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Fisher sa16 advice (my first tube amp}

Discussion in 'Fisher' started by PK Vintage, May 28, 2018.

  1. PK Vintage

    PK Vintage Active Member

    Messages:
    122
    Hello all
    I just purchased my first tube amp. It's as the title says a Fisher sa16 in perfect working order....... I think... as I'm not really sure just how good it is supposed to sound. I am used to solid state active systems the likes of Linn, Meridian,Revox with Bryston. pretty good stuff.

    I like to have my gear as good as it can possibly be within reason of course I don't chase that final 5%. So I'm looking for some advice on some upgrades. I have read through the threads and seen a few things but I just thought I would start my own thread.

    I'm going to take it apart and completely restore the chassis. The Sprague vitamin Q caps seem to be a pretty good capacitor for tubes but are they the right capacitor for this amp?
    Of course all the tubes will be tested. My tech friend has been working professionally on tube gear for 25 years so he'll be doing all the work.
    I look forward to your comments and suggestions

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  2. PK Vintage

    PK Vintage Active Member

    Messages:
    122
    I noticed the level adjustments have been removed and replaced with new RCA inputs. I would like to put this back to original. Can I buy those adjusters anywhere?
     
  3. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
    21,887
    Location:
    Glen Burnie Md.
    Get the Service Manual for the 1960 Coronet 808. It'll have the parts list and schematic for the SA-16. The pots you're looking for are 500K pots. Whether they are Log or linear I couldn't tell you. You might PM Dave Gilliespie and ask him. Part #'s R1 & R3. AES may have the small factor form pots in that size.
    Manual here.........http://www.fisherconsoles.com/coronet c808.html Then click on Service manual at the top of page.
     
  4. heyraz

    heyraz AK Subscriber Subscriber

    Messages:
    1,924
    Location:
    Long Branch, NJ
    The amp looks good to go. Nice work.
    The original RCA inputs were spaced closer together back in the day. You'll have trouble getting modern cables to fit next to each other given the close spacing.
    I think that's why the level controls were replaced with new inputs.
    Underneath...I'd put a little distance between the big blue capacitor and the power resistor (hot). It'll last longer that way.
     
  5. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
    21,887
    Location:
    Glen Burnie Md.
    I mentioned this on the thread in the tube forum. Keep an eye on those "brass" spkr connectors. They have a tendency to go "SOFT" and bend, possibly shorting on the chassis. If it were mine, I'd go back to spade connectors, solder the wire to them and cover with heatshrink.
     
  6. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    36,973
    Location:
    Southern NJ
    Probably log pots.

    Honestly I'd probably leave the RCA jacks as they are. Unless you really see yourself adjusting those level pots, a simple resistor in place of the pots is going to be less noisy and more reliable long term.

    Another speaker terminal option are those Pomona screw to banana adapters. Part number is in the sticky somewhere.
     

     

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  7. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
    21,887
    Location:
    Glen Burnie Md.
  8. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

    Messages:
    9,764
    Location:
    Ball Ground, GA
    Pots that function as "level" pots -- as is the case with the SA-16 here -- are always linear pots, this because they are meant to be adjusted, and then left alone. Volume controls on the other hand will always be log pots, so that the control responds more closely with the way the ear reacts to various sound levels.

    Dave
     
  9. heyraz

    heyraz AK Subscriber Subscriber

    Messages:
    1,924
    Location:
    Long Branch, NJ
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    I tried those brass banana adaptors. They put too much stress on the terminal strips and would have most certainly torn them apart over time.
    My solution may be inelegant, but it's functional and places no stress on the original terminal strips.
    It also makes swapping amps a snap.
     
    vaathi likes this.
  10. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

    Messages:
    9,764
    Location:
    Ball Ground, GA
    I like your adapters Hey! I do something similar using 1/4" mono phone plugs. Exactly as you say, makes changing speaker connections between amps a snap, and doesn't damage the terminals over time.

    Dave
     
  11. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    36,973
    Location:
    Southern NJ
    My only comment on the adapters is to make sure you support them so they aren't still hanging off the screws. I honestly like that better than the Pomona deals because it lets you use standard spacing dual banana plugs. Honestly the input and output connections on old gear are one of the things I truly do not love about them.
     

     

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  12. heyraz

    heyraz AK Subscriber Subscriber

    Messages:
    1,924
    Location:
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    All of the stress is close to the base of the terminal and there's not enough weight from the plugs and adapters to be an issue.
    Those brass extensions are another matter, the weight is far away from the base so leverage becomes an issue.
     
  13. PK Vintage

    PK Vintage Active Member

    Messages:
    122
    Those adapters have received quite a bit of attention. As I mentioned earlier mine have bare wire screw downs that I use so there is no more tention than soldered wire with terminals. I move gear around alot and don't keep banana on all wires. Banana plugs inserted on the other hand would cause tention especially with heavier wires.
     
  14. heyraz

    heyraz AK Subscriber Subscriber

    Messages:
    1,924
    Location:
    Long Branch, NJ
    I tried the same adapters that I see on your amp (brass forks).
    The forks were too wide and the adapters didn't sit stable. The best I could do was to pinch the forks together, but it still wasn't great. Now I have a half dozen or so in my parts bin.
    The terminals I used on my amps are rings, not forks. They're in for good and stable. 15276327173171329762813.jpg 15276328240442009788886.jpg
     
  15. thornev

    thornev Well-Known Member

    Messages:
    557
    Location:
    Mid Hudson Valley, NY
    Raz... Did you buy those or make them? If bought, where? I have the same situation: 2 receivers with the same, different speaker ports.
     
  16. heyraz

    heyraz AK Subscriber Subscriber

    Messages:
    1,924
    Location:
    Long Branch, NJ
    I think I've made 5 of them so far.
    I got the bakelite boxes and 5 way dual binding posts from either Radio Shack or Parts Express.
     

     

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  17. kevco

    kevco Member

    Messages:
    93
    I have used the L shaped brass adapters on my SA-16 for years and have never had an issue. They hold firm, don't sag and to my ear are acoustically transparent. I also hack sawed a pair to fit cleanly on a Bogen AP-30 integrated amp with great success. I wouldn't worry too much about them as long as you're not hanging enormous speaker wire on them. Nice amp by the way, the SA-16 doesn't get much love but with some decent coupling caps and a plate current matched quad of 7189's you can't do much better in the 15 watt range. Yours looks to be good to go minus perhaps a chassis clean up. Enjoy it!
     

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