What is the correct way of adjusting P90

[shortfuse]

What is a good starting point for Magnet to string distances. 
I have a guitar i recently purchased that has a dogeared Lollar in the neck and Fralin in the bridge. 
The clean tone is great and crunch tone is very good but the High gain tones are not good to me at all.  Not at all like my SG with P90's which has a big fat sound with high gain.  And by high gain I am talking JCM 800 kinda gain.
I am going to look tonight to see if I can get the model numbers off the pick ups.

[HotBluePlates]

The clean tone is great and crunch tone is very good but the High gain tones are not good to me at all.  Not at all like my SG with P90's which has a big fat sound with high gain.  

Well, how does the clean and crunch sound on your SG? Is it just that the pickups on the new guitar have different strengths, or maybe the guitar itself has a different sound?

What is a good starting point for Magnet to string distances.

Well, these are single-coils with strong magnets. Assuming you have your guitar intonated very well now, raise the bridge pickup quite high, play a chord around the 12th fret (which you found to be perfectly in-tune before) and lower the pickup until the warbling stops.

If the body of the pickup is closer to the strings, the volume and meat of the sound will increase. But if you lower the body of the pickup and raise the polepieces, treble and clarity will increase.

The only right position is the one that gets you the sound you want. When I worked at Gibson (a long time ago), we installed P-90's by eyeballing the approximate correct height. Maybe the final setup guys had a specific measurement they used for pickup height, but that would have been a compromise setting at best.


Oh yeah... I can't tell you if everyone does this, but Gibson used to place foam rubber under dogear pickups to allow some degree of adjustment. But there was always less adjustment than soapbar-style P-90s, which had 2 adjustment screws with springs.

[shortfuse]

Thank you HBP

That is what they did the dog ears were down in contact with the body.  But each pole piece was brought closer to the strings (way out of the cover) I assume to achieve the correct distance.  But in doing so it did make the treble increase a lot.  I turned them back down where they were about 1mm above the cover for a starting position and it sounds much better, fatter.  Still not as fat as the ones in the SG but they are different pickups.  I did not measure them last night I will measure the outputs of the pickups tonight.
Thanks again

[HotBluePlates]

With dog ear P-90's, if you want to raise the whole pickup rather than just the polepieces, you'll need some kind of shim underneath. Lollar (or other P-90 makers) may sell shims.

I always liked soapbar P-90's better, just because it's easier to adjust the height. But I know that you have to go with dog ear models in a hollowbody or semi-hollow guitar.

[G._Hoffman]

Yup.  For dogears, you shim them up until one of the E strings is right, then you adjust the other E string until it is balanced, and then adjust everything in between to match.  You do want to do the E strings first, so you hand an idea of how they compare. 


Gabriel

[shortfuse]

Thanks for the advice I do not think I will need shims. I lowered the poles back flush with the cover and adjusted the E's from there and then the others in between.  It sounds light years better now.  Still not quite like the LP but then again I was not looking to have to guitars with the same tone I am happy with it now.  These are from my point of view very touchy pick ups to adjust.   
Again thanks for the comments.
Steve

[HotBluePlates]

These are ... very touchy pick ups to adjust.

I only recently thought about this fact:

When you raise the adjustable pole pieces closer to the strings, what you are really doing is moving more magnetic material out of the "core" of the pickup. That lowers the inductance, and reduces lows (which is why we think of raising pole pieces to increase highs).

The P-90 is a wide, flat pickup without much depth. The bobbins on those aren't tall, so the wire winding spreads out further side-to-side. Compared to humbuckers, a little movement of the pole pieces probably tends to have a big impact on pickup inductance and therefore its overall tone.

All this dawned on me when I was looking at the TV Jones website, which lists pickup inductance, in addition to d.c. resistance. Because pickup geometry is not all the same (Gretsch-style Filtertrons are humbuckers, but a different height-width ratio than Gibson humbuckers), just having the same d.c. resistance doesn't guarantee the same sound. And TV Jones recommends against adjusting the pole piece heights in his pickups (at least initially), probably because they are set a certain way to give a particular inductance and a certain sound.

Anyway, glad you got your pickups set the way you like them.