Having used both Tube Depot and The Tube Store in the past, I would highly recommend Brent Jessee at audiotubes.com.
He is well respected and can give you his personal recommendations.
REF5SE tubes
Time to retube. If tube’s direct from ARC and NOS tubes are not in the picture, what would be next best for tubes? Haven’t purchased anything from Upscale , so that’s out.
Appreciate any and all advice.