Thanks Jude, I kind of suspected frequency vars between C and D having something to do with it. Both accordions go thru extensive individual pre-gig eq'ing but yours needs minimal adjustement compared to Larry's C.
Thanks all for you input.
JP

the difference between larry;s and jude;s
may also be mic placement.

where is the mic, in each one?
where does it point, how close to the reeds?

wle.