So, I bought this bare bowl off another OFC member sometime last year and stashed it away into the someday pile.

It looks like that day has arrived. I guess I'll be doing four guitars at once, not just three.

I recently acquired a 1537 neck that is in pretty good condition. It's been played a lot, but otherwise it hasn't been abused.

I've been goofing around with moody p.i.'s 1537. I borrowed his 87C for a couple of weeks so I could satisfy my curiosity of how they sound since both of these guitars are rated among Ovation's best by quite a few people. For the most part, I like how both of these guitars sound, but truth be told, my ear has become accustomed to the sound of torrefied wood tops.

I originally planned to use the 1537 neck on an Elite version of the wood bowl Ovation I'm planning to build. But, I didn't want to wait that long to hear how a torrefied Quintad brace pattern sounded.

So, to coin a model airplane phrase, I decided to bash together a torrefied Quintad-braced Elite using the 1778T bowl and the 1537 neck. It's not going to be a permanent joining, just together long enough to hear how it sounds.

The heel is a little long for this bowl, but for this purpose, it will work fine.

If all goes well, these two necks will form the basis of two torrefied-top, wood-bowl Ovation guitars -- a Custom Legend and a 1537 Elite.

I took a photo of the Adamas braces from the Ovation Tribute site and imported it into CAD. I opened up the back of the 1537 and took some measurements of the braces, then drew them up.

I printed them at full-size, then spray-glued the templates to some 1/8" balsa sheet and cut them out.

I compared them to the braces in the 1537 and fine-tuned the profiles. Even though the test templates above are angled, the final templates will be rounded. It was easier to cut these out with an Xacto and a ruler than to hand-cut with all the curves.

Next job is to kit out the braces on all four guitars: 1528, 1612, 1117 and now, the 1778T(orrified).

Because this will be a torrefied wood top, I'm going to try to use a cross-grain piece of torrefied Sitka spruce sanded to either 1/32" or 3/64" thick  in place of the non-torrefied birch ply. Well, that is, if the guy I use can sand wood that thin.

The birch ply would definitely be stronger, but it also won't resonate like the torrefied spruce.

I was able to joint the top in preparation for joining and rough cut the braces.

I'm planning to join the tops for all four guitars at the same time so that I can take them down to the sanders and have them all thickness sanded together.

While each top is drying I'll be cutting out the braces. Top for the 1778T is being joined.

Referring back to the photo of the upper bout on the inside of the 1537, there is a cross-grain reinforcement. It looks to me like 1/32" birch plywood.

I'm not real keen on using birch plywood for this job, first because it's plywood and secondly because it's not torrefied. One of the main reasons why I use torrefied braces on the inside of the torrefied tops is so the braces have the same rate of expansion/contraction with changes in humidity. Using non-torrefied wood would change this. Unlike non-torrefied wood, torrefied wood doesn't really absorb moisture from the air. The second and most important reason is because the braces will of the same 'age' as the top, so they'll both have the same response. IOW, both are already 'broken in'.

So, my solution, or at least my first attempt at a solution, was to cut out 1" wide, 1/32" thick slices of the uncut torrefied brace stock.

The uncut brace stock is normally quartersawn. I was originally going to use another top, which is quartersawn, sanded down to 1/32" thick for this reinforcement. It occurred to me that quartersawn wood sanded that thin would be prone to cracking and splitting along the grain and would provide almost no reinforcement.

By cutting with the grain instead of across it would yield thin wood that is, essentially, flatsawn. IOW, thin, flexible, strong and not prone to splitting. Here's a drawing that shows the differences between quartersawn and flatsawn.

These will get glued edge-to-edge to form a thin sheet, which will get laminated to the underside of the upper bout. Then, I'll drill the sound holes.

I'm going to cut all of these to length, then laminate the scrap to a scrap piece of top wood. Once the glue has dried, I'll try drilling holes and see how it works. if the 1/32" reinforcements are too weak, then I'll cut new ones that are a little thicker, then try the drilling test again.

The outline of the top has been rough cut and the bridge alignment pin holes drilled.

The cross-grain strips are being laminated to the underside of the top. These will need to dry for a day. Once the glue is dry, I'll sand them smooth, then drill the epaulet holes.

This guitar will not be getting the epaulet leaves. Since this is a test piece, it'll be simplified for expediency.

Once the holes are drilled, I'll glue the braces into place.

Hi Jon,

Thanks for the kind words and you're welcome.

You could be right. I've never seen anything like it. Of the limited number of Elites I've seen, they either have the full width cross-grain plywood (1537) or individual pieces overlaid on the back of the holes outside the braces. (1768-7LTD, 2078TX-5)

Dan

Before attempting to drill holes in the top, I decided to mock up a couple of test pieces from the sound holes cut from the other tops.

I knew I needed several different sizes of drill bits to make the holes, the largest being 1-5/8", next largest 1-1/8", followed by a 1/2" and finally 3/8". I checked with Harbor Freight and they had a Forstner bit set which contained all these sizes for $38.

Here's the sample piece with most of the holes. The spacing between the 1-5/8" and 1-1/8" hole in this piece is only about 1/16", but the cross-grain doubler is doing a good job of keeping the sound board from splitting even when the holes are this closely spaced from each other.

The spacing on these two holes got closer because I made several attempts at the 1-5/8" hold and the drill bit wandered a little. When I do the sound board for real, I'll make sure to drill the hole(s) in one shot.

Next job is to mark the locations of the sound holes on the top and drill them out

I got the sound holes drilled. They aren't as perfect as what the MS could do, but for my purposes they'll work just fine.

Next job is to lay out and glue down the braces.

Braces glued down. I can say 'never again' will I use the full-width cross-grain. Taking a 1/32" notch out of the underside of the braces was a major PITA. I even had to re-do one of the braces. It would have been much easier to not have to do that. And, there's no real benefit as the only purpose of the cross-grain is to keep the webs between the holes from splitting out.

I can see why the factory did away with this and went to small patches over the sound holes.

Because the upper ends of the braces are so tall, I decided to make a jig to keep them more or less square while the gobars are clamping them in place. The main thing is to keep them from flopping over to the side.

I'll let these dry 24 hours, then pull the top out of the gobar deck.

Next job is to start gluing the tops to the bowls.

Very clean. Waiting with bated breath to hear your results. Be interesting to hear Beal's memories of the original process. After all, you are reverse engineering here.

Maybe they began using fiberglass in those areas and found it varied in thickness too much to make bracing fabrication a bigger PITA than using uniform plywood.

Anyway, carry on, Dan. Looking great.

Cutaway vs Non-Cutaway: Does it affect the sound?

Unless the volume of the body is increased on the cutaway guitar, it will have a tone that emphesizes the mid- to -high range. (Helmholtz resonance)

Since most deep-bowl Ovation guitars utilize the same basic molded bowl, the one with a cutaway will have decreased volume that causes a shift in the tone. The full-body will have a deeper, more rounded (no pun intended) tone.

Naturally, there are other factors that affect tone, including sound hole size, sound board thickness, brace pattern, etc. But, for two otherwise identical guitars, such as our Ovations, the one with more body volume will have a deeper, more rounded tone.

The Adamas got it's sound hole locations for two reasons: Increased stiffness between the bridge and the neck. This allows for lighter braces because they don't have to keep the sound board from distorting due to the center hole. The lighter braces allow the sound board to flex more which increases volume. (amplitude)

One of the reasons why one guitar might sound better than an otherwise identical guitar has a lot to do with the wood, itself. When my daughter was shopping for a guitar we tried two Epiphones that were the same model, same finish, both brand new. One sounded better than the other and that's the one I recommended she buy.

WRT appearance, you and I are in complete agreement. A full-body guitar looks better. :D

Top being glued.

Yes, that's the 1612 next to it.

Once the glue on all the tops is cured, I'll grind off the excess in preparation for routing the binding and purfling channels.

Sooo...

Getting back to this project...

I glued the purfling and binding to the body.

Tape is off and it's ready for scraping.

Purfling and binding is leveled to the top and the bridge is masked.

The rest of the masking is in place and ready for finishing.

First coats of the finish are on. Now, it's time for spraying and sanding, spraying and sanding, etc...

The actual rosette itself is an injection-molded plastic part that has the oak leaf pattern printed/silk-screened on the underside. The area where the pattern is located is inside a recess.

The pearloid/abalanoid or in the older Custom Legends, abalone sections, are glued into this recess.

Given how they're made, it would be pretty insanely difficult to create a rosette without the tooling.

You could have one created out of white and black MOP pieces by one of the many inlay specialists, but then the cost would be insanely high.

In a word, no, it's not practical. Speaking of impractical rosettes, I've always loved this one, which was on a prototype nylon-string Adamas.

The Frankenvation is all done.

So, I'm sure the next question on everyone's mind is "how does it sound?".

In a word, spectacular. It's everything one would expect from a quintad-braced Elite on steroids.

It's my new favorite brace pattern in torrefied spruce. It's got the balance of the A-brace with the brightness and sparkle of the X-brace.

Because it's a mid-depth bowl, I tried the PB extra light Elixir strings. It sounded nice, but was a little muted with no brightness at all. I restrung it with 80/20 extra light Elixirs and the guitar came alive.

I'll make a video in a day or so and post it to youtube.

Interestingly, I had the original bridge for the 1778T, but I didn't have a saddle/pick-up. So, I bought a graphtech saddle and a chi-com pick-up. Because of the compensation built into the saddle and the angle of the saddle slot in the bridge, the guitar has perfect intonation on all six strings.

It's the only Ovation acoustic I've played that has perfect pitch and I can say I like it and I'm definitely going to duplicate this set-up in the future.

Now that this project is done, I can move onto a couple of really interesting jobs. Stay tuned.

This guitar is an experiment so I could hear how a quintad-braced O sounds with torrefied wood. Eventually, I'll use this neck for my wood-bowl Elite and have to find another neck to go onto this guitar. I'll make sure that neck is a medium-bowl neck so it'll fit properly. Because I knew this neck wasn't more-or-less permanently mounted to this guitar, I did not glue the fretboard extension down. This means the guitar really can't be played above the 14th fret, which is not a problem for me.

Then, once i have the proper neck, I'll paint the bowl, either black or brown, depending on the neck I acquire.

Y'all have waited long enough.

Here's a youTube video of Paul 'Moofy' playing one of my most favorite songs on this guitar.

https://www.youtube.com/watch?v=rxWzV4nt9VE