Fisher X1000 EL34 troubles

Discussion in 'Fisher' started by asech, Jun 25, 2018.

  1. asech

    asech AK Subscriber Subscriber

    Messages:
    301
    Location:
    Mission Viejo CA.
    I have a Fisher X1000 that is not getting good stereo separation, when the contour is turned to the max, the right side is much lower than the left, I ran a test signal from the internet and the left side produces the right and left signal through it but nothing on the right side until I turn the contour closer to mono...or turn it up a lot
    I just fiddled a little more with it and it seems to even out the right/left with the volume at 11 oclock and then favors the left side at higher volumes, using headphones....
    all tubes check ok, thinking now it may be the volume control worn out.
    any one know the specs for that control? is it 500K?

    thanks in advance,

    Andrew
     

     

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  2. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

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  3. AlTinkster92

    AlTinkster92 AK Subscriber Subscriber

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    Andrew, just a thought, have you cleaned all the controls with Deoxit? Might help.... Al
     
  4. asech

    asech AK Subscriber Subscriber

    Messages:
    301
    Location:
    Mission Viejo CA.
    Thanks Larry,
    I will wrestle it up on the dining room table and open it up, If there is no blending after they are disconnected, should be that pot and not the volume?
    Al, yep they were cleaned, I'm worried that was part of the problem, wiped the contact clean of the copper
    Strange this is when the volume is turned all the way down there is still signal fro the left side...
    i'll let you know what I find...

    Thanks
    Andrew
     
  5. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

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    With the Stereo Dimension control turned to the full Mono position and the Balance Control centered, do you get even sound from the speakers or headphones in this scenario (at any volume level)? If so, then any imbalance when the Stereo Dimension control is set to its normal Stereo position is occurring before the Dimension control in the circuit. If the sound is still unbalanced with the controls set as instructed, then the imbalance is occurring in the power amplifiers or Balance control.

    When the Stereo Dimension control is turned to the full Stereo position, it is completely removed electrically from the circuit, so disconnecting it will not likely resolve the issue.

    Let us know the results of this test, which will then guide any further troubleshooting required.

    I hope this helps!

    Dave
     
  6. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

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    No. The Dimension pot is is the last control before the Amp. phono pre amp to amp controls are as follows: Low Level, Low Filter, High Filter, Loudness, Volume, Bass, Treble, Balance, Dimension. When you cleaned the controls with DeOxit D-5, did you follow up with either Faderlube F-5, Gold G-5, or CRC Electronics lube. This is important as the DeOxit D-5 does not lubricate, allowing increased friction and subsequent removal of the conductive track to the point where it's completely removed. This takes a good amount of time but it's possble to happen, but not overnight. The CRC is the easiest to get as it's at Home Depot.

    I had some tests for the Balance and Volume contros for you but Dave's instructions will cover those better.
     

     

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  7. asech

    asech AK Subscriber Subscriber

    Messages:
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    Location:
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    Dave,
    first, Thanks
    with the Stereo Dimension at full mono, the volume is the same on both sides, when turned to full stereo, the right side cuts out.
    another thing while at full mono, turned all the way down there is still sound from both sides...?

    Thanks to all,

    Andrew
     
  8. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

    Messages:
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    Location:
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    OK, then the balance control and power amplifier sections have been eliminated. Then with the Balance control centered and the Stereo Dimension control set to full Stereo, remove the rubber cover over the connections within the dummy plug install in the Remote Control jack, to reveal two jumpers soldered to the terminals of the dummy plug. Using an alligator jumper clip lead, short the two jumpers together. If the sound evens out, the imbalance appears before that point in the circuit. If there is no change, then the problem is in the tone/volume control circuits.

    If there is still significant sound with the volume control turned full down, then the first step to resolve that (if not already done) is to replace the power supply can cap labeled as C38 on the Fisher schematic (located over near the phono preamp tubes).

    Let us know!

    Dave
     
  9. asech

    asech AK Subscriber Subscriber

    Messages:
    301
    Location:
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    Dave,
    used a tweezer and jumped the two wires on that plug, only the left side got louder, no change to the right...
    All the cans were changed out from Tom at Hayseed about 3 years ago,

    Andrew
     
  10. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

    Messages:
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    Location:
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    OK. If the can cap is good, then that eliminates that as a possible leakage path for the low volume leak. Please describe the sound: Is it full bodied but weak? or weak and tinny sounding?

    Next. With the controls set as before, short the center terminals of the two volume control sections together and see if the sound evens out. If it does, then the issue is the volume control. If not, then the problem lies within the tone controls.

    Let us know!

    Dave
     
  11. asech

    asech AK Subscriber Subscriber

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    Location:
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    Dave,full body but weak/low

    not sure what two terminals on the volume control sections you mean, are they on the pot?
    Thanks and heading to work...
    Andrew
     

     

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  12. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

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    Yeah they are on the Volume pot. There are 3 terminals on one side, and if the loudness is tied to the pot, one on the other side. The center pins of the pot (2 sets of pins for a total of 6.)get shorted together.

    Looking from the End of the pot the center pin on both sections get shorted together(arrow pointing to) while the unit is playing. Report results.
    Pot from End.JPG
     
  13. asech

    asech AK Subscriber Subscriber

    Messages:
    301
    Location:
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    Thanks Larry for that, I got it now,

    Will report later,

    Thanks all...!
    Andrew
     
  14. asech

    asech AK Subscriber Subscriber

    Messages:
    301
    Location:
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    Larry/Dave

    had the first chance today to go through the steps you provided, when I shorted them together it evened out volume wise,
    Volume Switch?

    Thanks,
    Andrew
     
  15. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

    Messages:
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    So the volume control itself is the issue. Sorry to be the bearer of bad news, but at least you know.

    Dave
     
  16. asech

    asech AK Subscriber Subscriber

    Messages:
    301
    Location:
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    Dave,
    would that also be the cause of the bleed over from from A channel to B channel, when I ran a stereo channel test, I got sound from both signals
    through one channel......
    I will try and source one, but what I saw inside is over my head....
     

     

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  17. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

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    During the test, the unit was in fact operating in mono mode, regardless of how any controls were set.

    In normal operation, with the mode selector switch set to Stereo, and the Dimension control set to Max, then a Channel A signal should only come out of the Channel A speaker, with the same scenario applying of course with Channel B.

    Do make sure that you are not confusing the Dimension Control with the SpaceXpander control since they appear together. The outer ring (SpaceXpander) should be set fully counter clockwise, while the inner (Dimension) should be set fully clockwise.

    Dave
     
  18. asech

    asech AK Subscriber Subscriber

    Messages:
    301
    Location:
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    I will test again, I had them both fully clockwise.....

    Thanks
     

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