ARC Ref 3: Tung-Sol 6550 in power supply?

OK guys, I have already installed NOS Tung Sol in the PS of my Ref 3. Now I'm wondering, how much time I should allow for burn-in (this is a brand new tube) ?

Elberoth2, I would give the Tungsol a couple hundred hours of playing time at various gain levels to stabilize. G.

I would recommend the (blue label) GEC KT88 for this pre. I experimented with Gold Lions and Gold Monarchs as well. These are 3 variations of the vintage Genalex KT88, not re-issues. While the I preferred the GEC best, it leaned towards the euphonic side. Despite its imperfections, it made going back an impossibility. I decided to either use this pre with the GEC or not at all. I still have the GEC if anyone wants to try it.

That's very interesting Ethannnn. Would you care characterizing in some detail the sonic results of the various tubes you tried on Ref 3? Thanks, G.

My recollection were all Genalexes had truer midranges. The Gold Lion was most detailed and dynamic, the Gold Monarch was most neutral, and the GEC was most full bodied. The GEC had the most impact while the other two were more subtle. In my system, the midrange magic of the GEC outweighed its shortcomings.