
I have already tried rolling a couple of power tubes , the soviet 6n6pi and what seems to be pin compatable the Marconi B729/ECC802 ( which on the packet is labelled as a B729, ECC804 & 6/30L2) seemed to work ok but was a litle bass light but very detailed, I have tried them with a Brimar 8D3/6AM6 ( very weighty bass and nice mids with the 6n6pi's ) and the GE 5654w's seem very detailed with plenty of bass ...( both with grado sr80i)
I am trying to get a couple of GE 5 STAR 5687 an ebay then I'll have a go at making some adapters with some of those adapters sonda2008 spied :-)





























