I have been listening to Telefunken NOS 12AX7 since yesterday after 4 days of break-in. Let me first say JJ 12AX7 are excellent tubes for the money. My biggest concern was noise with Tele NOS. Fortunately, they turned out to be dead quiet.
Now the differences, JJ pair in contrast were slightly darker and bit forward in mid-range. Tele NOS definitely has more refined mids, slightly sweet and smoother top end. If I may say so, excellent layering and microdynamics too and very emotionally engaging.
They are allowing me to fully appreciate Ben Webster’s velvety and breathy tenor saxophone fully bodied sound at another level. I own several recordings of Ben’s music and every one of them giving me goosebumps :-)
I can’t praise enough my Model 4 phono…what an amazing bargain! I may order another one for my 2nd tonearm.
Thank again!