Intonation on my FP

[Vai the god of Sound]

The intonation on my jem is a little off. I'm tuned a full step down and I had set my intonation several times to make sure it's in tune...but it can be in tune on one part of the new, and out of tune on the other...

I mainly have this problem with the first three strings FAD (Which in standard tuning is GBE)

The open strings can be perfectly in tune, but if I play a certain chord...1 or 2 strings will be slightly out of tune. I realise that a guitar cannot be perfectly intune without some sort of buzz feiten system or fret manipulation, but is there any trick that can overcome this?

[Rich]

Set the intonation at the 24th fret

[Vai the god of Sound]

thats what I usually do...hit an open harmonic at the 12th fret, and compare the tuning at the 24th fret (fretted)

[Rich]

Hopefully the open string is in tune first

[MicJustMic]

Try blocking the trem when intonating. Cut some wood to fit both behind and in front of the trem block to keep it balanced in the center position (the position you have it set for normal tuning).

As you change the position of the saddle(s) you change the tension and this can cause the bridge, at full tune, to go up and down a bit in balance.

So, you intonate the sixth string perfectly, then intonate all the other perfectly, and some of the strings end up off as the bridge goes up and down a bit.

True, this shouldn't be a big difference, but if you have to move all of your saddles back, or forward quite a bit it can really change the angle of the bridge to the point that you'll have to adjust the screws to compensate, thus changing your intonation slightly.

With the bridge blocked in a neutral position, all you have to worry about is setting the intonation, and when all six/seven strings are all set, you take out the blocks and adjust the claw to bring everything back to "center".

Just a thought,
Mic