Distance from bridge to pole pieces (P90) Gibson ES125

**TPMCD** · 12-31-2022, 06:09 PM

OK, this is an odd question, but maybe not too odd. Going to be putting a P90 pickup in my Harmony archtop (long story with this, but I simply can't find a floater that I like the looks of), and I'm trying to get a ballpark estimate of where I should put the pickup. Thought I'd start with a Gibson ES125 (also ES175 I suppose because the scale length is the same). The scale on the Harmony is 25", the ES125 is 24.75", so I know it's not going to be exact and it doesn't have to be. Just trying to get an idea.

So - to those of you that have an ES125 or ES175 with a single P90, could you give me the measurement from the bridge to the center of the pickup (the pole pieces) in inches?

Thanks, hope you're all doing well!

Tom

**sgosnell** · 01-01-2023, 11:15 AM

The usual way is to put the polepieces under the theoretical 24th fret. You can use the harmonic, or you can measure the distance from the nut to the 12th fret, then add half of that more. It works for any scale length. Marking the harmonic isn't easy, but it makes finding the location easy, and checking that the measurement was correct. This of course requires at least one string to be in place at pitch. Measurements don't need it.

**Sam Sherry** · 01-01-2023, 12:58 PM

1965 Gibson ES-125CD:

Originally Posted by TPMCD

. . . putting a P90 pickup in my Harmony archtop (. . . I simply can't find a floater that I like the looks of)

With all due respect, you may want to consider playing some guitars with set-in pickups and others with floating pickups before routing a hole in your guitar based on how it looks.

Originally Posted by sgosnell

The usual way is to put the polepieces under the theoretical 24th fret.

As shown, Gibson had the double-octave about 3/8" closer to the fingerboard than the pole-piece. (Or maybe they used the other 'usual Gibson way' -- eyeball it and ship it!)

**sgosnell** · 01-01-2023, 04:09 PM

I'm not sure that putting the 24th harmonic over the polepieces was ever really a thing, except for aficionados who seem to obsess over it. I've seen little evidence that factories ever were concerned with it. I've also found no real difference in tone with the pickup at different locations. I have some guitars with DeArmond Rhythm Chief pickups, on which the pickup can easily be moved in near infinite amounts from the end of the fretboard to the end of the rod, a couple of inches or more, and the difference between the extremes is minimal, with a very small increase in treble as the pickup is moved toward the bridge. But many people believe that the pickup should be under the 24th harmonic.

**ccroft** · 01-01-2023, 05:29 PM

I agree with sgosnell due to the simple fact that we tend to play fretted notes, which sends the 24th harmonic southward for the notes being played.

**TPMCD** · 01-01-2023, 05:38 PM

Originally Posted by Sam Sherry

1965 Gibson ES-125CD:
With all due respect, you may want to consider playing some guitars with set-in pickups and others with floating pickups before routing a hole in your guitar based on how it looks.
As shown, Gibson had the double-octave about 3/8" closer to the fingerboard than the pole-piece. (Or maybe they used the other 'usual Gibson way' -- eyeball it and ship it!)

This is great info; I agree that I should play some guitars before routing the hole, and your pic and explanation gives me better insight (meaning, it's not *always* at the 24th fret, etc.). Much appreciated.

Tom