Red diamond mandolin

[guitarpath]

Interesting. What is the difference between the Replica Series and the Vintage Series?

[Mike Bunting]

Interesting. What is the difference between the Replica Series and the Vintage Series?

Go to the website and all will be explained.

[guitarpath]

The Red Diamond website is down, Mike. I would not ask here if the info was readily available online. When it was up earlier this summer, no specifics were offered as to the differences between the Replica and Vintage Series.

My Vintage '22 has a red spruce top, was made with hide glue, and was built using Grisman's Crusher as a template. I wonder how this would differ from the Replica Crushers that Don made.

[Mike Bunting]

If I remember correctly, the Vintage is based on the averaged measurements (Don has a way of measuring top flex too) of several Loars while the Replicas are as exact as possible according to the measurements of specific instruments e.g. the 1922 Grisman "Crusher" Loar. Don will build the Vintage using the voicing that he uses on the Replica model, hence the Vintage 22.

[guitarpath]

Thank you, Mike.

[V70416]

It's not only measuring thicknesses;but Don MacRostie was the first maker I ever knew who started measuring flex of tops and backs. I saw him flex a mando while at his shop in the mid '90's. Had no idea what it all meant. Still don't. The device he used had a sort of micrometer face to read amount of flex.
Maybe it is a common way to measure tops and backs. IDK?

I have Red Diamond F5 #61 with the falling-leaf headstock inlays. It has been everywhere with me for a lot of years. Refreted once,it now sports an aluminum bridge saddle. Years ago I had the Fla. cut off the end of the fretboard at the 19th. fret. Will Kimble refinished it in black-top(my favorite top color)and fixed a small crack at the bottom end of the treble F-hole. The mando is 26 years old and still sounds and plays just right.

#61 spent its formative playing years in New Mexico and Telluride,Co. at lots of festivals and firesides. That may help explain the top crack I mentioned. This mandolin has been in Georgia for about 20 years now and it gets played almost everyday. Due for another refret soon.

[sblock]

The tone produced by a mandolin top depends on MANY properties, not just the thickness graduations. It depends on the type and location of any bracing. It depends on the finish properties. It depends on the shape. It depends on the distribution AND the values of the density, stiffness, and damping of the particular tonewood used. That's a whole lot to consider! Copying the bracing pattern, shape, and finish of a Loar-signed Gibson is no guarantee of the tone, and NEITHER is copying the exact thickness graduations, as well, because these interact seriously with the local stiffness, density, and damping -- all of which vary from one type of wood to another, and even from one specimen to the next.

Therefore:

You cannot copy the tone by simply copying the thickness graduations, because each bit of tonewood is a bit different in density, stiffness, and damping. Stiffer wood needs to be thinner to flex the same amount.

Measuring the actual flexure of a top is a better way to get at its stiffness than simply copying the thickness graduations.

But even doing that does not control for differences in wood density and damping! Here, you might just have to go by experience and take your best guess. You could also try to measure the density (not so hard) and the damping (harder!).

You can try tap tuning, but that looks at the resonant frequencies of modes, which depend in complex ways on shape (a lot), density (a lot), damping (but only to a small extent), and stiffness (a lot), and not on individual values of these, which you'd need to match to truly capture the identical tone.

There is no easy answer. For now, the best guide is an experienced ear -- and luthier -- guided roughly by some (not all) parameters that they have come to trust. Deflection tuning is as valid as the next technique, and probably at least as good, and arguably better, than tap tuning. And both of those methods probably beat simply copying the graduations.

[fscotte]

Don seems to have had difficulty in measuring the back. He said he's still looking for ways to improve the rigidity of his jig, after 40 years.

[drbluegrass]

I owned a RD Vintage 22 David Grisman "Crusher" voiced mandolin. RD mandolins are everything the OP and others say. Outstanding in every aspect. I got the fever to teach myself Scruggs style banjo. In order to purchase a banjo the RD had to go. I have a great sounding Harvey signed Gibson F5G. But I'll have a RD to go with it someday.