Sony TA-5650

Sony's V-FET best-seller.

And the only V-FET amp holding one little unknown gem, too : 2SK63, small-size V-FET for low-power applications. The 2SK63 was used in the phono stage of the TA-5650 and nowhere else.

Since the TA-5650 was released last among Sony's 1st gen' V-FET amplifiers, this addition makes sense but Sony's discretion about it still seems a little... typical Sony !

As all of Sony's 1st gen' V-FET units, the diodes and some resistors MUST be changed otherwise they'll take the amp section away and quite rapidly.

Said diodes are the reason why many TA-5650 died all too quickly in the 1970s and 1980s : the V-FETs had nothing to do with it.
The same sad fate happened to many a TA-N88B ; the V-FETs again had strictly nothing to do with the failure(s). Why Sony didn't communicate on this is, again, typical Sony :)

Also, as all 1st generation Sony V-FET, do NOT use a variac when powering the amplifier for the first time !

Thanks to Mark (of vintagetechnics.com) both the 1976 Service and Owner's Manual are available in pristine quality on request from TVK.
Mark does "still view it (despite my Technics obsession) as the ultimate integrated amp."

The TA-5650 was briefly available as a Wega V-4810 : black-face with clearer sideburns. Very rare.

• SONY TA-5650                             (4)last updated by virushaus - 02/11/2010, 18H59 Open this topic in TVK Talk
  • #1
    
    virushaus
    23/09/10
    14H30
    Hello,
    
    I recently bought that amp and here on TVK I read that there are some tweaks/fixes to be made to use this amp on a daily basis without any problems.
    Can someone tell me what exactly needs to be done ?
    
    Thank you in advance for your help.
    
    Best regards,
    Jakub
    
    EDIT
    thread moved to the V-FET section.http://www.thevintageknob.org/tvk_talk/viewtopic.php?f=1484&t=309.
  • #2
    
    Socal Sam
    17/10/10
    05H54
    Yes, I recall the same advice for the TA-5650. IIRC, it had to do with the recapping the power supply and replacing the bias diodes. While you are inside, you might as well recap the amp boards.
  • #3
    
    Axel
    17/10/10
    12H10
    The mods, tweaks and safety moves for all V-FETs will land in the upcoming (Knobber-only) EE section - they are currently being compiled, checked, verified and augmented.
    This will at first cover the most common first generation of the Sony V-FETs : TA-5650, TA-4650 and TAN-5550.
    
    As for when... patience is a virtue ;-)
  • #4
    
    virushaus
    02/11/10
    18H59
    I thought that some of you might find it quite handy:
    
    SONY TA-5650 - V-FET REPLACEMENT datasheet
    
    http://www.alldatasheet.com/datasheet-pdf/pdf/149574/SONY/TA-5650.html