As we have become accustomed to of late ! It would appear that ARC Central have circulated an, as yet, confidential memorandum amongst their distribution network in respect to an SE upgrade program for the current Ref line. This leak emanating from a source 'close to' an ARC dealer.
Initial reports make mention of $1K for Ref75 and $2K for Ref150, which if close to accurate, surely cannot include any meaningful upgrade to the Iron, therefore we may well be looking at a handfull of PSU and bias circuit components in optimising the utilization of the KT150.
Jasper.