30-string Contra-Alto update, part 1

Note: I started this draft blog entry on October 14, 2024.  It remained in a draft status until now, as there were other things happening with the 30-string. 

I spent most of the day yesterday, October 13, 2024, working on the 30.  

• Swapped out the locking Grover tuners on the 12 side for non-locking Grovers.
• Did a tiny bit of work on the nut slots for the 2nd course on the 18 side.
• Shaved the saddle on the 12 side.
• Re-shimmed the 18's treble bridge saddle, lowering it by .005.  Made a welcome difference in the action, but the first two courses were fretting out at 1 and 2.  Increased the gauges on those four strings by .001 on each, and that solved it.  Unsure about the change in tone on the heavier gauges, but am still learning it after all the changes yesterday.
• New strings on 12 side.
• Changed the 12 side's tuning/gauges from D to C bari.

The 30 is kind of hard for me to understand in terms of action.  The action on the 12 side is just above 1/32, which is perfect, but it feels higher.  I keep measuring it, and of course it's not changing, but I feel like the measurement is lying to me or something.  Maybe it's the short scale.  Maybe I need to re-slot the nut.  Maybe both.  

 

The action on the 18 side is around 1.5/32".  I'd like it to be lower, but I'm wondering if I've hit the limit on it.  The neck geometry is exactly right with no relief.  I can't get the saddle any lower on the treble side (treble = first 5 courses) without fretting-out issues.  It doesn't need fret work that I can see, as the stainless-steel frets still show zero wear after me playing it intensely for about 13 years.  It could need a fret level, as that would explain the action limitations and fretting-out.   I may take it over to my luthier friend north of me.  Have him look at it and see what he says.  If a fret level is required, I'll certainly have him do that.  

The gauges and tuning on the 18 side are perfect and have been for quite a long while.  At least, in the current tuning and register.   

 

The gauges and tuning on the 12 side are still very much a moving target.  The gauges I put together for the C bari tuning are too light.  They work, but would work better if everything was a bit heavier.  It sounds and feels a bit spongy.  I put together a set of C bari strings ranging from .050 to .012.  A stock 12 E concert set is .047 to .010.  I have a few sets of Pearse's new heavy-gauge 12 sets which runs .056 to .013.  I'm thinking that is likely the way to go for C tuning.  Assuming I want to leave it in C, and I'm not sure.  It speaks and responds perfectly well in that tuning.  I guess I could try the heavy-gauge set and drop it into B and see what happens.  I'm slightly amazed that a 24" scale can work as a bari, but then again, it is carbon fiber.

 

More to come.

-kk