Bridge compensation specifications

[daikon]

I am just finishing up a one-piece ebony bridge, based on the Red Henry design, for my Sucek 2-point mandolin. Even without the final compensation and notching, the bridge sounds excellent.

I am wondering if anyone knows the proper compensation offsets for J-74 strings on a standard scale length.

I could just copy what was on the origigal bridge, but thought I would check here first to see if someone has found the ideal formula.

Thanks.

Mike Novak (Daikon)

[sunburst]

I find that every mandolin and every set of strings seem to be a little different. I haven't found a magic number.
I compensate each bridge saddle for each mandolin with a file and a strobe tuner.

I start with the bridge positioned so that no string is flat when fretted, and file the front edge of the saddle selectively 'til all the strings note true at the 12th fret.
Actually, I think it's more important that the strings note true somewhere around the 7th through 9th frets, and if that's not the case, I might compromise the 12th fret note to get the others closer.

[Darryl Wolfe]

Sunburst....I'm impressed. That's pretty meticulous

[daikon]

Sunburst:

Thanks.

That makes intuitive sense.

Unfortunately, all I have is an electronic tuner and pickup. It gives pretty stable readings with the pickup and gives readings with a precision +/- one cent. However, precision does not always equal accuracy.

However, I'll try your method with this equipment and see how it turns out.

Mike

[Luthier Vandross]

The Buzz Feiten tuning system is expensive, and completely worthy of every dime, if you haven't heard it, consider yourself in the middle ages!

Serious, if not somewhat off-topic.. sorry.


M

[Gavin Baird]

Hey "M"
You're just a endless scource of information.. serious and on topic..."Grin"

[Chris Baird]

Be careful that you break the strings in that you are going to use to fine tune the compensation as new strings will require a big change in compensation after a few days of playing. I've messed up a saddle by cutting the compensation in with new strings. The compensation was way off after a few days.

[daikon]

Mandoplyr:

Thanks for the advice regarding new strings. I'll get a new set on for a few days before compensating the bridge.

Now I just hope that I don't overcompensate; I've been told that I do that. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

Mike

[Dolamon]

If you haven't downloaded this already take a look (http://www.kennaquhair.com/)at Doug Dieter's site.

On the bottom of the left hand menu is a link to download his marvelous Universal String Tension Calculator. This little program has three functions if you explore it: String Tension 2/ Fret placement and 3/ Bridge Compensation offset. The instructions are pretty minimal but is easy to work all of the functions and ... they all are useful. The advise regarding adjusting - and testing - intonation is sooo true.

[Michael Lewis]

That string calculator is a neat thing, but it doesn't take into consideration the different proportions of core wire to wrap wire you are likely to encounter if you use a different brand than the "calculator" was programmed for. #For example, a larger core wire is stiffer than a smaller core wire, and the bulk of the string gauge is made up with the wrap wire. #A stiffer string needs more compensation than a more flexible string. #Is that sufficiently obscure?

The calculator gives a general starting point for intonation, you will have to refine your saddle to suit the strings you choose.