Just go for it. You KNOW you can do it!!!
Just go for it. You KNOW you can do it!!!
Is there a chicken emoji anywhere?Thank you
Good. But, as a general rule, you don't need to worry about noise outside the audio band- except that it's good to simulate it to check to see if there are any pathological issues that could be exposed by it. Sometimes resonances and other issues are apparent looking at the noise and are less so when looking at the frequency response- for instance a near oscillating current mirror or current source would not necessarily appear in the frequency response but would appear in the noise.
Which small resistor in which simulation? Sometimes you just have to look closely enough. If we're looking for responses within a few 10s of mdB sometimes you need to zoom in...."getting to know you...."
A brain dump would be much faster and more efficient,
but that is still a ways off.
Wyn, while you are here...
...Why when I changed the value of the small resistor in the
feedback path made no difference in the output from yesterdays post.
Then I'm off again to buy the wife's cars.
The stealerships do this to me.
because I don't
and accept their fees, add on, etc.
I looking for an
but I get these
my jaw
they're words
you said you would treat me
but you treat me
I say, Hasta La Vista....arsch loch.
So as our Native Home Boy sings LINK
The post wouldn't be complete with out my kids favorite
emoticon....
USMC_Spike
Post Script - When the dust settles, and I bring home
the wife's new vehicle and see her smile, I'll work the sin again.
Remember the ac sim does not care about the amplitude of the input- except that it simplifies the interpretation if you normalize the input to the desired input level so that you get the desired output level.woops, not yet. Where do I enter to make it a 5.5 VRMS normialized input?
The other sim, let me find it and put it below here. I've got about 30mins I think.
A black window appears. Left click on the output node that you defined and you get the output noise spectral density (V(onoise)).
Press Ctrl and left click on V(onoise) on this plot and you get the integrated RMS noise over the specified frequency interval (say 200uv) The ratio of the output signal (1vrms for the specified input, either with an input of 5.5mv at 1kHz etc. or 2.5mv for the "new" design" ) to this is the signal to noise ratio, usually expressed in dB- i.e. 20 log (1/(2*10^-4))= 74dB.
However, noise is usually not specified over an unweighted bandwidth as it's not a realistic reflection of the sensitivity of the ear.
The unweighted one is often called Z weighting (Zero weighting) and the most common one is the A weighting.
If you look at your noise plot you will see that it's labelled v(onoise). Remember, the frequency response and noise simulations are different animals.Here is where I am I only see V(outmixed1) I cannot find the V(onoise) either in schematic or the plot.
I went back to the original mixedriaanew schematic and plot.
View attachment 1381987
Are you talking about a transient analysis? There is a way to do a chirp in transient- is that what you're asking?Then If I want to do a sine sweep, do I just input a 1Vrms @1kHz ?
Follow the instructions in the earlier post. It's still the same noise simulation that doesn't care about the input level, but with the network added after the amp output.Then If I want to do a sine sweep, do I just input a 1Vrms @1kHz ?
Then how do I add the Aweighting to it. That might be the second paragraph
or the last paragraph but haven't worked my way down to that yet.
V(onoise) does NOT refer to a circuit node. It refers to the output noise (onoise) voltage. It's measured at the node you specified in the simulation command.Here is where I am I only see V(outmixed1) I cannot find the V(onoise) either in schematic or the plot.
I went back to the original mixedriaanew schematic and plot.
View attachment 1381987
Yes, however have you managed to insert the A weighting network?