Questions about treble boost mod

Discussion in 'Fisher' started by thornev, Apr 26, 2018.

  1. thornev

    thornev Well-Known Member

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    Thanks, Dave451. This is a big help. Thorne
     

     

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  2. thornev

    thornev Well-Known Member

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    868
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    Dave451... Can you upload that schematic with a better resolution? I cannot read it when I print it. And it doesn't agree with the full v13 schematic. Thanks, Thorne

    PS - The full schematic shows R99 and R100 to be 47K whereas the Unity Gain shows 10K. Which is it? And the full schematic shows a 1M after J12 amd J16 that are not on your schematic?
     
    Last edited: Dec 16, 2018
  3. Dave451

    Dave451 AK Subscriber Subscriber

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    I pulled that from the "sorta final" version on the "Improving the Fisher 400" thread. This was the one in post #103. Have a look at the thread and get the latest (there are 17 pages!). I thought it was final, but it may not be. The 1M resistor rings a bell.
     
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  4. Dave451

    Dave451 AK Subscriber Subscriber

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    For the unity gain buffer, use Dave G's hand-drawn schematics for the resistor values. That's what I used and mine worked very well on my 400.
     
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  5. thornev

    thornev Well-Known Member

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    868
    Location:
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    [OFF TOPIC] I didn't want to start a new thread just to brag. I purchased a set of Westinghouse 7591's from 1966, put them in my 500-C, and OMG ! The clarity and fullness is amazing. They made my AR-2Ax speakers come alive, shooting out frequencies, especially in the high register, that they never had before. I also tried some old Sylvania's that were really nice, but I am sticking with the Westinghouse. Brag over.
     
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  6. 1rebmem

    1rebmem AK Subscriber Subscriber

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    Wilmington, NC
    Thanks for this Thorne!
    I also have a nice set of NOS Westinghouse tubes to try in my 500B.
    I've read where some people said the USA made 7591's sound much better than new production and others say the new versions are just as good.

    I will find out.......someday.......
    Jef
     

     

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  7. thornev

    thornev Well-Known Member

    Messages:
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    Ya know, Jef, I've been reading forums about Fishers and other receivers, and about speakers for a long time, and the only conclusion I can make is that given a population of 100 people who all listen to 10 different audiophile stereo systems, you're likely to get 50 different opinions about which configurations sound the best. Some people like bass-heavy, some like treble-heavy, some like flat response. Some people appreciate the lightest of cymbal taps, some people want to have their pants blown off by kick drum hits. I know what I like and I like what I know !
     
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