Join Gretsch-Talk Today

Mud switch not working...

Discussion in 'Technical Side of Things' started by englishman, Feb 11, 2017.

  1. markeebee

    markeebee Country Gent

    Hey Eman, you mentioned in another thread that the Billy Bo sounds a bit muffled....I think I might know why.

    The switch that your using, in the configuration it's in, doesn't allow you to completely switch out the capacitors from the circuit. In the up position you select one cap, in the down you select the other, in the middle you effectively select both caps in parallel.

    When you connect two caps in parallel you get a lower value than either of the individual caps. Usually with standard Filtertrons, not a problem. With higher output TVJ it may be a problem because the frequency that your excluding is a product of the resistance of the pickup resistance.

    So I took a switch apart and reassembled it in a way that might help. the centre position neither of the switch contacts are touching (not the greatest pic ever, but hopefully you can see):


    And when you flip the toggle one set of contacts engages (when you flip the toggle the other way, of course the other contacts engage):


    So the result is a switch that gives Zero Mud in the centre position.

    I offer absolutely no guarantee that this will cure any problem, because they may be something else oddball elsewhere, but the physics makes sense.
  2. markeebee

    markeebee Country Gent

    Here's a diagram I drew a while back which might explain better:

  3. englishman

    englishman Gretschified

    Apr 5, 2014
    I do wish this were the case. I literally cut the tone switch out of the circuit and there was no change to the muffled-ness.

    As you can see here, the center position isn't connected to anything. and until I bent the interior blades a little, the other positions weren't working either.
    It works as it should now but alas, isn't responsible for the dull sound.

    FullSizeRender 2.jpg
  4. markeebee

    markeebee Country Gent

  5. stevo

    stevo Country Gent

    May 1, 2012
    Still muddy? I would cut the pickup switch out and wire in one pickup at a time.

    And for the record, I never use the stock capacitor values for the mud switch. I always work with lower values.