Doing a lefty run

Most of us builders will make left hand instruments for minimal or no additional cost. We generally make all of our patterns, routing templates, and fixtures so that they can be flipped over. It doesn't take me significantly longer to make a left hand Scroll Bass, and I don't charge anything extra. It's mostly a matter of project management; remembering to flip over all the steps for that one instrument. Lots of little details. The wiring has to be modified to reverse the rotation direction of the pots. The bridge saddles need to be assembled the opposite way. The nut slots have to be cut reversed. And then there's the left handed paint... Okay, I'm kidding about that one. The woodworking is mostly about reversing the patterns and routing fixtures.

It's more of a problem for larger manufacturers who have a fast moving production line. One oddball lefty in the line can mess up the efficiency. They don't want to hold up the line at each operation to do a quick reversal or fixture change. So, they will tend to stop the line, set up for leftys, and then run a batch all in a row.

 

Where did this weird notion come from that because we are lefthanded we do everything reversed?

I really hate it it when the wiring is reversed, it means I have think what direction I have turn the knob and almost by default I will do it the wrong way.
Whenever I buy a bass that has the wiring done this way one of the first things I'll modify is to reverse them back again.

 

I've wondered about that. So far, all of the customers that I've built lefty basses for have preferred the reversed pot rotation. But it's no problem to switch it if they ask.

One of my customers had me build his bass left/right; a left hand instrument with right hand stringing. The E string ends up on the low side. I guess a fair number of left hand players prefer that reverse pattern.

By the way, I'm left handed myself. I do almost everything left handed....except playing bass and guitar! For some reason, playing bass has always been more comfortable to me right handed.

 

If the pot is Audio Taper (i.e. Log), I would be very cautious if reversing its rotation, unless the pot is specifically designed with a reverse taper.

This is because the log taper pot is not symmetric. For example, if you move the cap on the tone pot from one of the outside terminals (of the 3 pot terminals) to the other outside terminal, you run the risk of the tone control having little effect until the very end of its rotation.

Here's an example of what I mean -- it's a table of resistance measurements I made awhile ago of the tone pot in a lefty Squier bass. Note that terminals 1-2 are the preferred terminals. If you use terminals 2-3, the amount of rotation it takes to go from, say, 100K ohms to 0 ohms is much less than the amount of rotation it takes to span the same range when using terminals 1-2. So, if using terminals 2-3, the effect of the cap will kick in much later, towards the end of the pot's rotation.

(P.S. Ignore my annotation "original wiring" and "new wiring" -- I'm not sure which wiring is actually original)

 

Oh yeah, I'm aware that a log taper isn't symmetrical. It doesn't matter in my case, because I use all linear taper pots in my basses.

My guess is that even a reverse-wired log taper pot wouldn't bother most people (assuming that they wanted it running reverse direction). How do most players actually use the Volume control? They normally keep it almost all the way open. If they are are too loud, they turn down small amounts by feel and listening, not by looking at the marks on the knob. Or, they go all the way off. Do you ever play your bass at 25%?

That's one of the reasons that I like the linear pots. The upper half of the rotation takes the volume down from Full to maybe 75%. Then the rest of the rotation shuts it off quickly. It gives you a finer adjustment in the part of the range that you actually use.

 

Hmm, that would be a luthier's nightmare to screw up a one-of-a-kind left-hand model in the middle of the build by accident.

 

I remember at least one time that I ruined a left hand neck by putting the side marker dots on the normal side.

 

Ditto me. I play bass right-handed because I started on guitar, and only had access to righty guitars, and also decided that left hand fingerwork was more important than picking/strumming with the less dominant hand.