JTM 45 Build with Switchable Duel Master Volume

Discussion in 'The Workbench' started by Mike V Amos, Oct 25, 2020.

  1. Mike V Amos

    Mike V Amos New Member

    Joined:
    Oct 25, 2020
    Messages:
    3
    Likes Received:
    0
    Hi All,
    I have a jtm 45 meto amp build that I installed a SkipZ switchable duel master volume into. That board has gone bad on me and Skip is no longer in business. I'm not a tech but found this kit very easy to install a couple of years back. Does anybody here know where I might find a replacement board or know of something that I can easily replace it with. I love what it does!
     
  2. johan.b

    johan.b Well-Known Member

    Joined:
    Feb 21, 2015
    Messages:
    1,735
    Likes Received:
    1,988
    Location:
    Södertälje, Sweden
    Good pics of both side of the board. Fault description, including what it does and what it doesn't, and I'm sure someone here will be able to help you
    J
     
  3. Mike V Amos

    Mike V Amos New Member

    Joined:
    Oct 25, 2020
    Messages:
    3
    Likes Received:
    0
    Yea, makes sense! The amp is in my case and off site. I'll pull it this weekend, get some pics of the internal wiring and the board. Thanks! Bottom line. The mod added the Skipz board and 2 pots that control volume to the back of the case. A 1/4 to 1/4 runs from the board to a switch. The master volume is still in place and both pots dial in volume seperatly. There is no change in tone. So, if both pots are dimed then switching between them has no affect on tone or volume from where the master is set. Rolling one pot back only changes volume, not tone. (I'm sure it does a bit but is transparent in my live setting.) I can then switch between both pots. I use one as a rythm and the other as the lead boost. Does that help?
     
  4. Mike V Amos

    Mike V Amos New Member

    Joined:
    Oct 25, 2020
    Messages:
    3
    Likes Received:
    0
    ok, I found the original instructions and a picture of exactly how my mod is set up. I have normal master on the front. None of that has been changed. The Skip mod added two new pots on the back of the amp that controlled volume as well. There is a 1/4 to 1/4 that runs to a switch that allows me to switch between the volume settings on each pot. Both the new pots are independent and identical in tone. If both are cranked, there is no difference in master, pot1, and pot 2 on the back. If I roll volume down on the pots in back the tone is transparent. (I’m sure it’s not 100% transparent, but in my live setting it sure is close.) I use it for a boost on leads. Pot1 is my rythem and pot2 is my lead. Note that the total volume of the amp is still controlled by the master on the front of the amp. The max volume from either of the to pots on the back will not exceed the master.

    The amp actually works but does not switch. So basically, only one pot on the back is working. So, I feel like I just need to replace the board. I got things pretty hot when soldering a couple of years ago. See the diagrams below.

    [​IMG]

    [​IMG]
     

Share This Page