See this page:
Amplifiers: Amplifier parameters
There's a subheading titled "Zobel Network" that talks about this in some detail.
Amplifiers: Amplifier parameters
There's a subheading titled "Zobel Network" that talks about this in some detail.
Thanks for the linkie.
Its recommendation for a Zobel network on the output jack of a solid state amplifier is well made. However, the wording includes a lot of “all solid state amps” business, which in fact is not always true.
I have personally designed and implemented fairly high powered solid state amplifiers that are quite happy with capacitive loads, and do not result in positive feedback, at any frequencies. However, all these amplifiers did not have a 'final stage' negative feedback loop.
Feed-forward correction networks, yes.
Feedback, no, or limited.
So, I guess it is all a matter of perspective.
⋅-=≡ GoatGuy ✓ ≡=-⋅
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Also… one might also point out that “the Zobel network” can be placed into the feedback network itself, in an inverted topology. On doesn't really have to wrangle with the output itself, just the loop back to the negative feedback injection point.
Note in the article, that the last circuit has identified a number of 'stability' enhancing capacitors at various points. This, too, is part of the solution.
Lots of the Pass circuits also don't require one.
If you grew up working on solid state circuits from 1970-1990, you'd likely believe that every solid state amp had a zobel on the output.
If you grew up working on solid state circuits from 1970-1990, you'd likely believe that every solid state amp had a zobel on the output.
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I would guess tube amps sometimes use these networks to address ringing in the OPT
The first post shows an output inductor, not normally considered to be part of the R + C zobel per se
The first post shows an output inductor, not normally considered to be part of the R + C zobel per se