Adding a string to an SSI - 5 to 6 string conversion

[Sean Fairchild]

Before anyone flips out, I'm not saying I'm going to be doing this! I guess this would be applicable to any broad neck 5 string, not just the SSI 5-string.


I was curious a few nights ago, and took some measurements of my Streamer LX 6 (normal non-broadneck) and Streamer Stage I 5 (normal broadneck) and found some interesting similarities:

-while the nut is 5mm more narrow on the SSI-5, the fretboard is only 1mm more narrow at the 24th fret of the SSI-5 than the same position on the LX 6; a millimeter is totally negligible

-the bridge is also almost exactly the same size between them: same width, and 1mm difference between the two models (LX being longer). That's such a small difference that depending on the route, the larger bridge might actually fit in there on an SSI, albeit snugly

-the tailpiece is the only considerably different measurement (aside from the wider nut on the LX), being the same width on both models but several mm longer on the LX. And since it's a V shape, I'm not sure how close the routing would line up if one were to add an LX 6 tailpiece to an SSI-5, routing it out a bit more on each side


Conclusions:
You could do it - transform a broadneck SSI-5 into a normal neck 6 string, by routing the tailpiece route further out on each side just a couple mms per side, filing a new (non-Justanut) nut, and modifying the headstock.

The headstock modifications would amount to plugging the currently drilled tuner holes on the right side with pieces of a dowel, gluing into place; one could even make a dowel out of wenge/ovangkol with an ebony cap, then drilling 3 new holes that mirror the 3 tuner holes on the left side of the headstock.

String spacing would be tighter than on a 5/6 string LX at the nut, but almost equivalent at the 24th fret and over the pickups, where it's likely to make a difference for your plucking hand anyway.

There would be roughly 40 lbs of increased tension on the neck, which a broadneck should easily be able to handle if normal gauge strings are used (you could increase tension by 40 lbs by just using really heavy strings in the first place, so not a huge deal I wouldn't think).

So, food for thought

 

[DiMarco]

Interesting thoughts.

When changing strings on the LX, unscrew the tailpiece and see if it fits into the SS1. Best way of finding out for sure.

At first I couldn't play regular 16.5mm stringspacing and prefered broadnecks, but ever since switching to the Dolphin 5 and now the SS2 5 I even prefer 16.5mm spacing to broadneck.

Pole pieces on the SS1 pickups are the only problem I can think of, will they handle 6 strings instead of 5 properly?

 

[Sean Fairchild]

Most of the pickups you're likely to see on an SSI-5 use bar magnets; standard MEC and my Aguilar DCBs included, so pole pieces aren't an issue. The tailpiece won't fit for sure; it was one of the only elements that would require further routing, but I could see how close it would come. I think the LX tailpiece was something like 3-5mm longer, I've got it written down somewhere.

I have been all over the place with string spacing, and for the most part what I find is that I get used to whatever I'm using after a short while. That said, I seem to gravitate towards roughly 17-18mm spacing, widening the spacing on my SSII and narrowing it on basses with larger spacing. In the end, I don't think it's as big an issue as we sometimes make it. I could play a 6 with 16 or 16.5mm spacing without issue if I played it for a week or so.

 

[theBassPark]

This looks like a crazy but interesting idea.
But the Pickups should be concerned. SSI's pickups have asymmetric split coils. Bart or Basslines dual coil PUs would be fine.

 

[Sean Fairchild]

theBassPark,
With the MECs, they're offset split coils similar to a P configuration, aren't they? That's how the 6 string ones work, although in a 6 string they're symmetrical. However, there isn't a gap between the coils, so a string anywhere along its length should be sensed by one of the two coils. Maybe if a string fell right on the division between the two it would have a different tonality than the others.

The Aguilar DCBs that came in my SSI are just parallel bar magnets. Any bar magnet design would work, I'd think. The Basslines are just like MECs - split coils in a reverse P style configuration, I think. Bartolinis vary in their internal configuration.

 

[theBassPark]

I don't know exactly how the vibration on the split will affect its sound either but at least I guess the string's volume will be different from others'.
As you said, your SS1 has Aguilar DCBs then no worries