears are not so good....
    Here a few pictures,before-after.
    I detect some caps with different value as in SM - in Function switch board (22MF instead of 100MF,1 MF instead of 4,7MF) and Control amp board(47MF instead of 33MF) but I followed the SM and no problem detected.
    Now I am concern about the BIAS value.In the SM the value must be 0,025V but I read 0,37 V on my multimeter !!The trimmer pot is turned counterclockwise at it"s max position.Turning clockwise,the voltage increase.Strange that the sound is good,no distorsions and no heat dissipation from final transistors.Why?Are the trimmer pots bad?
     

    Attached Files:

  15. dimanag

    dimanag Active Member

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    112
    This thread was opened by Leesonic and he showed us his greate work on a sony amp. I am sure lot of us will appreciate his efort and will learn something new from here! If you have the same amp but with some problems and need help please open your own thread and asc for help there!


    Cheers
     

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