Official Luthiers Forum!

Hello everyone,

This being my first post, I'd like to provide a little background. I've been active at projectguitar.com since the early part of this year, and have been working on an electric guitar since May. It was an excellent learning project, but it's going on the backburner now so I can build the guitar I really want to build. It's not strictly an acoustic, but I have been repeatedly referred to the experts here for advice, , so I humbly submit my work.

I hope it's ok to post this here, as it's really a hybrid. I'd be appreciative if some of you would be willing to share from your experience what in this design might work and might not - where my thinking is correct, and where I'm still ignorant.

Much of the details are evident in the design. It will be a laminate bolt-on neck with a dual-action truss rod (I already have one lying around) and carbon fiber rods for support. The body will consist of a Sitka Spruce braced top over a 3" thick hollowed-out electric body, where the sides will be (I think) around 3/8"-1/2" thick. The back will be around 1/2" thick (I think). I haven't made a decision there yet, and would welcome suggestions. I plan on using hybrid strings, like the DR Zebras. I have to do some testing to figure out what I like.

There are two "part-time" sound holes integrated into two separate control cavities, as shown. This will allow me to experiment some with location, shape and size of those holes even after the build is complete. It will also allow me to close them off completely to help with feedback issues when they arise. The cavity covers will be held on with strong magnets.

I plan on using two Seymour Duncan P-Rail pickups for electric sounds, and I'm leaning toward the K&K Pure Western Mini pickup for acoustic sounds. All I care about is what it will sound like plugged in.

You'll notice also that I've added what will be a 1/4" block of mahogany under the electric pickups to help reduce feedback. I got the idea from Rick Turner's guitars.

What do you think? How well would you anticipate it will function as an acoustic (plugged in)? What changes might you suggest? Thank you in advance for your kind support and advice. I'm very new to this, and it's all so complicated that I feel a little lost.



-Dave

P.S. Oh yeah. Wood is TBA. I might pick something up tomorrow though!

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David Morris

Interesting...

I'm no expert on electro-acoustic hybrids, but if you want an "acoustic" sound, don't you need a soundhole ("F" holes or round) in the front of the guitar somewhere (to complete the Helmholz resonator)? Having holes in the back will surely produce variable tone depending on how the player is holding the guitar, right?

Also, you're planning to start with a 3" (at least) thick chunk of wood and hollow it out for the back/sides?
Isn't this a tremendous "waste" of wood, not to mention a lot of work? Surely it'd be easier, much cheaper, and more green of you to make it in the acoustic fashion, with separate back and sides?

What do our experts think?

Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Hi Dave and welcome to the OLF!

I'm clueless about what you want to do but I wanted to welcome you just the same.

Great to have you here and nice job on the illustration of your guitar.

Hey Dave,
Interesting design... don't forget that you have to ground the strings, which is not the easiest thing to do with an acoustic-type bridge.
Also, it is not clear to me how you are going to integrate the 1/4'' block of mahogany with the top braces.

Marc

If you aren't concerned about how the guitar sounds when unplugged you can just cut one or more F-holes on the top, it would make the guitar look good. Also, you might want to bend the side and you can use a large block of wood in the middle for the pickup and stuff, also for neck attachment and you shouldn't need bracing.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Thank you all for your input and your warm greetings.

Dave F - I've been thinking the Helmholz resonance. When Taylor when developing the T5, their prototype had a sound hole on the back. According to them, it worked the same as having it on the front. I have a version of this design with a sound hole on the front, but I don't love it. And I like the idea of being able to tune in the right sound by switching out those plates. As for bending the sides, I go back and forth on the idea, and I think both concepts have merits. Do you have any specific idea of what contribution these thicker back and sides will make to the sound?

Marc - Great point about the grounding! I hadn't thought about that yet. I'll have to do some research and figure out what others have done. As for the bracing, I was thinking I'd notch out the bottom of the brace to allow for the mahogany block (which is only 1/4" thick).

-Dave

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David Morris

Sounds like it will be heavy.

There is no need to ground strings for safety; it's for lower noise.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

If anything ungrounded strings are safer, no possibly way for a ground leak/dangerous currents to travel to you. However your guitar will be very noisy.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Welcome Dave! Your guitar idea sounds nice.Prs makes a hollowbody like yours except it has a thicker top with f holes.They hollow out the back and sides from solid wood too.As for grounding, you should because it will be noisy otherwise.If you use a prs style bridge,you can ground to that from your pots.Or mabey a brass bridge nut with a ground will work.Just an idea. Good luck with your build and keep us informed on your great idea! Mark

Thanks Mark!

Yes, the plan is to ground the strings. I was probably unclear in my last post. I meant I'll have to do some research and figure out how others have accomplished grounding strings with an acoustic bridge.

And yep, it'll be heavy compared to an acoustic guitar. It will be lighter than most electric guitars too.

I failed to addressed the question of wood that Dave posed earlier. I'll be building a body blank from several pieces of wood. I'll stack 8/4 and 4/4 wood. I may use several 8/4 pieces of around 6" each, and for the middle part, just use two pieces - one at each end. Like a picture frame. I don't know if that makes sense. Anyway, that would be better not only for the environment, but also for my pocketbook.

Thanks for all your suggestions.

-Dave

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David Morris