I went down to 680nF with the DC blocking capacitor because anything over 1µF was way too bass heavy in my opinion. Then I got the warm mids that were there into focus. As for the tube, I'll be honest - I've tried lot of tubes, built "triode switch" adapters between the tube and socket to test both triodes on the tubes, and burned them in for days. There are only two "available" NOS tubes that I think have that "expensive" sounding, direct character. They are the 5-star Mica GE6072 and the Siemens Halske ECC801S. There are a lot of noisy/crackly NOS GE6072s on the market though and they are all expensive. It can be an expensive and educational journey until you find the right one. All other tubes sounded dull, not detailed/washed out, lacked warmth, no character or were too loud. And the TF AC701 is more a expensive Lottery nowadays.The GE6072 has that sexy edge, is perfectly balanced, hard to explain. It's magical. The Siemens Halske mentioned is also excellent and more available, less noise, very proud sound. TF ECC801S were good but a bit too much noise.
