Further Mid Scoop on a Fender Tone Stack?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Lonely Raven, Dec 11, 2004.

  1. Lonely Raven

    Lonely Raven Member

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    I need to scoop or at least shape the mids better on the
    Normal channel on my Super Reverb. The Normal channel
    has just Bass and Treble, so if I remember correctly it's like
    a 15k resistor to ground right?

    What can I do with that kind of setup to get more of a mid
    scoop, or shift where the mid scoop is? Until recently I've
    never had a need to mess with the Fender Tone Stack, but
    I'm trying something new out, and I desperately need to
    tweek the mids a bit now.

    Any suggestions are greatly appreciated!
     
  2. KLB

    KLB Member

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    If he wants to SCOOP the mids, he will want a lower value resistor, perhaps 1K to start.
     
  3. Lonely Raven

    Lonely Raven Member

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    Thanks guys, that's the info I was looking for!
     
  4. Jon Silberman

    Jon Silberman 10Q Jerry & Dickey Gold Supporting Member

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    This is likely obvious already but just in case - mid-scooping that sounds nice at home can get completely lost in the mix on a stage.

    Why not get the best of both worlds (as I did on my Tone King Continental) by replacing the stock resistor with a pot that runs from, say 6-20K? You retain the stock look of the amp by mounting it on the back or even bottom of the chassis.
     
  5. WailinGuy

    WailinGuy Member

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    The main reason why the normal channel doesn't sound as scooped as the reverb channel is that the normal channel is voiced to have signficatntly more bass and lower mids. So lowering the mid resistor from 6.8K may help a little, but probably won't be enough to give you the tone you want.

    To make the normal channel sound closer to the reverb channel, try replacing the .047 cap connected to pin 6 ov V1 (2nd stage plate cap) with one of a smaller value. Start with .0047 and experiment from there. You might even want to go as low as .0022 or .0015. Since the signal coming out of this cap is not being severely loaded down by the 50K INTENSITY pot (as is with the reverb channel's signal off of the 3rd stage .1 plate cap), a smaller value should still pass plenty of bass frequencies.
     
  6. KLB

    KLB Member

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    Yeah, that .047 on the Normal channel is there to make up for the lack of a 3rd gain stage. That's why the normal channel usually sounds cleaner at any given volume level than the Vibrato channel.

    When someone talks about "mids", they rarely say what mid FREQUENCY, so it's hard to know what they mean...

    Getting an EQ pedal and playing with it will go a long way to educating the ear about what specific frequencies you find lacking or too prominent. Simply putting an EQ pedal in front of the Normal channel may be all that is needed, rather than modding the amp, plus you get more control over the tone.

    I recommend the Tone-Jam modded Sniper BOSS GE-7. It's small and very quiet.

    Cheers,
    Ken
     
  7. Lonely Raven

    Lonely Raven Member

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    Thanks much for the added info guys!

    Jon, the pot on the back of the Chassis was exactly what
    I was thinking of.

    And as for modding this amp, it's a Bandmaster Reverb that
    came to me with a badly corroded chassis, burnt out PT
    and reverb trannie, tubes in the wrong spots, and overall
    just a mess.

    I've rebuilt it to BF Super Reverb specs, dropped it into a
    Super Reverb cab I saved from someone else, and it's my
    third Super Reverb...so I feel comfortable that it can handle a
    little bit of modding, though I of course refuse to drill it at all.

    As for why I'm doing this...well, I've discovered the Hicks
    Mender, and I'm absolutly in love with it! It brings a whole
    new life to my BMR/SR conversion. I've got somewhat of a
    Marshall like sound and my first thought was to tighten it up
    and scoop more mids for a bit of a Metallica sound, while still
    retaining the clean vibrato channel that I love so much!

    I figure after I play with the Metallica mid scooped thing for a
    bit, I'll go back and look at some Marshall circuits and see if I
    can make it more Marshall sounding without making a mess of
    things.

    Just another step in my amp building/repairing education!
     

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