Humbucker Setting Experience

[ChrisN]

I posted this issue on the Gear Page luthier section and thought some here might benefit from my experience. I think there are 3 guys on the TGP luthier's page.

Background - '93 LP Studio with too-harsh sound led me to conclusion I had a dropped coil on the bridge (sounded like a cheap push/pull coil split). Concluded that wasn't so, just a bad sound, so set out to fix it.

So, I did some more work on this. Due to the modest mid-7K DC impedance on both pickups, looks like I've got the 490R/490T set. I've used various methods of setting p/u height, pole piece height, etc., and some worked better than others. Before giving up on these pickups (especially the bridge with the harsh/thin high e string), I decided to give pickup setup another go. I used these two related videos (I've no affiliation):



I followed the instructions to the letter, even though some conflicted with prior info. The result was surprising - both pickups sounded as good as they ever have, but also they were now "even," producing their different respective tones at the same volume. I'd always had the bridge come up louder for some reason, probably because it was too close to the strings. Plus, my heroes always appear to play one or the other pickup, seldom/never on both, so you keep the lead tone/bridge louder, right?

But, while improved, I still wasn't knocked out by the pickups when played individually. The neck lacked the definition I wanted - a little thick/soft/fuzzy, and the bridge, while OK (full/sharp) on E-G, was too brittle/thin/harsh on B and e. That sound on the bridge is what made me think I had a broken coil wire. I'm a new player and had always played 2 pickup guitars on the individual pickups, and these were just not that great (I've got a nice MHS set in a 339 for "great" reference). I like clean, low-gain, articulate, like a strat or P90 approach, which is harder to get on a HB guitar. HOWEVER, when I played the bridge and neck together in the middle position, the guitar suddenly sounded perfect. It's as if the pickup set was meant to be played in the middle position.

When played together, the bridge sharpens up the neck and adds strength, while the neck softens the bridge, and gives it more body. The combined tonal range is sweetened/expanded beyond either pickup's individual capacity, and it's fun to surf back and forth between warm jazzy sounds and lead, to almost-Tele twang, just by working the volume and tone knobs. Quite an eye-opening experience.

Hope this keeps someone from wasting as much time on it as I did!

[ChrisN]

And to follow up my own post, I was pondering the "why" of the bridge pickup's harshness. I know the strings' amplitude (range of movement) at the bridge is greatly reduced from that above the neck pickup, so it makes sense the bridge pickup has to be stronger/hotter to make less amplitude sound strong, and to be closer to the neck pickup's output. Either that, or the bridge pickup has to be placed too close to the strings (creates separate issues).

Gibson makes the 490R/498T set that I think attempts to remedy the issue. The 490 runs in the 7.5k range, while the 498 is 13+k. That combination makes the bridge too strong relative to the neck, so many say the 490/498 is a mismatch that requires changes at the amp when switching and forth, to compensate.

The 490/490 set in my Studio, in contrast, places a weak bridge pickup at a point where string amplitude is greatly reduced, producing a weak signal that sounds, to me, like a dropped coil on B and e. It appears to me the 490 in the bridge wasn't intended to work like a typical lead bridge tone, but rather to work in tandem with the neck to function as reported in my post above.

I'm sure I'm wrong, but it makes sense to me that the 490/490 set is not intended to be as "rock oriented" as the 490/498 set, but is to serve as a more generalized, wider ranging pickup set. For reasons unclear, I've seen different sources say that either set came in these early-mid 90s Studios, but nowhere do I see one had a choice when purchasing. I did find an old print piece ("revised 9/92") that confirmed the 490/498 set for, at least, 1992. If mine came with that set, it may be that someone replaced my guitar's original 490/498 set with a 490/490 set, but I think that unlikely, given everything under the hood looked original, and the original gold pickup covers (a Studio option along with chrome) were used.

Anyway, that's my theory. All input appreciated.

[C-ville Brent]

I have a 2014 LP Studio with the 490R/490T set with original wiring set up (push/pull coil splitting tone pots). I know our guitars are several years apart and don't know if your guitar has the coil split feature. I tried the coil split when I first got it and found the sound similar to what you describe - thin. When in HB mode, both pick ups seem strong like a good humbucker should.

My thoughts are that you may have a coil-split going on with a stuck pot. You may want to check your control cavity. If the pu's have 4 conductors and 3 are going to switches or pots, you probably have coil splitting. If 2 of the 3 lead wires are connected to each other (i.e. black and white or red and white, DiMarzio and SD), you probably don't have coil splitting.

Many of my dilemmas have ended up with simple solutions after pulling my hair out looking for something more complicated. I hope things work out!

[Bob Womack]

I find that when I get the pickups properly aligned for level I need to back off the treble on the bridge pickup. That's all it takes. I've owned six dual-pickup Gibsons with the four-knob controls at this point and it has been true of all of them. Many have discovered this as well. Try it!

Bob

[ChrisN]

Originally Posted by C-ville Brent

I have a 2014 LP Studio with the 490R/490T set with original wiring set up (push/pull coil splitting tone pots). I know our guitars are several years apart and don't know if your guitar has the coil split feature. I tried the coil split when I first got it and found the sound similar to what you describe - thin. When in HB mode, both pick ups seem strong like a good humbucker should.

My thoughts are that you may have a coil-split going on with a stuck pot. You may want to check your control cavity. If the pu's have 4 conductors and 3 are going to switches or pots, you probably have coil splitting. If 2 of the 3 lead wires are connected to each other (i.e. black and white or red and white, DiMarzio and SD), you probably don't have coil splitting.

Many of my dilemmas have ended up with simple solutions after pulling my hair out looking for something more complicated. I hope things work out!

Your analysis is spot-on, but is N/A here as my Olden-Dayes '93 Studio has the ye olde 2 wire non-splittable pickups. I should have mentioned that I'd previously installed a full RS Guitars Modern kit that has high quality pots/caps (500k instead of 300k).

Re: Thin sound from split coil - I've read you can equalize the volume issue by splitting the bridge, put bridge volume on all the way, while keeping the neck volume more reduced. That way the transition's supposedly less noticeable. I tried it with an Epi split coil and didn't like it that way either. The way to go is with a boost pedal when going to the split coil - I haven't tried it, but it sounded great when I heard it done.

I've seen a trend lately away from full-split to partial split coil so the reduction in output is less pronounced. I understand PRS (core?) does a nice job with splitting coils, but don't know if that's how they do it.

Originally Posted by Bob Womack

I find that when I get the pickups properly aligned for level I need to back off the treble on the bridge pickup. That's all it takes. I've owned six dual-pickup Gibsons with the four-knob controls at this point and it has been true of all of them. Many have discovered this as well. Try it!

Bob

I stumbled onto that solution during the extensive A/B session trying to dialing in the pickups - I now keep the bridge tone on 3-5 (again, with the RS Guitars kit, which seems to offer a wider tonal range than OEM). I'm happy to hear you've apparently gone through the same thing with too trebly/thin/harsh high strings on the bridge pickup. I like having my papers graded by a pro!

I'm very happy with the guitar's sound, now.

[C-ville Brent]

I appreciate the feed back. I guess that's what we're all trying to do - help each other out if we can. I'm glad you've gotten a sound your happy with. Happy playing!