Double Bass Kay neck overstand and angle

[Kai Sanchez]

Hello everyone,
A while ago I purchased a M1 Kay bass (S/N 55520) that came with its neck off. I would like to have my luthier increase the overstand and the angle. From reading a few threads here on talkbass I have learned that you can increase the overstand by adding wood at the heel bringing the neck forward. You also can increase the angle by adding a shim with a slight inclination between the fingerboard and the neck.
Someone told me that I should be careful about doing this on a Kay, that I should check the condition of the plys of the top and the bass bar, that the increase in tension could damage or worsen the condition of the bass (the bass looks good, but I'm not 100% about the condition of the plys and bass bar).
Any comments about this?
Thanks in advance!

BTW I checked this thread, great info:
http://www.talkbass.com/forum/f3/neck-standoff-height-55881/

 

[james condino]

No disrespect towards the individual intended, but.....if your "luthier" is does not have a good understanding of the geometry and setup of a double bass, then you should find someone else who knows what they are doing. It is not a funny looking guitar or an oversized fiddle; don't take it to a guitar shop or fiddle shop unless they understand AND enjoy working on old Kays......just look at the thread from last month where someone's "luthier" took a nice old American Standard and destroyed it in the name of restoration AND left them with a good sized bill to pay. ....

That said, old Kays generally have a factory overstand of approx. 1" or roughly 25mm; this results in a bridge height of 135-140mm which winds up being a bit low for arco (you'll be hitting the bow on the C bout area constantly) and the overall voice can be a little muddy and thumpy. This is not necessarily a bad thing; resetting the neck to original specs will maintain the classic Kay sound and be a plus with crusty old traditionalists. A more modern neck setup would be to increase the overstand to around 40mm and wind up with a bridge height 6 1/2-7" tall.

Serial number 55,xxx puts your bass approx. 1967. Late 60s models generally have "poplar" (southeastern US Tulip poplar, a magnolia family tree with nothing in common with European Lombardy poplar) inside plys. It tends to be softer than the earlier models that have maple plys on the inside layers and it is also a lot weaker, so the inner plys tend to delaminate VERY easy and the bassbars chronically come loose. Often it is not so much the bassbar coming loose as the ply that the bar is attached to rips apart from the inside of the top while still attached to the bassbar. Increasing the overstand / bridge height will increase the stress on the top and likely cause the bassbar / plys to eventually come loose. Whenever I change the geometry like this, I generally will also add cloth overlays to the ends of the bassbars to prevent them from coming loose and I also like the addition of a breastpatch around the soundpost area on the inside of approx. 0.120" red spruce. This stiffens the top in that area, giving it a little boost from the extra tension and gives a little bit more punch to the instrument.

In general, if it is my personal bass that is under restoration, about 60% of the time I'll make these modifications (along with a neck shim and carbon fiber inserts under the fingerboard) to come up with a total package that winds up being slightly louder, more "punchy" and has more sustain than an original spec factory setup- great for folks who want to stretch it out a bit and play a variety of music styles on one bass. I also understand that by doing so, I offend and rule out 50% of my other customers who are very staunch traditionalists and go out of their way to maintain that old school Kay sound.

In direct relation to the specific questions you asked, the spring and current issues of American Lutherie Magazine (www.luth.org) have a 20 page article series on vintage plywood bass restoration with a lot of images and information from my workshop in Tacoma last year. Before you spend any money at a shop, read both of those and get a copy of Chuck Traeger's book on bass restoration; they should set you up with enough information that you'll be comfortably able to make an informed decision on your own about how to proceed.

'Hope that helps; post some photos for the visual geeks and let us know how it goes.

j.

 

[bassfiddlesteve]

Excellent information. This kind of insight from pros is what makes talkbass great. I wish I knew all of this when I was having work done to my '49 Kay M-1.

- Steve

 

[Kai Sanchez]

WOW!!! Thanks for all this info James Condino, I wish I lived in Asheville, NC! The luthier that has my bass has done really good work on my carved bass, but I'm sure he's not a kay specialist. I think maybe with some direction he can pull it off! The repair is on stand by, so no hurries, maybe I'll just put it together as it was originally designed. But all this info is very interesting.
Thanks James.

 

[danceswithbass]

No disrespect towards the individual intended, but.....if your "luthier" is does not have a good understanding of the geometry and setup of a double bass, then you should find someone else who knows what they are doing. It is not a funny looking guitar or an oversized fiddle; don't take it to a guitar shop or fiddle shop unless they understand AND enjoy working on old Kays......just look at the thread from last month where someone's "luthier" took a nice old American Standard and destroyed it in the name of restoration AND left them with a good sized bill to pay. ....

That said, old Kays generally have a factory overstand of approx. 1" or roughly 25mm; this results in a bridge height of 135-140mm which winds up being a bit low for arco (you'll be hitting the bow on the C bout area constantly) and the overall voice can be a little muddy and thumpy. This is not necessarily a bad thing; resetting the neck to original specs will maintain the classic Kay sound and be a plus with crusty old traditionalists. A more modern neck setup would be to increase the overstand to around 40mm and wind up with a bridge height 6 1/2-7" tall.

Serial number 55,xxx puts your bass approx. 1967. Late 60s models generally have "poplar" (southeastern US Tulip poplar, a magnolia family tree with nothing in common with European Lombardy poplar) inside plys. It tends to be softer than the earlier models that have maple plys on the inside layers and it is also a lot weaker, so the inner plys tend to delaminate VERY easy and the bassbars chronically come loose. Often it is not so much the bassbar coming loose as the ply that the bar is attached to rips apart from the inside of the top while still attached to the bassbar. Increasing the overstand / bridge height will increase the stress on the top and likely cause the bassbar / plys to eventually come loose. Whenever I change the geometry like this, I generally will also add cloth overlays to the ends of the bassbars to prevent them from coming loose and I also like the addition of a breastpatch around the soundpost area on the inside of approx. 0.120" red spruce. This stiffens the top in that area, giving it a little boost from the extra tension and gives a little bit more punch to the instrument.

In general, if it is my personal bass that is under restoration, about 60% of the time I'll make these modifications (along with a neck shim and carbon fiber inserts under the fingerboard) to come up with a total package that winds up being slightly louder, more "punchy" and has more sustain than an original spec factory setup- great for folks who want to stretch it out a bit and play a variety of music styles on one bass. I also understand that by doing so, I offend and rule out 50% of my other customers who are very staunch traditionalists and go out of their way to maintain that old school Kay sound.

In direct relation to the specific questions you asked, the spring and current issues of American Lutherie Magazine (www.luth.org) have a 20 page article series on vintage plywood bass restoration with a lot of images and information from my workshop in Tacoma last year. Before you spend any money at a shop, read both of those and get a copy of Chuck Traeger's book on bass restoration; they should set you up with enough information that you'll be comfortably able to make an informed decision on your own about how to proceed.

'Hope that helps; post some photos for the visual geeks and let us know how it goes.

j.

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