Bias
Tables

To make life easier
when biasing, (i.e. "...where's that damn calculator!"), I've put together some
tables to tack up on the work bench.

Keep in mind these
dissipation figures were taken from old RCA and Sylvania tube manuals and should
be fine when using N.O.S. tubes. However, with the quality of some current
manufacture tubes, it may be a good idea to use even more conservative
dissipation ratings.

EL84/6V6GT -
12W

Hot
(70%)

Avg (60%)

Cool (50%)

200V

42mA

36mA

30mA

225V

37mA

32mA

27mA

250V

34mA

29mA

24mA

275V

31mA

26mA

22mA

300V

28mA

24mA

20mA

325V

26mA

22mA

18mA

350V

24mA

21mA

17mA

375V

22mA

19mA

16mA

400V

21mA

18mA

15mA

7189A
- 13.2W

Hot
(70%)

Avg (60%)

Cool (50%)

200V

46mA

39mA

33mA

225V

41mA

35mA

29mA

250V

37mA

32mA

26mA

275V

34mA

29mA

24mA

300V

31mA

26mA

22mA

325V

28mA

24mA

20mA

350V

26mA

23mA

19mA

375V

25mA

21mA

18mA

400V

23mA

20mA

17mA

EL34 - 25W

Hot
(70%)

Avg (60%)

Cool (50%)

300V

58mA

50mA

42mA

325V

54mA

46mA

38mA

350V

50mA

43mA

36mA

375V

47mA

40mA

33mA

400V

44mA

38mA

31mA

425V

41mA

35mA

29mA

450V

39mA

33mA

28mA

475V

37mA

32mA

26mA

500V

35mA

30mA

25mA

6L6GC - 30W

Hot
(70%)

Avg (60%)

Cool (50%)

300V

70mA

60mA

50mA

325V

65mA

55mA

46mA

350V

60mA

51mA

43mA

375V

56mA

48mA

40mA

400V

53mA

45mA

38mA

425V

49mA

42mA

35mA

450V

47mA

40mA

33mA

475V

44mA

38mA

32mA

500V

42mA

36mA

30mA

6550 - 35W

Hot
(70%)

Avg (60%)

Cool (50%)

400V

61mA

53mA

44mA

425V

58mA

49mA

41mA

450V

54mA

47mA

39mA

475V

52mA

44mA

37mA

500V

49mA

42mA

35mA

525V

47mA

40mA

33mA

550V

45mA

38mA

32mA

575V

43mA

37mA

30mA

600V

41mA

35mA

29mA