Thank you.Yes- you can definitely do this, I do this all the time. After purchasing my GA TRP3 I realized that I really didn’t care much for the newer tubes that were out there, so I turned to the used/NOS market.
I sometimes do bulk buys but I also buy pairs and singles. I keep them around until I can round up whatever is required to complete a quad. Surprisingly, I’m often able to find matching tubes that were produced within the same month/year but that’s just a bonus. I typically just try to find matches that are from the same production series, meaning facility and year range of production.