Considering converting my Conklin GT-7 to a six-string

Discussion in 'Luthier's Corner' started by Jehos, Jun 14, 2019.

  1. Jehos

    Jehos

    Mar 22, 2006
    DFW, TX
    As the thread title says, I'm kicking around the idea of converting my Conklin GT-7 to a six-string. Seven is too much, but I *really* love the sound of this bass. There's some magic going on with the pickups and preamp that I just love for rock, punk, and slap.

    On that last note, slapping is tough with the 16.5mm string spacing and my big fat fingers. However, it looks like if I ditch the 7th string I can fit six strings at either 18.5mm or (hopefully) 19mm.

    My thought is to remove the current bridge and nut, install probably a Hipshot A of the correct string spacing, drilling new mounting holes where necessary. The bridge seems simple enough too. I'm eyeing a Just-A-Nut from Warwick if they make one the right size, just for maximum adjustability. If not, I'll probably be sanding and filing down a blank from Graph Tech unless someone has a better suggestion.

    I'll probably be using the bottom 6 tuning pegs. The 7th I can just fill with...I dunno, something. I'm picturing like a medallion or coin or something I can attach somehow to cover up the hole.

    Is there anything I'm missing? Does this seem doable? I know I'll be slightly decreasing the tension on the neck, but I figure the double truss rod can handle it.
     
  2. dwizum

    dwizum

    Dec 21, 2018
    Pickups. I don't know what Conklin use but some will have dead spots between the strings, ie bartolini's split coil j pickup which is basically two inline coils - there's a gap with no sensing that falls between the string spacing each model is designed for, which means you can't do funky things like use their 5 string pickup on a 4 string bass, since doing so puts a string right in that gap.

    You could try to determine if your pickups would be affected like this ahead of time, or just do the conversion and try it out and replace them if there's an issue.
     
    TrustRod likes this.
  3. Jehos

    Jehos

    Mar 22, 2006
    DFW, TX
    Thanks for the tip. From what I can see of Bartolini's current offerings, it looks like what's on there is some version of a 6-string pickup already. It's almost certainly the Korean-made Bartolini MK1 pickups with a different preamp. From what I can find, there wasn't a 7-string version of that pickup unless Conklin was having them custom-made.

    It looks like the MK is a housing size designation from Bartolini. All their current versions of that pickup are blade-style, so I'm going to cross my fingers that the same was true with the Korean parts from back in the 1990s.
     
  4. I used to have one so I’d seen a lot of different ways gt-7’s have been modded.

    Anywho the one I saw that was converted to a wide spacing 6. they removed the d string tuner so it was a 3x3 symmetrical headstock and replaced the bridge and nut. I wouldn’t worry about the neck at all as far as tension and stuff. That’s one of the best aspects of that particular bass. The neck is massive and with the two truss rods it’s super stable. More so than any other bass I’ve owned. I only saw pictures so I can’t confirm if it changed the sound or if it worked properly. But I have seen it done. I would just confirm that the pickups will work good with the strings being moved over (I wouldn’t think it would be an issue but it’s a possibility)
     
  5. TrustRod

    TrustRod Supporting Member

    Mar 13, 2016
    Northern California
    16.5 on a 7 string comes out to 19.8 on a 6. (16.5 x 6 / 5) So 19 is doable, you'll have a bit more overhang up the neck but that should be fine.

    If Conklin used a dual coil Bart you're golden and it will work perfect. I just tested a Bart Split Inline by tapping the surface with a screwdriver point while it's plugged into an amp. You can clearly hear where the dropout is by slowly tapping across the length of the pickup a millimeter at a time or so. So no dropout = good for a 6.

    The Bart will be a blade either way whether it's a split coil, inline split, or full length dual coil. Conklin should be able to tell you what you have.
     
  6. TrustRod

    TrustRod Supporting Member

    Mar 13, 2016
    Northern California
    I would trim the headstock to just under the hole from the empty tuner. Something like....

    ds_Conklin_GT7_006.jpg