Neil, I did say I could be wrong! I found a more comprehensive datasheet
http://www.mif.pg.gda.pl/homepages/f.../093/6/6J5.pdf which suggests the 3.9K is a little low (4.7K or perhaps 5.6K depending on HT) not as much as I had thought - it will be running at <1mA anode current. As mentioned above the gain is 15 whilst the EBC33 acheives 23.