[Heathkit] How about the SB-220?

[Jim Shorney]

On Sat, 22 Aug 2009 12:32:27 -0700, Paul Baldock wrote:

>I'm not sure this is true. I have rebuilt two SB221's and grounded 
>the grids directly. This does give more gain and allows you to turn 
>the driver rig down. Turning the driver down from 100W to 90W on a 
>12V rig greatly improves its IMD and more than the negative feed back 
>that the amp "may" have with the Heathkit design.
>
>I have had no instability problems and the output is very clean. I'm 
>not aware of any modern 2 X 3-500Z amps that use the Heathkit method, 
>they all directly ground the grids.


After reading all the pros and cons of this idea, I came to the conclusion that
the reasons for directly grounding the grids made more sense (to me) than the
alternatives. I grounded the grids in my L-7 and it has been running great that
way. FWIW.

73

-Jim


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