Hows that tube cooler working for you? 
It LOOKS cooler.

I had purchased a set of JJ ECC803s Gold Pins after my Psvane 12AU-7T episode. I could not here a difference in sound quality. Ian sent me a set of 12AX-7Ts as a replacement for the 12AU's so I tried it for a bit. Much better than the 12AU's but again I could not here a difference between it and the original 803 that came with the buffer you installed.
But the mystery piece is:
The EAT ECC803S, and it thrilled me immediately. Before, I could always tell when the buffer was on ... there was a tad of floor noise that wasn't present when it was out. The EAT valve is dead silent in my 901 and my system sounds awesome to me.
Did I mention it looks cooler too?
Dave