Fisher 400 - Rebuilt but sounding muddy

Discussion in 'Fisher' started by healyc139, May 6, 2018.

  1. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
    21,440
    Location:
    Glen Burnie Md.
    I don't see anything wrong in the front end. Except the fact that the guy who rebuilt it loves those silver colored caps (vitQ? or K-40-Y?).

    Healy. If you can lift one side of one of the DALE's you can get the value with a meter. Then solder it back in. Or just try with the meter and the resistor connected. You'll probably get the rest of the circuit involved too but it's a shot.
     

     

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  2. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
    21,440
    Location:
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    Try moving your speakers away from corners and walls a little, say a foot or 3. Test again. Did wife change curtains, furniture in room, etc.
     
  3. healyc139

    healyc139 New Member

    Messages:
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    Location:
    Chicago, Illinois
    I'll try speaker placement also, but nothing changed from a surroundings standpoint. The receiver really sounded amazing for a couple of weeks and then I noticed it became muddy. And ya he sure did like using those, do you think those are worth replacing or just putting heat shrink over them? I'll check the Dale's tonight.
     
  4. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

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    What Brand/model spkrs are you using?

    We don't know if the caps were just installed right before you bought it or they had been in it a while. If they are K-40-Y Russian's they can change slightly, usually opening up in the mid and high ranges. Vit-Q's I've never heard. But using one type/brand/model cap tends to impart the cap's tonal qualities(I hear it more in a paper in oil cap) on the unit they are installed in. This is one of the reasons I mix up the caps between DME's, IC yellow mkp's, and Original ERO-FOL's.
     
  5. healyc139

    healyc139 New Member

    Messages:
    20
    Location:
    Chicago, Illinois
    I have Klipsch Quartets with Bob Crites Crossovers. Love em.

    Looks like the caps are K-40-Y's. What would you use for those if you were going to replace them?
     
  6. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

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    Replace the output couplers with Illinois Capacitor mkp's (yellow caps @ AES). .068uf 400v. test. If no change it's further back in the chain. Tone controls, C81 & 82 off V11, I'd use Cornell dublier DME's @ 600v rating. Don't change the value here. Test again. If no change I'd think your tubes need looking at. Especially the output's. What are your outputs and the 12ax7's at V10-V11-V12-V13.
     

     

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  7. sberger

    sberger Hard Core Geezer Subscriber

    Just a comment on the 7868 tubes. I'm currently running a restored Fisher X-100-B integrated with 7868's, and that amp has a lot more bottom end/grunt(maybe some would call it boominess, I just consider it a very typical, early 60's tube sound. And I love it. Contrast that with my restored 500C and it's 7591 tubes and that is much more neutral, less bass, not quite but almost solid state sounding. Perhaps your 400 and it's was breaking in over the course of a couple weeks and what you're now hearing is what it's signature sound is. I haven't owned a 400 in several years but I definitely remember it as not being as dry as the 500C is. I also had a X-101-C (7591) for awhile and it too was more neutral then my X-100-B.
     

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