Sony VFET amps: is there a good technician in the UK?

Discussion in 'Solid State' started by MP984, Sep 12, 2017.

  1. MP984

    MP984 AK Subscriber Subscriber

    Messages:
    6
    Location:
    UK
    Hello. I'm fairly new to AK, but a while ago I bought a Sony TA-F7 VFET amplifier, which was restored by the previous owner (including a recap).

    I'm not a technical expert, but I gather that replacement VFETs are very difficult to find, so if one blows then it's probably curtains for the amp. From my reading on AK, this is less likely to happen if the other components in the amp are kept in good condition.

    At the moment the amp sounds great. However, for future reference does anyone know an expert technician in the UK who would be able to work on this amp? I would like to keep it serviced periodically.

    If the technician is based in the South East (I'm in Colchester) that would be even better, as it would avoid having to mail the amp.
     
  2. inductor

    inductor Super Member

    Messages:
    1,399
    Location:
    uk
    probably not then
     
  3. MP984

    MP984 AK Subscriber Subscriber

    Messages:
    6
    Location:
    UK
    Do you know someone elsewhere in the UK then? I can post the amp, I'll just have to be careful when packing it.
     
  4. slimecity

    slimecity Super Member

    Messages:
    1,556
    Location:
    New Zealand
    There are some components in these amps which need to be replaced (the "death diodes") if you do some research on what and where these parts are, you could probably do a visual check inside to see if these have been replaced.

    If you also keep checking the bias periodically yourself (If you are up to it, say annually or so) then it may not be necessary to keep periodically having the amp checked. A lot of these amps have been running for 20+ years without intervention and been doing OK.
     
  5. MP984

    MP984 AK Subscriber Subscriber

    Messages:
    6
    Location:
    UK
    I believe the 'suicide' diodes have been replaced. Unfortunately I have no idea how to check the bias.

    I take your point about not needing to have it looked at regularly. It would be good, though, to know of a good UK technician who is familiar with these amps, just in case anything goes wrong in the future.
     
  6. Chits

    Chits New Member

    Messages:
    6
    Don't let your amplifier control your life. If it gives you stress, chuck it. It's not that special, anyway. Ignore the online hype.
     
    slimecity likes this.
  7. slimecity

    slimecity Super Member

    Messages:
    1,556
    Location:
    New Zealand
    If you don't get any responses here - try over at DIY audio.com as well. There are a lot of VFET-heads on that site who may be able to help.
     
  8. MP984

    MP984 AK Subscriber Subscriber

    Messages:
    6
    Location:
    UK
    Excellent suggestion, thank you.
     
  9. Binkman

    Binkman Addicted Member

    Messages:
    5,967
    Location:
    Raleigh, NC
    Greetings;
    This amp is not a car. No fluid checks etc. tire balancing would probably better investment :D

    Only thing I'd be concerned with fet's is power outs and surges when it comes back on ground crap spikes.. so I'd get a good power strip and do proper shut downs and disconnect from wall if away? or expecting a big storm! Most pro's do that for computers to any power audio equipment or printers etc.
     
  10. DRecovery

    DRecovery Pants-wearer Subscriber

    Messages:
    925
    Location:
    Rochester, Vermont
    This is a (quite valuable) second-generation VFET amp, and not prone to outright spontaneous failure like the 1st gen amps.

    Since it's had a recent restoration, there is little else you can do for it except enjoy it.
     

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