Just curious if anyone has tried different tubes in the GK-1? Seems like I read a post a while back from someone who tried different tubes and couldn't really tell much difference. I was at a huge surplus store over the weekend and found some NOS 6es8's for two dollars each. "Made in Germany" old RCA, GE, Sylvania, and Mullard. Seemed like too much potential fun to pass up. I'm trying the RCA's now and they sound pretty nice: better imaging, depth and bass (!) than the stock tubes. High freq's are a bit more subdued though.
This is my first experience with tube rolling, tho. Roughly how long does it take to "burn-in" tubes? Or does it vary on the brand, age, use, etc.?
