Fargen MiniPlex "Decade Switch" tech?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Free, Jan 31, 2008.

  1. Free

    Free Member

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    I asked this question to Mr. Fargen, but he was either reticent to answer or didn't feel like explaining - bad customer service for me I'm sad to report. I was really disappointed to get that kind of response, because what I always appreciate most with great boutique makers is that they are always happy to elaborate technically on their amps, which I had purchased or was in process of.

    So, I'd thought I'd bring this question to TGP: Can someone please lend some insight into the "Decade Switch" that gives 3 different classic sounds/gain structures on the MiniPlex. Is this achieved via various cathode bypass caps? What is going on technically in detail with that feature? Thank you.
     
  2. Grimace

    Grimace Member

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    I have heard that it is indeed cathode bypass caps that are being switched. I have a Fargen Epic. Up, you have the Marshall -y .68 uF, down you have the Fender-y 25 uF, and in the middle there is no bypass cap. I have not confirmed this by opening it up, but the sounds I get in the three positions are consistent with this.
     
  3. Free

    Free Member

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    Thanks for the info, Grimace. Though I'm not an amp builder, I'm from the Dave Hunter "Amp Handbook" school of guitarists that like to know what technically makes these amps tick, so I appreciate the insight.
     
  4. 3th3r

    3th3r Member

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    On my Mini-Plex:

    80s = 22 cap
    70s = no cap
    60s = .68 cap

    I've seen circuits with this same arrangement that call the settings "Bright" (60s) and "Deep" (80s)
     
  5. Free

    Free Member

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    Thanks for the reply. Right on - I don't get it. Fargen amps calls it a "patented 'decade switch'", but as far as I can tell it's a long common "bright" - off - "fat" bypass cap boost arrangement that makers like TopHat have been using for over a decade - traditional Marshall bright cap at .68 and the 22-25 uf range "fat" boost that so many makers have always used. Interesting.
     

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