All profit supporting special needs music education and Help Musicians
Tutorials

SML Gold Medal Optimal Key Heights (an Overhaul in progress)

Feon

New Member
Messages
6
Locality
Sofia, Bulgaria
That's my first post here, hope I don't break a rule :D

I've got a very nice early SML GM2 in the Summer, which I decided to overhaul in the Christmas Holidays. It needed badly a repad and for dubious aesthetic reasons I decided to strip also the patinated nickel keys (it had the "two tone" finish).

I had ordered some months ago Chocolate Roo pads and TM resonators, had already tools, adjusting materials etc. This is my second overhaul, previously I have restored successfully a silver plated Grassi Export (I may upload some photos in the Media, when I get the needed credentials). Being my second sax I work on, and the first lacquered one, I made a huge screw-up by accidentally letting the water running too hot in the bath tub o_O. From what I've read I always thought nitrocellulose lacquer would hold moderately heating... But at about 51C I found that the precious 99% lacquer had started peeling away in nostalgic rosy flakes...

After the damage was done, I somehow adjusted to the nonpractical aesthetics of a bare brass horn :confused: and applied two coats of carnauba car wax, which I plan to replace by a better synthetic one.

The overhaul otherwise went fine, after stripping the keys I had to do only a very minor fitting, as the sax was in a pretty great shape mechanically with almost no movement between the posts. The tone holes needed slight levelling. I replaced the corks and felts with more silent and appropriate materials, also replaced the plastic pearls with natural ones.

This was also the smoothest repad I could imagine - as the cups were 95% parallel to the tone holes, I almost didn't need to float the pads to seat them (used shellack). The problem I had was rather with some pads being slightly thicker on one side, so I had to cut off some of the leather. It turns out Smls like the thinnest pads one can find.

Now, the reason I started this thread: Setting the optimal key heights.
I followed the MM's Balanced venting method guide. Although I had thinner corks as originally the sax came with, the keys needed to be opened substantially. I wonder how and why the sax felt quite well balanced and not muffled before the repad. The C cup needed to be open and the rest of the upper stack was set to the same height. The F cup of the lower stack also needed substantial opening, as the F# was rather muffled compared to the well vented tone holes. Same with the D - usually mid D sounded very full before the repad, but now compared to the other keys it was somehow stuffy, which made me set the low C key very open...

Now, I really need some help to optimize this, here are some questions, that I hope the experts here could help with:

  • Can anyone with a well adjusted SML tenor share his key heights? PM will be also fine, if this information is somehow considered not for wide public. SMLs are pretty consistent and I'm sure the info would be adequate.
  • Is there a better method for setting key heights? Is optimal venting the most important characteristic when setting key heights?
  • With a softer reed (Rigotti Jazz 2,5, played on a Francois Louis T285 mpc) the horn seems overly even, but with a bit harder reed (Rigotti 3 reed) the problematic tones (mid F#, mid D) stick out a bit and get a stuffy shade. I guess this would be due to embouchure support as well. :confused2:

Your imputes will be much appreciated! I'm adding some images.
Thanks :clapping:
Alexander

IMG_8501.jpeg
IMG_8432.jpeg
 

Chris J

Member
Messages
211
Locality
Southampton, UK
First obvious question has to be - are you absolutely 100% sure there are no leaks? Special attention needs to be to the pad cups that are indirectly activated by linkages, that the timing of simultaneous closure is perfect, and no leaks once closed.

Chris
 
OP
Feon

Feon

New Member
Messages
6
Locality
Sofia, Bulgaria
are you absolutely 100% sure there are no leaks
That is a good point! Yes, I believe there are no leaks. Of course that is an art I have just started comprehending. I seated the pads with a leak light to close evenly on the tone hole, with and without the spring. I have checked the seal in the course of 2-3 days and still plan to recheck with a cigarette paper as well, but there should be a pretty adequate seal.

I have to add that I checked many images of SMLs on the web, particularly those freshly overhauled (two on the Matt Stohrer's website), but the key heights, albeit also quite open, are rather difficult to be judged well.
 

Chris J

Member
Messages
211
Locality
Southampton, UK
Even if the pads close perfectly, the timing is still critical, and from what you mentioned in your description, I would certainly double check that when you press the F# key, the pad just above the lower stack that also closes, does so properly and simultaneously.

Chris
 
OP
Feon

Feon

New Member
Messages
6
Locality
Sofia, Bulgaria
I would certainly double check that when you press the F# key, the pad just above the lower stack that also closes, does so properly and simultaneously.
Yes, all the lower stack linked keys close properly and simultaneously. The linked bis key also does close properly.
 

Stephen Howard

Well-Known Member
Messages
1,873
Locality
UK
I seated the pads with a leak light to close evenly on the tone hole, with and without the spring
Absolutely no point in doing this. The geometry of the action changes when it's under tension due to play in the action and the flexing of the keywork.
 
OP
Feon

Feon

New Member
Messages
6
Locality
Sofia, Bulgaria
Absolutely no point in doing this. The geometry of the action changes when it's under tension due to play in the action and the flexing of the keywork.
Thanks for the input, I have read this tip in your book or elsewhere. It was a bad phrasing, as I didn't intend to go into the details in the repad part.

What I meant is the other way around - in the process of seating a pad upon putting the keys back, I first check it without the spring engaged and readjust if there are any bigger leaks, when it looks good, I add the spring tension and do a final seating.

I see that with the stack keys there is no much need of that effort, but on the spring-closed keys I do this in order to avoid making an initial impression on a not yet properly seated pad by the spring tension.
 

jbtsax

Well-Known Member
Subscriber
Messages
7,935
Locality
Beautiful Springville, Utah USA
Yamaha is the only manufacturer I know of that publishes recommended key heights. I have attached the pdf file below. My system is very simple. For the stack keys I set the key height of the F key to the Yamaha spec and all of the other stack keys heights are determined by that once lost motion is removed. I use that measurement as a starting point and may increase or decrease the opening slightly by filing cork on the key feet, or adding felt under the key feet (usually on the lower stack).

For the independent keys like the palm keys, side keys, low C and Eb, I set the opening to where the note speaks clearly. The opening of the bell keys and low C# are interrelated and determined largely by the adjustment of the LH table keys.
 

Attachments

OP
Feon

Feon

New Member
Messages
6
Locality
Sofia, Bulgaria
For the stack keys I set the key height of the F key to the Yamaha spec and all of the other stack keys heights are determined by that
Thanks, that is very useful! At the moment I'm about 1,5mm more than the Yamaha's recommendation.
Please check the attached photo if I take the measure at the correct place (at the widest opening, between the tone hole and the impression mark).

IMG_8596.jpg


The question is if the most vented, clearly speaking height should be the one to strive for, or there is a point to go slightly lesser than that in order to balance the register. :confused2:

In an older thread about SMLs Jazzaferri mentions to play them, it will be great if he can chime in with some measurements. :thanks2:
 

jbtsax

Well-Known Member
Subscriber
Messages
7,935
Locality
Beautiful Springville, Utah USA
It is a bit difficult to get an accurate measurement with conventional digital calipers. A trick I learned is to determine the opening using a T-Bore Gauge and measure the width of the tool with a caliper, You touch one end to the tonehole and the other to the impression in the pad keeping the tool as perpendicular as possible.
 
Saxholder Pro

Members OnlineStatistics

Help!Mailing List
Top Bottom
test6