I've been running the EML 2a3 for 6 months now and have a hankering for something else (not EH Stockers either. Anyone try the KR 300BXLS or can make a recommedation towards something else?
The 300BXLS takes more filament current than the power supply rating. It may work - I have not tried - but I can't recommend it. Most likely is a reduction in lifetime of the power transformer or diodes, I can't say how much.