[Heathkit] SB-200 and 572B to GI7b conversion or new 572B's ??

[John Peters]

Hi All,

Just got a SB-200, in working order but tubes are lazy, only 300W out with
100W drive. So I need new tubes, there are a few options, buy a pair of new
572B's

Which ones are preferable ??  Taylor or Svetlana ??

Or should I convert the PA to a pair of GI7b's it seems others has done this
before.. I have a bunch of these tubes laying arround, they are much cheaper
than the 572B's and more solid too, but need more air so the PA will get
noisier. More gain, and a pair will last for ever in this configuration. 

Is this done before ??? And how should I make bias ?? Real GG design or like
with the 572B's with 200pf to Gnd and make a DC ground via some resistors (33
Ohms with the 572B's) to get the right Bias current.. 

any info is very much appreciated,

73! de John PA5MS