Anyone considered a 12-string conversion?

[NancyJohnson]

Thomann have a b-stock 7-string bass for £399.

 

https://www.thomann.co.uk/harley_benton_bz_7000_ii_nt_b_stock.htm

 

Over the years I've seen a few 12-string conversions (the first was off an OLP 5-string).  I see stuff like this Harley Benton and do wonder whether it would be ripe for a project.

 

The missus immediately vetoed the idea ("It's £400 and it'll cost you that again once you've tinkered with it, so no!").

 

How hard would this actually be?  Plug the headstock holes, new machines.  New (intonating) bridge and nut. 

 

Yes, people here would be going, 'String tension!', without really having the science to back up whether the neck would survive 

[warwickhunt]

I looked at converting a bass to 12 and the neck size, rigidity aside, the cost of parts started to stack up.  One of the big hurdles was sourcing a 12 string bridge as they aren't exactly an off the shelf item.  Modifying other bridges needs to include the octave strings being intonated separate to the bass strings.  One way to get round it is to buy a donor 12 string bass... Oh wait!    

[NancyJohnson]

1 hour ago, warwickhunt said:

I looked at converting a bass to 12 and the neck size, rigidity aside, the cost of parts started to stack up.  One of the big hurdles was sourcing a 12 string bridge as they aren't exactly an off the shelf item.  Modifying other bridges needs to include the octave strings being intonated separate to the bass strings.  One way to get round it is to buy a donor 12 string bass... Oh wait!    

 

Schaller used to make an eight string bridge; these seem to be easy enough to find - this would allow for intonating the two octaves:

 

 

The Konig Bassworx bridge is quite elegant:

 

[warwickhunt]

'Easy' to find... you sure?

[NancyJohnson]

26 minutes ago, warwickhunt said:

'Easy' to find... you sure?

 

Yup.

 

By easy, I don't mean Amazon Prime delivery, but if you search you'll find.

[Sean]

ETS will do one. It’ll be around EUR300.

These are what Brooks Bass uses. Also, the nut width on the Dean Rhapsody 12 I had was 54mm and that was a challenge for my medium (Size 9) hands. That 7 string at 62mm would be something else. The Hamer I have is 48mm and is very comfortable, it’s just 2mm up from my Spector Euro5. 

https://ets-hardware.com/index.php/de/

Edited 3 hours ago by Sean

[velvetkevorkian]

21 minutes ago, Sean said:

ETS will do one. It’ll be around EUR300.

These are what Brooks Bass uses. Also, the nut width on the Dean Rhapsody 12 I had was 54mm and that was a challenge for my medium (Size 9) hands. That 7 string at 62mm would be something else. The Hamer I have is 48mm and is very comfortable, it’s just 2mm up from my Spector Euro5. 

https://ets-hardware.com/index.php/de/

This was my thought. It tapers wider away from the nut too so you'd likely end up with a lot of dead space to either side using a standard 12-string bridge.