These are my back-up quad. They are matched. These compared favorable to the EAT KT-88 Diamond in this review,
http://highfidelity.pl/@main-224&lang=en. They are in high demand for owners of Audio Research gear. They were new from USA Tube. $99 each or $375 for a quad. Retail is $185 per tube. Please add 3% for PayPal and shipping.
