Mr. Curl:
Taking your answer at face value, you are implying good sounding like good tasting is firmly rooted in the nature of the beholder.
It is a well known fact that what tastes good for certain cultural group is unpalatable for other. That within our own region, city, neighborhood or family, there are people with different and more often than not antagonic preferences. This holds even within conoisseurs, not simply lay people.
That being the case for listening, then there is no hope for agreement regarding what should be widely acceptable.
We are then left with second best, to make the reproduction system as transparent as technology allows, so as to preseve what the artist meant when composing or performing.
To me this is quite close to objective evaluation.
Rodolfo
Taking your answer at face value, you are implying good sounding like good tasting is firmly rooted in the nature of the beholder.
It is a well known fact that what tastes good for certain cultural group is unpalatable for other. That within our own region, city, neighborhood or family, there are people with different and more often than not antagonic preferences. This holds even within conoisseurs, not simply lay people.
That being the case for listening, then there is no hope for agreement regarding what should be widely acceptable.
We are then left with second best, to make the reproduction system as transparent as technology allows, so as to preseve what the artist meant when composing or performing.
To me this is quite close to objective evaluation.
Rodolfo
Christer said:
SO what's your preference BJT/VMOS/LMOS.....
Tell us Christer...
BTW, Charles new amp uses Thermal Trak Bipolars from On Semi...I think he is back to BJT's
😉
Workhorse said:
Yes, this is one reason why Charles would be very welcome to participate on this thread, as he could share his insights, having been there, done that with both technologies.
Bob
I tried to contact Charles today by phone. He is not receiving phone calls, and is not reporting to his office.
However, the links provided by Workhorse are very interesting, especially his interview. If those of you who are interested in Charles Hansen's design opinions would just read his interview, you would gain enough understanding of his position, that you might find constant jabs at him are unnecessary and immature.
I would not expect him to come to this website in the near future.
However, the links provided by Workhorse are very interesting, especially his interview. If those of you who are interested in Charles Hansen's design opinions would just read his interview, you would gain enough understanding of his position, that you might find constant jabs at him are unnecessary and immature.
I would not expect him to come to this website in the near future.
john curl said:
It is a shame that you think that all of us (except Bob Cordell) are a bunch of amateurs and idiots, who have limited their horizon only to THD measurements. Of course, we also look at IMD (at least I do), but why 'triple tone'? Two tones are just enough.
There is really no need to measure more things like PIM etc., because of their inter-relationship with THD and IMD.
As for Bob's 'full output' measurements, probably you have overlooked fig.11 "THD as function of level" in the article about his famous EC-amp.
As for your 'golden ears', wouldn't it be wise to listen more carefully to what other people have to say, in stead of ignoring them or to put them off with a red herring?
john curl said:
Hi John,
Thanks for trying that. Is he still in bad shape from his accident? I would have hoped and prayed that he would have been in better shape by now.
I'll definitely check out those links.
Thanks,
Bob
Estuart, NOW you put you foot in it! ;-)
Why don't you look up triple beat distortion, caused by IM of 3 tones or more?
You might find that it is twice as sensitive as 2 tone IM. That's why we take classes at the university.
Why don't you look up triple beat distortion, caused by IM of 3 tones or more?
You might find that it is twice as sensitive as 2 tone IM. That's why we take classes at the university.
Bob Cordell said:
Hi Bob,
Here is a link to Charlie's blog which provides many details of what happened. http://blogs.ayre.com/charlie/. Looks like the last update was January, so I'm not sure what the latest status is.
john curl said:
Wow, twice as sensitive as 2 tone IM, unbelievable! 🙄
BTW, my distortion analyzer is only 100 times as sensitive as an AP (THD and IMD). That's why I took classes at MY university.
john curl said:
Well Said, John........
Charles Hansen, is well respected among audiophiles and hope he might be well soon and contribute in this thread....
Hansen interview - design philosophy
Gentlemen,
I try not to look as a dogmatic objetivist, and may be my contributions do avail this, yet I still cannot pass by statements regarding the existence of unmeasurable qualities tied to amplifier design that result in audible diferences.
No to be stuck in arguably debatable rationales for feedback vs. no feedback, discrete vs. integrated etc., the bottom line for me is a black box approach whereby what comes out is what matters.
Along this line, nothing could be simpler and more convincing than a null test, listen to the residue at the normal operating power level, and decide whether it matters or not. Note than in this case there is not even the masking produced by the desired signal to dilute whatever was left over as local "contribution".
Has anybody done this? Any results to share?
If this has been done comparing different design schemas, what can be argued in favor of the one with lower objective specifications (higher residuals) as to reproduction quality?
Rodolfo
Gentlemen,
I try not to look as a dogmatic objetivist, and may be my contributions do avail this, yet I still cannot pass by statements regarding the existence of unmeasurable qualities tied to amplifier design that result in audible diferences.
No to be stuck in arguably debatable rationales for feedback vs. no feedback, discrete vs. integrated etc., the bottom line for me is a black box approach whereby what comes out is what matters.
Along this line, nothing could be simpler and more convincing than a null test, listen to the residue at the normal operating power level, and decide whether it matters or not. Note than in this case there is not even the masking produced by the desired signal to dilute whatever was left over as local "contribution".
Has anybody done this? Any results to share?
If this has been done comparing different design schemas, what can be argued in favor of the one with lower objective specifications (higher residuals) as to reproduction quality?
Rodolfo
dimitri said:
-152dB and -136dB
Never mind.
Hi Dimitri,
No, about 10dB more. I didn't specify which model you know 🙂
Cheers,
john curl said:
Hi John,
Actually, I don't need that 6dB, but it may be useful to speed up the averaging process (to get rid of noise) by a factor of 4.
BTW, is triple tone IMD your favorite?
Cheers,
estuart said:
Wow, twice as sensitive as 2 tone IM, unbelievable! 🙄
BTW, my distortion analyzer is only 100 times as sensitive as an AP (THD and IMD). That's why I took classes at MY university.
Hi Edmund,
Tell us more about your analyzer and the setup you must use in order to beat the AP by such a large factor. This is a strong area of interest for me. Tell us at what frequencies you are talking about and what actual residual you get, in what analyzer bandwidth. For example my analyzer from 25 years ago has a residual THD+N of 0.0006% at 20 kHz in a 200 kHz analyzer bandwidth. Also tell us if the numbers you achieve need to include the use of spectral analysis and/or a Distortion Magnifier technique like the one I described in my MOSFET power amplifier paper. It sounds like you've done some really good work here.
Thanks,
Bob