The Brimar CV4004 is an excellent UK made 12AX7 with a quasi boxed anode. Long plate construction, superb for phono stages, hifi, and guitar amps! We have a limited supply of low noise selected tubes, as well as Brimar CV4004 with balanced sections. $119.99 per tube!
Very sweet sounding tubes with smoother low end and crisper high end than the original driver tubes. This is strongly recommended in tube-rolling threads, among others. Well worth the cost to upgrade.