Difference Between Ppimv And Jose Master Volume?

Discussion in 'The Workbench' started by Julian Wong, Aug 12, 2018.

  1. Julian Wong

    Julian Wong New Member

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    Hi everyone! I currently own a 1976 JMP 50 and i'm looking to install a Master volume to make it bedroom capable. I was just wondering whats the difference between a PPIMV and Jose Master volume? Characteristic wise and what not. or will you guys just recommend running a attenuator? Hope to hear from yall soon! Cheers!
     
  2. slagg

    slagg Active Member

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    Jose Master is Pre Phase inverter and uses diodes
     
  3. Trapland

    Trapland Well-Known Member

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    I recommend running an attenuator.

    But PPIMVs sound nice too at real band volumes.
     
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  4. Michael RT

    Michael RT Well-Known Member VIP Member

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    PPIMV!!!
     
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  5. ampmadscientist

    ampmadscientist Well-Known Member

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    The attenuator is one method, the PPIMV is another...Jos'e is another
    but two or several can be combined.

    In the PPIMV, the phase inverter is over-driven, and the power tubes are attenuated.

    In the Jos'e, the phase inverter and the power tubes are attenuated.

    The PPIMV allows overdriving the phase inverter. In the Jos'e, the phase inverter does not overdrive.

    The phase inverter is adding an addition stage of overdriving---producing more overtones / harmonics.
     
  6. Fusedbrain

    Fusedbrain Active Member

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    The Jose master is not only before the phase inverter, it is usually installed between the cathode follower and the tone stack, along with the diode clippers. It's a unique sound for sure, with a ton of overdrive added to the amp. A lot of times the diodes are on a switch, or 2 different values of diodes are used for 2 levels of overdrive.
    If you just want to control the overall volume of the amp, go with a PPIMV. It wont sound spectacular at bedroom volume, but it is very effective at making a 50 watt plexi style amp gig-able in a club.
    Note that the PPIMV is inside the negative feedback loop. As you turn down the MV, you're reducing the amount of negative feedback, and the amp can start to get a little fizzy / hairy sounding. I have had the best results with this when I decide on the most commonly used volume level setting of the PPIMV and then adjust the NFB resistor to suit that setting.
    Or put 2 different NFB resitors on a switch. One value for high volume, One for low volume.
     
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