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Don Noon

D. Noon's bench - Jackson Project

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I have my IR temperature measuring gun to check for dangerously high surface temperatures.  So far, the cool ocean breeze has kept it below 85F (29C).  The slab of marble is to keep the cool ocean breeze from blowing everything off the table.

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On this wood, the nitrite appears to have taken some color out, darkened it slightly, and increased the contrast of the flames.  It's all moderate, nothing dramatic.  Somewhat like using photoshop to decrease brightness, decrease color saturation, and increase contrast.  Slightly. 

 

The ground brought the color back.  Here's the sequence of white, nitrite, ground. 

post-25192-0-03372500-1372219373_thumb.jpg

Color varnish tomorrow.

 

I will not antique this one.

I will not antique this one.

I will not antique this one.

I will not antique this one.

I will not antique this one.

I will not antique this one.

 

 

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Mostly terpene resin.  I like the color it gives on wood.  First a few coats of thin terpene/solvent, then a couple of thinly applied coats of a terpene varnish, thinned with sovent and re-thickened  with fumed silica (to about pancake mix consistency) to get a barrier layer.

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Mostly terpene resin.  I like the color it gives on wood.  First a few coats of thin terpene/solvent, then a couple of thinly applied coats of a terpene varnish, thinned with sovent and re-thickened  with fumed silica (to about pancake mix consistency) to get a barrier layer.

I agree and like the look of turpene resin in the ground. Since I used up all my turpene resin I now use this product which is similar in that it contains no oil just Silver fir resin in turpentine...I got the idea from Ben C. It comes in thick or thin.

http://www.kremerpigments.com/shopus/index.php?cat=0604〈=ENG&product=79282

 

 

Edit- I just looked at the MSDS and Rosin Oil is:

Burgundy Resin  50-55%

Silver Fir Turpentine 40-45% 

Larch Turpentine  5%

Turpentine Resin Oil is made by cooking colophony, and dissolving it in hot spirits of gum turpentine.

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Maybe a little bit antique wouldn't harm :)

 

From past experience, yes, it will.

Knowing a little more about what's necessary to do a decent antiquing job, I'll put off that project for some other time.

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From past experience, yes, it will.

Knowing a little more about what's necessary to do a decent antiquing job, I'll put off that project for some other time.

Quite right, Don. At the Varnish Workshop, Roman Barnas, Benjamin Ruth, and Marilyn Wallin discussed antiquing techniques. Doing a decent antiquing job is not easy. I will never try it for sure. Why should I ruin a perfectly mediocre violin? (LOL)

Mike

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Varnishing is going along at about maximum speed, now that the sun has really gotten serious.  Surface temperature of the fiddle gets to 145F or so.  The solar broiler doesn't really make it any hotter, as the reflected sun doesn't hit the surface directly facing the sun; it just gets sun on the normally shadowed sides.  Varnish at night, overnight in the lightbox, then bake in the sun during the day.

 

After the second color coat (transparent iron oxide and glisonite), the iron oxide really took over and it was starting to get blindingly bright red/orange.  A coat or two of browner varnish will hopefully tone it down to something more reasonable.

 

While the varnish dries, I have time to work on the fingerboard.  55.4g currently, a little more will get taken off during final action and scoop adjustment.  The narrow slots shaved off 3 - 4 g.  I used to make a single cutout, but I think there was some slight flattening of the radius during final clamping.  The center ridge should prevent that. (edit: now 54.5g after narrowing the center ridge to 3mm wide from the 5mm shown in the photo).

 

post-25192-0-73612500-1372557330_thumb.jpg

 

Even with these kinds of lightweighting tricks, it looks like I'll be 5 or 6 grams heavier than the Jackson, which was measured at 371g without chinrest.

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I'll call the varnish done.

Here's the back sequence; it appears that the color is getting lighter in some of the later shots, but I think the camera was just automatically adjusting the exposure.

post-25192-0-45164700-1372740257_thumb.jpg

I'm fairly happy with the "luminescence", as Joe calls it.  The fiddle actually looks dark to me, until you shine a light on it.

post-25192-0-81601500-1372740253_thumb.jpgpost-25192-0-33664100-1372740255_thumb.jpg

And I'm trying the black chamfer deal, since this is a Strad model and I'm not antiquing it.

post-25192-0-48547100-1372740252_thumb.jpg

 

A few more baking days in the sun, then I'll polish it up and do all the rest of the stuff.

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Looks great, I like the black on the edges of the scroll. I'm also done with antiquing. I want my next one to look like the Messiah, for that I have to study varnishing a little bit more. I'm also done with cooking wood for the moment UV is better.

 

Hope this violin will sound (almost) as good as my #5  :)

 

You have probably posted this somewhere, but is your varnish home made or a commercial product?

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 is your varnish home made or a commercial product?

Mostly my own cooked up stuff.  The base varnish in my red color coats has some commercial varnish in it... I took all my little bottles of stuff (commercial and my own) and cooked them down into a big batch of mystery varnish that I couldn't possibly repeat. 

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Varnish Completeish and Assembledsortof

 

I won't post any new photos, as it doesn't look any better than before, with temporary junk fittings.  The idea is to get it together and play it, then do the final setup work and polishing in a month or so when everything has stabilized and I have a better chance to adjust it in the right direction.

 

I don't know if I spelled out the 3 main reasons for trying to copy the Jackson, but they are:

1.  Exceptionally strong and broad "bridge/body hill", extending down well below 2 kHz.

2.  Phenominally strong acoustic output from the CBR resonance, giving a huge-sounding D string in 1st position

3.  Relatively modest, peak-free "transition hill" range

 

Did copying arching and graduations magically produce the same results????  Mostly, no... but overall the result seems to be tonally in the right direction.

 

Impact response, white and varnished.

post-25192-0-65575900-1373217922_thumb.jpg

The change from white to varnished is more that I have observed in most of my other ones, and I have no explanation.  The harshness of the white fiddle seems to be gone; perhaps it was the big bump at ~8000 Hz, and/or some of the power in the 1000-1500Hz range that was the problem.

 

1.  The bridge/body hill DOES seem to be quite broad and strong, which seems to give very good projection to the E string.  I believe the combination of high arching, stiff wood, and thin graduations (particularly in the upper bout) is mostly responsible.

2.  The CBR strength is still a complete mystery.  Copying arching and graduations didn't do it, and I have no hope of finding a magic adjustment to make it show up.  The difference is so huge, and it's in a frequency range that is insensitive to adjustments.

post-25192-0-45961900-1373217921_thumb.jpg

(In consideration of the value of the Strad, I did not give it my normal beating to get an impact spectrum, but used a very light tap from a vinyl-tipped "hammer".  I used the same hammer to get a close comparison from my copy.)

3.  There's still the peak or two in the 900 - 1000 Hz range in my copy that is more subdued in the Strad.  This might be adjustable to some degree, but I don't think it will get down to the level of evenness of the Strad, at least in my lifetime.

 

One other point related to item 3:  in playing I found that the resonance made for a nasal sound I don't care for on the A string (A# and B, 1st position) and also an octave below that on the G string.  However, on recordings, it wasn't obvious.  That led me to check the response spectrum at the player's ear position:

post-25192-0-31337400-1373217920_thumb.jpg

It is immediately obvious that the 900-1000Hz peak is far stronger at the player's ear than elsewhere.  Not so obvous, but also of great importance is the fact that the fundamental of the objectionable notes is also several dB weaker at the player position than elsewhere.  That adds up to a 10+dB skewing of the fundamental/overtone balance at the player's ear compared to the full field.

 

In plain English, some notes sound bad when you play them, but the audience hears something much nicer.

 

Anyway, I'd say the bottom line is extremely good, especially for less than 24 hours after string-up, even though it doesn't sound exactly like the Strad.  I'll post photos when I get the final fittings on, and hopefully post sound clips of a shootout with the real thing.

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Here is a string-by-string semitone scale comparison, with the Strad first in each pairing.

Keep in mind that this is a 300 year old multimillion dollar instrument vs. a new one strung up for about 12 hours, and recorded in different rooms.

Yes, there are differences... the main one I hear is the voluminous G and D strings on the Strad, no doubt in my mind mostly from that mysteriously powerful CBR resonance.  A and E strings sound similar to me, but what do I know.  Well, I DO know that differences show up most strongly when really capable violinists push them to the limits in a large hall, but this ain't it (yet).

Strad vs 14 scale comparison.mp3

 

 

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Here is a string-by-string semitone scale comparison, with the Strad first in each pairing.

Keep in mind that this is a 300 year old multimillion dollar instrument vs. a new one strung up for about 12 hours, and recorded in different rooms.

Yes, there are differences... the main one I hear is the voluminous G and D strings on the Strad, no doubt in my mind mostly from that mysteriously powerful CBR resonance.  A and E strings sound similar to me, but what do I know.  Well, I DO know that differences show up most strongly when really capable violinists push them to the limits in a large hall, but this ain't it (yet).

attachicon.gifStrad vs 14 scale comparison.mp3

 

Surprisingly similar. Incredibly so. Great stuff, Don !

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I'm pretty close to the Jackson thicknesses (as measured by Sam Z, by way of Anders Buen):

attachicon.gifStradivari_1714_back_graduations.jpg

 

It's quite thin, which is why I used maple with moderate density and high stiffness.  It also has broad, light figure, which likely contributes to the longitudinal stiffness of this particular set.

 

The arching is also very high, at 16.5mm.  The Jackson may 1 mm lower, but my rib height will be 1 mm less, so I increased the back arch.  Not an exact copy.

I noticed that these plate thicknesses on this Jackson Strad are even thinner than those for the 1715 Titian on my Strad poster.  On my last violin, I thinned it's plates basically to the Titian thicknesses, which was the thinnest that I have ever cut my plates, and it has a decent tone with the low end finally starting to sound sort of like I want.  I'm thinking that thick plates = student sound, so I need to thin them for better tone.  Thinning them so much that they collapse or that the violin sounds hollow is something that I want to avoid.  Do you think that if I thin the top and back plates to these Jackson thicknesses that my violin will still be structurally sound and have a chance at a decent tone?

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A lot depends on the wood and arching. Since the graduations were frighteningly thin, I used medium-dense, extremely stiff wood to (hopefully) withstand the static stress. I also would think that high arching allows going to thinner graduations without becoming tonally tubby. For sure these thicknesses would be a disaster if you had low arching and low density wood.

For the idea that "thick plates = student sound", you may encounter some opposing views on that. Vieuxtemps and Cannone supposedly sound pretty OK. I have tried initially leaving my plates thicker than usual, but so far didn't like the result and ended up regraduating them. I may yet try again, with a Vieuxtemps-inspired version, which doesn't really look excessively thick to me.

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I also would think that high arching allows going to thinner graduations without becoming tonally tubby. For sure these thicknesses would be a disaster if you had low arching and low density wood.

Hi Don, I'm not quite following the logic here.  Maybe you can help my caffeine deprived mind understand the concept.  In my mind a high arch means the distance (along the arch) is longer, so there would be more flexibility (less stiffness) for a given thickness compared to a more shallow arch.  Kind of like a longer bridge (for cars not violins) needs more support.  Or is it that the shape of the arch gives more support/stiffness that allows for thinner graduations?

 

-Jim

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post-25192-0-88326900-1373377676_thumb.png

Arching to resist a vertical force is far more efficient by using compressive stiffness instead of bending stiffness, as you can see in most bridges. If flat was stiffer, you wouldn't have that arch above the roadway holding it up.

It's a little more complicated when applied to vibrating surfaces (well, more like a LOT more complicated), but the general idea of increased stiffness holds. In my experience, the arching stiffness has the most effect on the middle frequencies, where response is lessened for the higher arch. At the higher frequencies, the response appears to be unaffected, or possibly slightly enhanced by higher arching. The net effect is that higher arching sounds brighter, all else being equal (which it never is).

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Just some more detail, in numbers, from this comparison. Signature mode frequencies:

Mode____Strad_____ #14

A0_______268_______274

CBR ___384/423___377/406 (double peaks, measured separately, not from graph)

B1-______432_______433

B1+______549 ______553

Again, there was absolutely no "tuning" of the plates... I only used dimensions. I did monitor weight and taptones as I went along, just in case anything looked dangerous, but it didn't, so I just went to the final dimensions.

Two things:

1. A0 of mine is modestly higher than the Strad. This is a pattern I think I have seen: old violins have A0 frequencies lower than new ones, all else being equal (as far as I know). I don't know why that should be. You could hypothesize that the body gets more flexible with age, but then the other modes should be lower, too, unless the wood density is lower on the old ones.

2. By using the same dimensions and obtaining the same frequencies, one can conclude that the wood is similar in some ways... with one caveat. Weight. My best estimate is that my copy is ~10g heavier than the Strad. Excluding fittings and fingerboard, I figure ~4% lower density wood should account for it. This is not unreasonable, as I selected rather high density wood for this project. 4% lower would mean .39 density for the top and .59 density for the back. Well within normal range... and still on the high side.

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