Hey - Hold my beer, Watch this!

Our friend SCompracer already modded the bajezus out of the Music Hall 25.3 and it is recorded here somewhere ( http://forum.polkaudio.com/discussion/127985/music-hall-25-3-dac-mods-belleson-super-regulator ) what he did. I purchased this with one of the Burson op amps burned out due to a mispin by the next owner. I returned it to good condition and have been using it for a couple of years.

It's no fun just leaving things as is... Time to upgrade it further!
All I did was replace the output coupling caps. I used Clarity Cap CMR 3.3uf 400v caps (smaller voltages are not available in this cap). They are just a tad bigger than the M Caps that were in it (by a factor of 4x or 5x!).
ycodj2ec8omk.jpg

I use this DAC to feed my Bottlehead Mainline headphone amp with Sennheiser HD800s headphones so I don't feel to bad about putting a bit more into this DAC.

Before we begin - where we started and what we're putting in.
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Board removed from the chassis and the original caps pulled.
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New caps installed. I use double sided tape to keep them from banging against each other and to stabilize them.
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Heat shield around the tube.
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Hey! Give me my beer back. The darn thing still works!!!

Comments

  • EndersShadowEndersShadow Posts: 14,199
    Slacker. I still see WAAYYY to much empty space in that case. You need to mod it more!

    Maybe an interior linear powersupply....
  • pitdogg2pitdogg2 Posts: 6,575
    Good god man they're fargun Uuugh. Just enough room for the heat shield.
    Nice job
  • mrbironmrbiron Posts: 4,134
    Look at those Op Amps!!!

    My father once told me, "if you'd stop playing with it, it would actually grow..."
    Can't just leave things alone can you. B)
  • heiney9heiney9 Posts: 23,341
    Schweet!
  • Jimbo18Jimbo18 Posts: 1,402
    In this neck of the woods, the saying is more like "Hold my beer, wa-chiss".
  • ALL212ALL212 Posts: 570
    edited May 26
    Just when you thought it was safe to go outside. :*

    I forgot I still had the non-burned out Burson. I saw a picture with the Burson installed in the little headphone board...hmmm....

    The original Burson is a gen prior to the ones I purchased. I don't think that's a big deal but I could not use the old Burson in the headphone amp as it had an extra socket soldered to it. That extra socket was there to lift it above the caps over on the main board. However, the new Burson wasn't soldered to an extra socket.

    I used the new Burson in the headphone amp and the older one in the main board.

    Next - I see two tiny electrolytic caps on that headphone board...there must be a way to make those film caps. B)

    Original Burson on the main board.
    rqrrzq9pmbq9.jpg

    Newer Burson on the headphone board.
    1mzt3egqpcda.jpg
  • SCompRacerSCompRacer Posts: 6,364
    edited May 26
    I was surprised it still worked after that poor fellow plugged the Burson in backwards. One of them Belleson Superpower regs musta been sweating at full output. Good thing I did the sink upgrade..... That Burson had a Viking funeral.

    Nice work! You think the headphone PS has got the torque to run that Burson? Them first gen's were mA power hungry. I forget where headphone power originates. Too bad you sold your scope...want to buy another? :smiley:

    I picked up one of these handheld Fluke 123's and fixed the screen issues. Been my goto scope. Much lighter than the old Tektronix.

    s-l1600.jpg
  • ALL212ALL212 Posts: 570
    Still got the scope!

    I used the old one on the main board so it can pull from the power you supplied!

    The new one is on the headphone board. So far no smoke at all... :#
  • FaustinFaustin Posts: 650
    Nice! Love to see those "explosive size" caps in the mix. Let us know what you think as they burn in.
  • SCompRacerSCompRacer Posts: 6,364
    edited May 27
    Faustin wrote: »
    Nice! Love to see those "explosive size" caps in the mix. Let us know what you think as they burn in.

    Please, don't mention explosives to Aaron! ;)

    I think you gave me the one of the matched pair that survived?

    They had dink-sinks in there before.

    mh253_3.jpg

    Don't touch the silver things! They will rectify you.

    sinked_2.jpg

    Old shot with deadmouse, pre litigation days....

    deadmousedac.jpg

  • ALL212ALL212 Posts: 570
    I've wondered where that last Burson went! :o

    Boom? Bang? Kapow? BOOM!!! :* o:)
  • SCompRacerSCompRacer Posts: 6,364
    edited May 27
    ALL212 wrote: »
    I've wondered where that last Burson went! :o

    Boom? Bang? Kapow? BOOM!!! :* o:)

    You want it back? I haven't used it. My DAC is running on discrete balanced.

    For kicks you could plug it in backwards and power it up. :o >:)

  • FTGVFTGV Posts: 3,483
    SCompRacer wrote: »
    for kicks you could plug it in backwards and power it up. :o >:)
    Yeah do it with lid off and post video. :) :
  • ALL212ALL212 Posts: 570
    5bq0von4wugk.jpg
  • SCompRacerSCompRacer Posts: 6,364

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