[Freq Band]

I am curious how to test for these measurements, being that they help determine compensation caps' values.
(and "overshoot" ?)

(I am a novice, and this is about advanced as my knowledge allows ....so forgive me if my terminology is not correct.)

Or, are these answered on the opamp's datasheet? If so, how does one determine a value when the opamp is paired with a buffer?

Is the compensation cap value determined by the opamp's needs only, regardless of a buffer put on it's output?

(Buffers I use the LH0033, LH0002, and BUF634...in building my amps.)
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You can look at my current amp here:
Example, the 18pf cap is there a better/best value?
http://www.head-fi.org/forums/showthread.php?t=223073
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I have a 4ch O'scope, and a Funct Generator, and a DMM.

=FB=

 

[Pars]

Amb or someone with a more R&D background might pipe up, but I think you could just run a square wave (clean) thru the amp and look at it on a scope. You'll see any over/undershoot there and see what effects compensation has on it. Also, running RMAA on the amp might prove valuable as well. And of course, listening to it

.

Chris

 

[heatmizer]

you may also be able to use Sia Smaart to analyze the the phase shift and delay through the amp

 

[error401]

Quote:

Originally Posted by Pars /img/forum/go_quote.gif Amb or someone with a more R&D background might pipe up, but I think you could just run a square wave (clean) thru the amp and look at it on a scope. You'll see any over/undershoot there and see what effects compensation has on it. Also, running RMAA on the amp might prove valuable as well. And of course, listening to it . Chris

A sine wave would probably be more useful to take a look at phase discrepancies, but I don't think there's really a good way to analyze this on a 'scope. I'd probably use a dual trace scope with a sine wave at a few different frequencies. Compare the input to the output, you should be able to see any phase difference easily. The problem is that the amp must have some phase lag, we care that it's linear across the frequency domain, not that it exists. Comparing the 'baseline' (say 1khz) lag to the frequency you're looking at might be difficult; I suspect that at most frequencies the lag through the amp will absolutely dwarf any nonlinearity, making it hard to measure.

RMAA is a good idea, though it doesn't give any (direct) information on this. It might be enough to tune the compensation network though. Not sure...