Is there a way to reverse sperzel tuners?

Discussion in 'Hardware, Setup & Repair [BG]' started by Big B., Jul 10, 2013.

  1. Big B.

    Big B.

    Dec 31, 2007
    Austin, TX
    Just picked up a set of these at a great price. Unfortunately the set is 4 inline but the bass I am building is a 2 by 2 configuration. It wasnt until I recieved the tuners that I realized that the bass tuners are not designed to be reversed, only the guitar tuners. :scowl:

    Not that big a deal really. I build enough basses that buying another set wont be a problem but if there is a way to reverse them that would be even better. Apparently the warranty is void if the swap is attempted but I'm okay with that.
  2. iiipopes

    iiipopes Supporting Member

    May 4, 2009
    Do they even disassemble? I didn't think Sperzels did? But even if they do, it's the direction and bias of how the worms are cut that determines the way they wind, not the direction of the ear.
  3. Big B.

    Big B.

    Dec 31, 2007
    Austin, TX
    The locking guitar tuners disassemble and can be reversed but apparently not the locking bass tuners.
  4. Bruce Johnson

    Bruce Johnson Gold Supporting Member Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    I'm pretty sure that the left and right hand Sperzel tuners use all the same components, but they are put together opposite. The turned "neck" of the housing is a separate part, which is pressed into the rectangular housing block. It can be pressed into the hole on either side. The key shaft then slips in through the opposite side hole, and a little plug is lightly pressed in to seal that hole and hold the grease inside.

    To disassemble it, you first take off the key. Then tap lightly on the end of the key shaft, which will knock out the plug on the far side. Then slip the key shaft out through the hole. Then theoretically, with the right arbor setup, you could press the neck out of the housing, reverse it, and press it back in the other side. Practically, you'll probably scratch up the anodizing in the process. So, it's probably not worth the trouble. I've never tried taking a Sperzel apart, so I don't know how much force it takes to pop the neck out of the housing. I'm sure that they press them together before the anodizing.

    By the way, right hand and left hand tuners both use the same right-hand thread gears. When you flip the key shaft over, you are effectively putting the key on the opposite end of the shaft, which makes it turn the other way. But it's still the same right-hand thread gear, even though the tuner effectively turns the opposite direction. Don't get a headache trying to visualize that!

    I've only seen a few specialized tuners that have actual left-hand thread gears. The ones I'm most familiar with are the Klusen bass tuners that were made for Ampeg, and were used on the horizontal Scroll Basses and the Baby Basses, which both have scroll-style headstocks. At first glance, the Ampeg Klusens look just like the Klusens on many early Fenders and Rickenbackers, but if you look close, the gears on the Ampeg Klusens go the opposite direction. Both the gear and the key shaft with the worm are special parts used only on the ones sold to Ampeg. All four tuners in the Ampeg sets have left-hand gear sets, but two are assembled with the key to the left, and two are assembled with the key to the right. Just something to watch out for if you are scrounging junk-box Klusen bass tuners.