I don't have any revisions (yet... :-) on my DNA-125, but if you hear much graininess (not sure what 'grunty' means as a complaint), I would ask if you're leaving yours permanently powered-on. Not turning mine off seems to eliminate just about all significant hints of grain by day 2.
BTW, on a tangent, I've recently played around with auditioning my 125 hooked up to only one speaker, to make the comparison with my tube monoblocks more fair in terms of power supply demand vs. capacity. The results hint tantilizingly at what may be expected from an SMC power supply upgrade (only Platinum upgrades the power transformer), not to mention monoblock conversion.
BTW, on a tangent, I've recently played around with auditioning my 125 hooked up to only one speaker, to make the comparison with my tube monoblocks more fair in terms of power supply demand vs. capacity. The results hint tantilizingly at what may be expected from an SMC power supply upgrade (only Platinum upgrades the power transformer), not to mention monoblock conversion.