Strings for Garrison OM-20

[Cliff Seruntine]

I have a Garrison OM-20 that was made in 2007. Before me, it was owned by a collector who owns over a hundred instruments and either was never used or almost never used. It was literally without so much as a scratch when I acquired it and looked like it had just been unboxed. It was also kept in its case under low tension in a humidified room. So, it's in extremely good shape. It has the famous carbon fiber frame, and the soundbody is a flat top.

Its scale is 20.5 inches.

I have it strung with d'Addario EJ80 OM strings, but I find the GG and the DD a little muddy. Workable: I just have to strum a little lighter. I've been reading around the forum whatever I could find on this instrument and string choices, and a lot of persons recommend mandola strings for this scale length. I thought about it and calculated the string tensions. Mandola strings average a bit under 10% more tension pounds than OM strings, give or take a few percent depending on string type. I am not worried about the increased tension on the frame as carbon fiber is absurdly strong, but with the OM being a flat top, I worry about top sinkage over time if I increase the string tension.

Does anyone have a knowledgeable opinion on whether this increased tension is safe for the Garrison OM? Garrison is gone more than a decade, long since bought out and shut down by Gibson, and I can find no information from the manufacturer .

[OneChordTrick]

Not sure what the sizes of the EJ80s are? My OM has effectively the same scale (20.4”) and I use the manufacturer recommended strings which are .014/.022w/.032w/.045w. I think that these equate to the D’Addario Mandola set?

Doesn’t help as to whether it’s safe or not though....

[Cliff Seruntine]

That's almost exactly the size of the EJ80 strings from d'Addario. Good to know.

I have toyed with the idea of trying some lighter strings on the GG and DD. Tenor guitars use .042 for the Irish G tuning. I know it runs contrary to the typical directions for experiments but I have read here and there that flat tops can get by with lighter tension. Next string change, I'll put them on and see how they sound.

Thanks for your input.