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Building a Jumbo - Need Advice Please
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Author:  BruceH [ Wed Nov 23, 2005 9:00 pm ]
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I'm starting my next guitar and need some advice. It's going to be played by my nephew who plays praise/worship stuff - strumming with a thin pick and fingerstyle. He likes the J-200 shape with a cutaway, so that's what it will be. It will have a 17" lower bout and cuban mahogany b/s.

On to the questions:

I'm concerned that a body this big will lend itself to muddy bass or boominess. Any advice to keep this from happening? I'm thinking about building a thiner body like John Greven does with his Prairie State - say 4" max depth. Maybe also use a slightly thicker top?

I've got the choice of WR cedar or Luzi spruce for the top. I'm thinking that the mahogany/cedar combo will be sweet for fingerstyle, but may fall apart under brisk strumming? What do you guys think?

Thanks.
Author:  Dave White [ Wed Nov 23, 2005 11:25 pm ]
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Hi Bruce,

Personally I love the combination of European spruce and Cuban Mahogany and have made a number of guitars with this combination. The biggest I have made (apart from a baritone) was a small jumbo'ish large OM'ish guitar with a 16" lower bout width and max depth of 4 7/8" and this was really nice for fingerstyle, pick and strumming. I find that Cuban mahogany has lots of "Rosewoodish" tendencies and will give you good string balance with good trebles and bottom end. Here's a pic of it with it's happy owner Mark Williams in North Carolina:



My vote would be for a nice Carpathian spruce top (which is a form of Euro spruce with a good following in the US). I haven't built with it but according to Tim McKnight who has a lot it responds well to fingerstyle and has the pick/strumming headroom. Again I haven't built with it, but I suspect that the WRC wouldn't cope as well with the strumming - this is what the original Lowden O series guitars used and it wasn't a guitar with a great "strumming" reputation (although some people loved it).

Going narrower body will be fine I think and you could also take the basic J200 shape and adapt it for say a 16.25-16.5" lower bout width. Keeping the top a little thicker than usual will help with the mids/trebles and then thinning it out around the sides/back of the lower bout. Dave White38680.3111574074
Author:  Brock Poling [ Wed Nov 23, 2005 11:49 pm ]
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The J200 has a bad reputation as an awful sounding guitar. If he is not 100% sold on that body, you might look at the Gibson Advanced jumbo. That by contrast has a very good reputation and is a very big guitar. (and personally, I think that is a good looking guitar too)

Something worth considering.
Author:  Bobc [ Wed Nov 23, 2005 11:51 pm ]
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Bruce here's one that I did exactly that. Jumbo 17" body with OM thickness. The redwood top is a bit boomy but still quite nice. I tend to agree with Dave on the carpathian top.
Author:  tippie53 [ Thu Nov 24, 2005 12:16 am ]
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Cedar may not be the top for this. I agree with the Carpathian spruce . ALso the shape of the braces and the layout is critical
john hall
Author:  Pwoolson [ Thu Nov 24, 2005 12:32 am ]
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Cedar tends to be warmer which might be confused with muddieness on this guitar. I'd stick with the brightest top you can. Carpathian or sitka will both be good choices.
Author:  Colin S [ Thu Nov 24, 2005 1:25 am ]
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Mahogany and WRC (or redwood) is a classic combination for the fingerpicker, but the WRC lacks headroom and would lose definition and become dull when pushed with a pick (sorry had to sit down as I just used the dreaded word).

I agree with Dave and the rest that a European spruce top would give the best balance. I'm still to be convinced that the "Carpathian Spruce" cultivar of P. abies is any different to any other good samples, but perhaps that just reflects the Euro spruce that reaches the USA.

If the balance of play leans towards the pick (there I said it again!),although I never use it myself, Sitka might be the best choice or maybe a Lutz, I believe Bob C keeps it.

Colin
Author:  BruceH [ Thu Nov 24, 2005 2:14 am ]
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Thanks for the input, guys. You've confirmed my suspicions the cedar is not the way to go on this. I've got an assortment of Engelmann/sitka/Lutz tops and some are very stiff. I'll sort through the stack and pick a stiff one. I'm footing the bill so I want to use what I have.

I think that I'll squeeze the lower bout to 16.5 and keep the depth down as originally planned.

Bob - Nice looking guitar. Walnut? How does it feel when sitting? Does the narrow depth give the impression of holding a smaller guitar?

Dave - Nice work too. I personally like that shape much better than the jumbo. Is that soundhole larger than the usual 100mm?

Brock - I've read that J-200 aren't the greatest either. I tried to convince him that something else would be better, but you couldn't tell me anything when I was 19 either    So now I'm looking at it as a challenge.

Paul and John - Any bracing ideas? I'm thinking that I'll need a double x to keep this big top in line.

Thanks!
Author:  John How [ Thu Nov 24, 2005 3:11 am ]
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Bruce, it has been my experience that double x braces are stinky, some others may have different experience. My double x was a flying arrangement so I was able to remove half without interfering with the other. That opened the guitar right up and alls well that ends well as they say. But I probably won't do another double x. Gibson discovered the same thing back in the 70's.
Author:  Bobc [ Thu Nov 24, 2005 3:31 am ]
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Bruce it does feel very comfortable with the thinner body. The b/s are black walnut. I don't play with a pick and it is very responsive to finger picking. Now as for the J-200 I made one in curly maple for a friend of mine who has been playing for at least 30 years. He claims it's the best guitar he ever owned. Go figure. Maybe it's because Gibson didn't build it.
Author:  Pwoolson [ Thu Nov 24, 2005 3:54 am ]
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Bruce, I do nothing but double x tops. They are actually quad x braced as the lower x crosses the upper x. For me, they are very successful. I'm not sure why when so many people have had negative experiences with them.
Author:  Dave White [ Thu Nov 24, 2005 5:38 am ]
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Bruce,

Yes - the soundhole is 110mm diameter. Works really nicely with the design I have that has a narrow X brace angle, the soundhole towards the neck and a domed top (the braces are shaped on the bottom to a 15' radius but the shape of the top is not spherical). I use pretty much the same bracing pattern irrespective of the top size. The guitar in the picture has my version of the double X brace but with the lower X having one arm broken and shifted slightly. I haven't used the locked X brace Paul does, but I have read Alun Carruth posting of using this method to good effect. Here's a pic of the top bracing for Mark William's guitar:



Of your two choices I'd probably go for the Lutz unless you have experience of Englemann on bigger tops - I've read that it is great for fingerstyle but maybe not for the "big strum". But hey what do I know - I've not built with either and it's my pet hate to read statements made on things without experience. Just slapped my own wrist
Author:  Tim McKnight [ Thu Nov 24, 2005 11:39 am ]
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Bruce:
I build my Jumbo's on the J-200 platform only with forward shifted X and wider [more open] X angle]. I have two in process now [both are for worship leaders]. One is a heavy attack player and his is EIRW/Adi, the other player is a lighter player / fingerstyle and his is EIRW/1959 Sitka.

I have built a few Mahogany/Adi Jumbos and this is a good combo for power and bass response [if the top is thinned appropriately].

I have not built any Jumbo's with Carpathian yet so I have no feedback for you. Lutz has more flex than Sitka so it may be a good choice as well as Engleman. If he will ever be attacking the guitar hard (as some worship leaders tend to do without realizing it] then Sitka may be a better choice.

Carpathian that I have measured is actually the stiffest tone wood that I have tested [yes stiffer than Adi]. It is responsive to a light touch but also has some headroom but not as much as Adi or Sitka. It tends to be articulate, very clear and can even be a bit bright sounding.

The J-200 body style is very balanced and not boomy or bass heavy at all and that is why I like it. It doesn't have that Martin-esque thump. It makes a great guitar to record or plug in.
Author:  BruceH [ Thu Nov 24, 2005 1:38 pm ]
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Dave - Thanks for the bracing pic. It's always interesting to see how much bracing patterns differ from builder to builder, yet still works.

Tim - Thanks for the info. What are the body dimensions for your model? Around the web, I've seen the body depth listed as anywhere from 4.5 to 5 inches.
Author:  Tim McKnight [ Fri Nov 25, 2005 8:50 am ]
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Steve: Here you go -
http://mcknightguitars.com/products.html
Author:  BruceH [ Fri Nov 25, 2005 9:53 am ]
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Thanks, Tim.

BTW, who's Steve?
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