To the best of my knowledge, EI did not manufacture a short version of this tube. But short versions were manufactured by other companies, including Siemens. I tried the short Siemens and didn't like it. On the other hand, tall versions by GE, Mullard, EI and Sylvania have been favorably reviewed in the main Little Dot tube rolling forum. And yes, the proper LD setting for the 6HM5 is EF95.
10/18/16 at 8:37am