Modding/fixing 1959HW

Discussion in 'Building the Classics' started by Chris4189, Sep 11, 2019.

  1. Chris4189

    Chris4189 Well-Known Member

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    All,

    I need some direction. I like to tinker around with things and try to be as self sufficient as possible and fix my own crap and have learned a lot along the way.

    Here lately I’ve gotten the bug to tweak an amp. Locally, I’ve found a 1959HW with a blown OT and the seller wants out of it because it’s too loud and doesn’t have enough gain. He is asking $1k for it which isn’t a bad price at all. I’ve pulled the chassis and it’s bone stock:

    I would like to throw a Merren or Heyboer C1998 in it and take it from the ‘69 metal panel circuit back to a ‘68 plexi circuit. I kind of have a rough idea of what needs to be changed due to some info I dug up on the old metro forum. Where can one find good accurate color diagrams at where each individual part/value is represented etc? I have attached a file for the type of diagram I’m looking for.

    I know many would say buy a Germino etc but I want the satisfaction of doing it myself and if I say screw it one day and want it to change it to 10,000 circuit I can.
     

    Attached Files:

  2. neikeel

    neikeel Well-Known Member

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    https://forum.metropoulos.net/viewtopic.php?f=26&t=11957

    Take a look at the pdf in the file above.

    I agree a Merren or Marstran C1998 is the way to go.

    The preamp board on your HW should be the same as the 12 series. It is the filtering that is different.
    I suggest you buy:
    32uF/32uF 450v capacitor cans (ARS or F&T) x3
    You remove the two screens cans (the ones with the bleeder resistors) and replace them with the above, but for true 12 series specs only use one half of each cap in series 32+32 =16uF which is correct.
    Replace the preamp cap with the other can.
    MY two 68s both had 48uF on the PI can so you can try it with just one element of the existing 50+50 but a lot of the EVH fans stick with 100uF in the PI.
    Plug and play.
    Some people find that screen filtering too low (it is greasy in feel but you can get ghosting too) so the option of doubling up the other half of those cans by adding a link between the lugs can be a useful option.
    If you still want bleeders you can put a couple of 220k 2w resistors on the mains cans.
     
    Last edited: Sep 11, 2019
  3. Chris4189

    Chris4189 Well-Known Member

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    john hammond likes this.
  4. ampmadscientist

    ampmadscientist Well-Known Member

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  5. ampmadscientist

    ampmadscientist Well-Known Member

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    I think you are paying too much for it. You don't know how much it will take to make it work again.
     
  6. Chris4189

    Chris4189 Well-Known Member

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    Well I thought about that and it does have a blown OT so there is $200 off the top and probably another couple hundred in sozo’s, caps etc. so some of the stuff that could be affected by the OT I’ll replace anyway. What would you consider a fair offer? I’m open to suggestions.
     
  7. ampmadscientist

    ampmadscientist Well-Known Member

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    How do you know the power transformer is still good?
    And you will be buying tubes...
    If the output tranny is blown, the tubes are lunched.
    I wouldn't pay more than $500.
     

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