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Question to Carl

4/14/2000 10:26 PM
Bjorn	Question to Carl Carl, In an earlier post on Ampage ju said: Here's what I like to do to my Fenders.... 1) change the input grid stoppers to 33k 2) change the cathode bypass caps to 5uF. 3) change the power tube grid resistors to 100k and the grid stoppers to 4.7k 4) change the driver coupling caps to 0.047uF 5) change the driver input cap to 0.01uF 6) change the feedback loop values to 22k/4.7k 7) add a 120pF cap across the plates of the driver to supress oscillation. (good insurance if you don't have a scope) Since the atmosphere here on Ampage is very friendly (I believe it is) – even to us guys who really don’t understand s—t about electronics I don’t hesitate to put this really basic question to you. Ad 2. change the power tube grid resistors to 100k and the grid stoppers to 4.7k What are the grid stoppers? What do they do? Why would I like to change their value to 4.7k? Where do I find these resistors (by the PI?) and what values do they originally have? I would also like to take the opportunity to thank you (and Bruce) for some very good posts. Bjorn

4/14/2000 10:26 PM

Bjorn

Question to Carl

Carl,
In an earlier post on Ampage ju said:
Here's what I like to do to my Fenders....
1) change the input grid stoppers to 33k
2) change the cathode bypass caps to 5uF.
3) change the power tube grid resistors to 100k and the grid stoppers to 4.7k
4) change the driver coupling caps to 0.047uF
5) change the driver input cap to 0.01uF
6) change the feedback loop values to 22k/4.7k
7) add a 120pF cap across the plates of the driver to supress oscillation. (good insurance if you don't have a scope)

Since the atmosphere here on Ampage is very friendly (I believe it is) – even to us guys who really don’t understand s—t about electronics I don’t hesitate to put this really basic question to you.
Ad 2. change the power tube grid resistors to 100k and the grid stoppers to 4.7k
What are the grid stoppers? What do they do? Why would I like to change their value to 4.7k? Where do I find these resistors (by the PI?) and what values do they originally have?
I would also like to take the opportunity to thank you (and Bruce) for some very good posts.

Bjorn

Replies:

jason Not Carl here but I can help a tad ... -- 4/15/2000 12:13 AM
Carl Z Bjorn;As Jason poin... -- 4/15/2000 8:05 AM
Bruce q{In an earlier post on Ampage ju s... -- 4/15/2000 4:27 PM