Philips 6681SQ (12AX7) Premium NOS Tubes, Pair, Sl. Used

For sale are 2 slightly used NOS Philips 6681SQ 12AX7 tubes as seen in the attached pictures.
These are arguably the best-sounding 12AX7 variants ever made. The 6681 is an instrument-grade 12AX7 and the SQ stands for Special Quality. They are quite rate and of early 70s vintage with O-getters.

Price is $150 for a matched pair.

I have rated them as 8s on the rating scale due to their obvious age but they still have nice shiny getter flashing and sounded terrific in my CAT preamp, which I no longer have, so these are extra tubes. I estimate I put between a few hours and a few hundred hours on them, which is nothing more than break-in on these tubes designed to last 10,000 hours. Unfortunately I do not have a tube tester so I am pricing accordingly, but they are guaranteed to work perfectly or I will refund your money.

Please note that these tubes are for sale on Ebay and online sellers for over $150 per tube, so here is a chance to hear the ultimate performance of your equipment at a bargain. I have extensive positive feedback on Audiogon and Ebay as rlawry, so buy with confidence.

In my CAT preamp I found them to have a direct, punchy, warm sound with great dimensionality. These things are way, way better than current production tubes and still significantly better than most other 12AX7 variants, many of which I tried. They will never be made again, unfortunately.

I can ship worldwide and will cover Paypal fees