Atmasphere
Many thanks for being so forth coming with both, the how and the why of your investigations/insights on the Sonatas. Were it only so that more high end audio makers were so involved, and responsive to the fold.
Perhaps, my now quite extended use, with both SS and tubes driving them alternatively during different applications, (HT & 2 CH) has accounted for their now greater ease and control in conjunction with the EL34 monos.
What ever the reasoning, and your remarks do seem to add up regarding their initial stiffness, the current loosened up results I've heard from them now that theyre on the higher output taps, are more than enjoyable and a definite increase in obvious performance.
This switch was tantamount to integrating another component altogether!