String set for acoustic 7-string

[tbeltrans]

Yesterday, I purchased an Emerald X20-7 carbon fiber 7 string acoustic guitar from a friend of mine. I looked around the internet and couldn't find 7 string sets for acoustic guitar. There are plenty of choices for solid body electric, archtop, and classical guitars.

Since I have plenty of string sets for my acoustic guitars (D'Addario EJ-16), I am going to try a .059 phosphor bronze D'Addario string as the seventh string. If that is too light, I will try either a .062 or .064.

The strings currently on the guitar are John Pearse 12 - 53 and 068 for the seventh string, installed by the previous owner.

I am currently tuning the seventh string to A and plan to continue doing that. This guitar has fan frets and the scale length for the seventh string is 27" (25 1/2" for the high E string).

This evening, I tried tuning the whole thing down a whole step (A E A D G B E to G D G C F A D) and the strings became much easier to play (since I am used to my archtop with light gauge strings) and the guitar sound just bloomed, nice and full and warm (for a carbon fiber instrument).

Maybe just adding a single string to a 6 string set might be the way to go (I could purchase a bunch of single seventh strings and be set for a long time), but I would be curious as to what others here who have 7 string acoustic guitars do.

I am using this guitar to play solo chord melody and seem to be taking to having that seventh string easier than I thought I would.

Tony

[jazzshrink]

I haven't tried them, but perhaps these are worth looking at:

Pyramid Acoustic Guitar 7-String Phosphor Bronze #331 100 (.011 - .060)

[nevershouldhavesoldit]

Maybe just adding a single string to a 6 string set might be the way to go (I could purchase a bunch of single seventh strings and be set for a long time),

That's what I've always done. You can get Pearse PB RW singles from 0.068 to 0.080 to use as 7ths under Pearse PB RW sets. I keep a few of each size, although I'm down to one 7 string flattop now and do not want or need another. I put a used set of TI JS112s on it a few weeks ago when I switched to 113s on one of my achtops, and I like them enough to be thinking about using them regularly on the flattop. If I do, I'll go with the largest Chrome single I can fit through the tuner hole. I only have a stock of Chrome 65s and 75s, so I'll have to order a few in other sizes if I go to flats and can't get a 75 through the tuner on the flattop.

I have a few Sperzel tuners with oversize posts and holes for the 7th string, and I currently have them on 2 solid bodies. I've hesitated to put them on my archtops because they won't match. Sperzel also uses proprietary mounting pins on the bottom of the tuner bodies, so they won't cover the screw holes from the stock tuners. I've been able to get 75 Chromes in the stock tuners on both of my Eastman archtops with a little drilling. And I've tried unsuccessfully for years to get Ibanez to sell me a few of the oversized 7th tuners they put on AF207s. I'd put one of those on each Eastman

Most 7 strings in my experience come with standard tuners for all 7, although a few enlightened makers put a tuner with a larger post and hole at the 7th spot. So it's not possible to put anything larger than a 68 or 70 on most production 7 string guitars. I've drilled the holes in standard tuners enough to get a 72 in. It takes a steady hand, a solid and firm support for the tuner, and the right drill. Until we moved from our house to an apartment, I had a full shop and used a good drill press with a vise on the table. Now I use a handheld industrial rotary tool with the tuner held firmly between nylon jaws on my bench vise. You can't enlarge the holes much without weakening the post, so I usually only enlarge the hole by a few thousandths and stop when the remaining wall thickness on each side of the hole is visibly thinner than it is on the rest of the tuners. And you have to cleanly round / chamfer the edges to prevent string breakage where they enter the hole.

[Woody Sound]

And you have to cleanly round / chamfer the edges to prevent string breakage where they enter the hole.

How do you do that?

[tbeltrans]

Thanks for the info, nevershouldhavesoldit. The holes on my tuners are standard size too. I think I will try the D'Addario when my single strings arrive and it becomes time to change strings. Currently, there are John Pearse strings on it and I do like those just fine. So if I don't care for the D'Addario strings on this guitar, I will go back to the John Pearse. You have certainly validated using a 6 string set with a single 7th string.

I would think any chamfering would have to either be done with a hand tool or a VERY slow drill and carefully. Any nicks remaining around the hole or on the post would probably cause premature string breakage.

The 7 string is really working out for chord melody. I am catching on much faster than I had imagined.

Thanks,

Tony

[nevershouldhavesoldit]

I would think any chamfering would have to either be done with a hand tool or a VERY slow drill and carefully. Any nicks remaining around the hole or on the post would probably cause premature string breakage.

Quite right. I use a very fine diamond tipped chamfering bit in a good rotary tool with a very light touch and fairly high speed (5000 to 8000 rpm). It only take a brief touch to smooth the post holes, so I don’t lubricate it.

The other thing I’ve done on posts thick enough to do it safely is to shape a small, gently curved ramp at the spot on each side of the hole against which the string lies on its way to the nut. I use a very fine diamond barrel burr that’s only a tiny bit larger in diameter than the string, starting with the tip about 1/3 of the way through the hole, almost axial with it and just shy of contacting the inner wall. Start the tool (I use a foot switch), gently pull the burr against the wall, and drop the hand piece back as you withdraw the burr in a smooth motion to gently round the very shallow channel you’re making through the outer edge. Be careful not to hit the opposite side of the hole as you maneuver the tip out at an increasing angle. And make sure you’re withdrawing it from the second it touches the wall. If you let it remain still and gouge the wall, it will further weaken the post.

I use fine rubber wheels to finish the work. Since we only do all this for the largest string, the above is more than enough to prevent breakage, in my experience. I’ve been playing only 7s for about 30 years, and I had serious enough intonation problems on a few guitars early on to return them. So I’ve had a fair amount of experience with this. I met John Pearse at a Philadelphia Guitar Show not that long after I went to 7s, and he told me about using heavier strings.

[tbeltrans]

I haven't tried them, but perhaps these are worth looking at:

Pyramid Acoustic Guitar 7-String Phosphor Bronze #331 100 (.011 - .060)

Thanks jazzshrink. That set would also be worth a try especially with the lighter gauges.

Tony

[nevershouldhavesoldit]

Thanks jazzshrink. That set would also be worth a try especially with the lighter gauges. Tony

Some 7s won't intonate well with a "slinky 60". With Emerald's 27" scale at the 7, you may be OK with it - you'll just have to try it. I bought the first 7 string Ibanez flattop when it came out about 20 years ago - it was a nice natural, solid spruce topped jumbo. The intonation was terrible, no matter what I tried, and I returned it within a few days. But they came out with another one in 2014 (AEL-207E) with the same scale length (25 1/2"). It's made beautifully and has perfect intonation. It came with a D'A 12-70 set and I love it to death! It's my only flattop now and a true keeper.

[tbeltrans]

Some 7s won't intonate well with a "slinky 60". With Emerald's 27" scale at the 7, you may be OK with it - you'll just have to try it. I bought the first 7 string Ibanez flattop when it came out about 20 years ago - it was a nice natural, solid spruce topped jumbo. The intonation was terrible, no matter what I tried, and I returned it within a few days. But they came out with another one in 2014 (AEL-207E) with the same scale length (25 1/2"). It's made beautifully and has perfect intonation. It came with a D'A 12-70 set and I love it to death! It's my only flattop now and a true keeper.

Thanks. I ordered a couple of sets of the Pyramid strings that jazzshrink posted and will see if they work out OK. I suspect that ultimately, I will end up using the single D'Addario seventh string with the 6 string EJ-16 sets. I did ordered .064 and .070 single string packs and will try those too. When I settle on what works best for me, I will stock up. I should have enough to experiment with when all these arrive.

The Emerald is a surprisingly decent guitar - sounds very good, plays in tune, has a wider string spacing than I typically see on 7 string guitars which is great for playing fingerstyle, and it is light weight. The 7 string electric and archtop guitars I have seen all have narrower string spacing which I didn't care for. I can leave it out all the time since it is made entirely of carbon fiber and therefore environmental issues won't affect it. It has a nice hard shell Hiscox case if I ever want to take the guitar anywhere.

Tony