MultiSim allows for FFT parameters (no. of points, no. of harmonics to consider). I'm sure other sims use their own default sets of parameters. It would be interesting to see whether results stack up when you actually equal calculation parameters across them all.
Vary different. Just use identical circuit across the board with identical models.
You can download the demo versions of the software free from their respective sites.
Did you actually set the number of FFT points and number of harmonics AND the methodology to either IEEE or ANSI/IEC all the same across the sims...
Or (which is my guess) did you just load up the identical circuit using each sim's defaults/
Just use LTspice; it's free and is probably the best.
Where possible, I recommend the decent models that I have tweaked that are available on my website at CordellAudio.com - Home.
Seriously Mike, have you made the comparisons apples to apples among the simulators you mention above?
Cheers,
Bob
Looks like I have to try LTspice more seriously then. I find the controls hard to get into after using MS for so long. Could I perhaps persuade you to develop refined models of the ECX10N20/P20 by chance? I suspect the models I have aren't very accurate. I think I found them on this site a couple years ago.
Mike,
I think you need to share more specific details with us before we will attach adequate credibility to you assertions. What amp circuits did you simulate, what models did you use, what results were different and so on. Your one line answers don't inspire confidence in what you are saying. Quite frankly, I have no idea how much experience you have in designing, simulating and testing amplifiers.
If you have not bought my book, have you at least bought a recent edition of Self?
Cheers,
Bob
Not my problem; you are the one making the assertion.
As usual, when asked, you don't come through with the goods. I frankly doubt that you've done much of any of this. Zero credibility.
Bob
Michael,
You might think you outsmart most or all of us here.
You might even be right indeed.
But of course we are not taking it just because you think or imply so.
This is what peer review is all about, and works like a charm, in fact you may enjoy doing audio or whatever because giant forebears stuck to this.
Rodolfo
Rodolfo,
The reason I didn't waste my time with Bob is his questions, such as which topology was used, models used and which books I have read, are a laughable red herring from an Emperor with no clothes.
Even a first year undergraduate student would know that the topology used and models used are wholly irrelevant provided they remain the same across platforms for an apples and apples comparison.
What is so difficult about downloading Simetrix or Multisim and comparing (using any topology with any models) the THD results with those delivered in LTSpice?
The reason I didn't waste my time with Bob is his questions, such as which topology was used, models used and which books I have read, are a laughable red herring from an Emperor with no clothes.
Even a first year undergraduate student would know that the topology used and models used are wholly irrelevant provided they remain the same across platforms for an apples and apples comparison.
What is so difficult about downloading Simetrix or Multisim and comparing (using any topology with any models) the THD results with those delivered in LTSpice?
Michael,
I see. Speaking for myself, I should rather expect you doing this work and showing results, since you are the advocate on which the burden of proof rests.
I am not particularily interested or motivated but should inspect results with curiosity.
Others may have their own reasons for not doing it, perhaps because they have already done some work and are satisfied with results that conclude otherwise with respect to your assertion.
To do the work and share results is an excellent way of making things much clearer for oneself. Reportedly Einstein said you really understand something when you are able to explain it to your grandma.
So I guess there will be rational and fair judgement here for whatever results you may share, and if you prove right then the better for all.
Of course your credibility can only benefit from this.
Conversely, stubborn denial will only confirm supicions.
Rodolfo
A wonderful phrase with real meaning.
I have seen it happen many times when I am trying to explain something. It really makes one clear one's mind when trying to explain to a new listener/pupil/learner.
I cannot begin to list the number of things that I understand better after having written my book. That phrase is dead-on.
Cheers,
Bob