Question on Silver Face Dual Showman Reverb

Discussion in 'Amps and Cabs' started by lovehifi, Jan 25, 2015.

  1. lovehifi

    lovehifi Member

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    I bought a used 73 SF Dual Showman Reverb at a great price. It sounds great. However I am trying to figure out the master volume and also to see if there are any previous mods to it. On my amp with the master volume turned to zero I still get sound and plenty of it. Is this normal or should it be muted with the MV on zero? As I turn up the master volume it seems to sound more open and the highs seem to come to life. I am clueless on Fender SF amps as I have never owned one until now but to me the master volume on my amp almost acts like a presence or tone control. What am I supposed to hear on a stock SF amp with a Master Volume and while using the master volume what tonal and volume changes should I hear IF everything is stock and with no mods? Thanks.
     
  2. Heady Jam Fan

    Heady Jam Fan Member

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    Hmm, that doesn't sound right to me. If your comfortable, take the amp out of the cabinet and take some pics of the guts. Or just take the amp to a tech - a good idea any time you get a vintage amp.
     
  3. lovehifi

    lovehifi Member

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    Thanks. I am taking it to a tech tomorrow to have it gone over. I read of a mod called a Jimmy Switch mod or something like that which turns the Master Volume into a Presence control. Who knows but I would prefer it be put back to stock and go from there. I am going to have new power tubes put in and have it biased as well. Caps are new except for the bias cap and it looks rough. Might be why my normal channel doesn't have the volume of the vibrato channel. In saying all that this amp sounds great and since I only spent a few hundred on it I don't mind putting a few more $ into it. At least now I know what I am experiencing with the master volume isn't normal. Thanks again.
     
  4. Heady Jam Fan

    Heady Jam Fan Member

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    Great man! Congrats on the purchase.

    I had a Twin with a Post Phase Inverter Master Volume (PPIMV) and I personally prefer no master volume in that circuit. I never set it lower than 7 on the dial. The only Fender I ever thought sounded good with a PPIMV was a Bassman. I was thinking it could be a presence control, which, in a Fender, is usually a negative feedback control (NFB). Increasing the presence would be decreasing the negative feedback, which not only adds presence but lowers headroom.
     
  5. Greentone

    Greentone Member

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    Your have just discovered that master volumes sound lousy, especially in Fender circuits. Place it on "10" and forget about it.
     

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