Hi Scott
Send an email to Customer Support Europe and got a reply from California in a couple of hours which was impressive. They said NOT to fit the medium gauge string set as it could cause damage to the bridge and top with the extra tension at concert pitch. At my very limited playing skills I really enjoy trying to play along to songs on the CD player which is why I want to stay at concert pitch so I guess I'll stick to the lights unless anyone can suggest any other option for a slightly warmer sound. Thanks for the advice, that could have been a disastrous exercise.
Regards Bob
I understand the desire to keep things at concert pitch. FWIW, I had a lovely 655 that benefitted wonderfully (IMHO) from tuning down a full step (to D) with the elixir medium-gauge set (to which the factory said was perfectly fine tuned to D). To my fingers, it felt the same in tension, but the sound was deeper and mellower than tuned normally with lights. Capo 2 and you're right on pitch (and may I personally recommend for a 12-er to get the G7th Performance capo for 12s). Totally easy and sounds great whether or not you're capoing.
Alternative that's more pricey: use the elixir nano extra-light set in
PhosBronze ...it's the same gauge set as the 12-string lights. Then order rest of the individual strings: in PB for the wounds, and plain steel for the rest. "StringsAndBeyond" will allow you to do so, and though the total cost is more than a regular 12er set, I
much prefer the PBs for my 12 than the 80/20s. And FWIW, I emailed elixir about PBs and they have NO plans on assembling a 12er set in PB ...which annoys me as it's not like they really have to "do" much of anything outside of packaging!
Hope that helps you a bit.
Edward