Drop A tuning and fret buzz on JP15 7 string

[Makesexnotwar]

Hello!

I have JP15 7 string for few years by now. It's simply one of the best guitars I've ever owned and played and I used to keep it in B standard(10-56 gauge) since I've bought it.
In general I'm more used to drop tunings. Occasionally I used to drop low B to A just for fun but I've never been satisfied with the feel of loose 56 string 7 string in A + of course there is an issue with intonation.

So I've decided to tune it to drop A properly. According to some string tension calculator on the internet I've decided to put 64 gauge as a 7th string and keep the rest 6 as 10-46 so setup in general is pretty standard. Also if I'm not mistaken JP uses 64 gauge for A tuning so looks like I can't go wrong with this choice. However I've ran in unexpected issue with string buzz. When I fret 7th string on 2-5 frets I can hear some weird harmonic which sounds like string touches few frets above. I've tried 62, 60 gauges but there is not much difference besides looser tension and intonation issues. I've tried to go with higher action but it didn't make any difference.

I suspected that it could be an issue with fret levelling so I took this guitar to the local luthier. It was a nice guy who made a scan with PLEK machine to find out if there is any issue with the guitar but after scanning turns out that all frets are fine. He thinks that may be guitar has specific resonance that only occurs for this tuning.

To be honest I don't know what to think at this point. I want to keep in in drop A but I can't get rid of this noise. I've recorded small clip to illustrate this issue.

noise-demo.wav

drive.google.com

There are 3 parts: palm mutes on open 7th string, simple groove that with fast mutes and similar groove that let notes on 2, 3 and 5 frets ring a bit more. In 3rd part you can clearly hear that buzz that I'm talking about. With current setup I have 64 gauge on 7th string and 1.5mm action. Truss rod setup is fine - neck has tiny relief.

What do you think can be the source of such buzz and how can I fix it? And what is your experience with drop A on JPs?

 

[Warmart]

Generally drop-A is going to need a 62 or 64 sized 7th string. Downtuning from B to A makes the 7th wobblier/looser, which makes it much more susceptible to buzzing.

 

[DrKev]

If you raise the action on that string to 1.75 mm does the noise still happen? Sometimes we just need more string height. Petrucci likes his action super low, like 1.25 mm, crazy low, and string buzz and noises are part of a tradeoff he's willing to make to get action super.

 

[Makesexnotwar]

If you raise the action on that string to 1.75 mm does the noise still happen? Sometimes we just need more string height. Petrucci likes his action super low, like 1.25 mm, crazy low, and string buzz and noises are part of a tradeoff he's willing to make to get action super.

I've tried it before taking guitar to luthier but I think I went with 2mm maximum but the noise was still there. I haven't tried it when I brought it back home but on the other hand this guy only did scanning, minor truss rod adjustment and filed nut slot so larger string won't get stuck. I'll try it again this weekend again.

Also I'm not sure if it worth to mention but I removed spring on saddle to be able to pull saddle as far as I can for better intonation. I'm not sure if this fact may have any effect on buzz.

Is it a good idea to try out large gauges like 68 for example? When I'm thinking about this it just feels too large for A but on the other hand it's 25.5 scale and I never had similar issues on any baritones.

Can it also be a kind of microphonic effect on a pickup? Or maybe something vibrates in control cavity? Tremolo springs are dampened of course

 

[DrKev]

I've tried it before taking guitar to luthier but I think I went with 2mm maximum but the noise was still there. I haven't tried it when I brought it back home but on the other hand this guy only did scanning, minor truss rod adjustment and filed nut slot so larger string won't get stuck. I'll try it again this weekend again.

Yes, do. Just go up in 1/4 turn increments on both saddle height screws until it stops or gets too high for comfort. How's your neck relief? Do you have a measurement or is it just some/none. A little more (loosen truss rod a little) might help. Keep track of every measurement you make and test before making another. And if you adjust something makes something worse, just undo the last adjustment.

Saddle spring will have zero effect here. A pickup mounting spring might do something like that at high gain, but your pickups are direct mounted to the body and don't have a spring, right?

I really think your instinct is right, it's probably a string noise. Going up a gauge may or may not help but it won't hurt to try.

 

[Makesexnotwar]

I haven't done any modifications to the guitar. Pickups shouldn't have any springs because of the direct mount however I've no idea if there is something underneath the pickups that keeps them away from the body so you could adjust height a bit. Maybe it's worth to unscrew it an see how they install pickups

Relief looks fine. I'm checking it by fretting string on 1st and 24th frets and the gap between string and 12 fret look like it a thickness of the business card. I think loosing it will affect other strings not i a good way.

I guess there are not much options besides playing with string gauge, action and truss rod. But is it worth to check frets in more old school way other then PLEK scan?

 

[Makesexnotwar]

Btw, how common is it to have problems like this on JPs?

 

[73h Nils]

If you DID go higher in gauge, I suspect you would also need to slightly file out the nut slot AND tuning peg. I had to really pull with pliers to get a 64 through the tuning peg the first time.

I had weird resonance a few times but I’m not sure it was ever across several frets. Maybe 1-2.

 

[Makesexnotwar]

If you DID go higher in gauge, I suspect you would also need to slightly file out the nut slot AND tuning peg. I had to really pull with pliers to get a 64 through the tuning peg the first time.

I had weird resonance a few times but I’m not sure it was ever across several frets. Maybe 1-2.

Filing the nut slot would be the next step after fixing the noise. For now it doesn't look necessary. I can easily fit 64 in tuning peg without any issues. I don't think there will be a need to enlarge it