I've beem using the Audiable Illusions Modulus 3A with a Music Reference RM9 MK II for about 15 years. I've settled on 6550 tubes but the KT88 is tempting. I like the Chinese 6550 as much or more than, the Winged SED 6550 when listening to overly vivid recordings... but then, excellent recordings sound a bit muffled. I hesitate to upgrade to the Modulus 3B and the RM200 Mk II because I'm afraid I wont like them as much. I've used NewForm,Maggies,Totem and now, modified NewForm's...Tiare, with great success. Hope this helps.
