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In Reply to: Re: Clueless in Switzerland posted by Dan Banquer on March 12, 2007 at 09:00:33:
I AM TALKING ABOUT RESIDUAL NOISE YOU IDIOT!! I know very well what S/N ratio is it is part of basic training for analytical chemistry and used constantly in analytical spectroscopy for determining the LOD of a substance and that is not what I am talking about. It doesn't matter if the data is mass spec or audio data, same same. GOD, why do you insist on being obtuse to try to make points??As to S/N, the measurements I have seen for a 1Khz sine wave at 1 watt show the noise floor at -125db above 1Khz for the distortion spectrum. The power supply noise is all lower than -90db. At 10 watts the noise floor was -130db where the harmonics are present and the power supply still at -90db or better.
"In addition your Apogees are very inefficent so residual noise will not be as audible as S/N"
Did you hear me talking about the noise on my F(*?ing Apogees? I mentioned the review where they used Avantegarde Duo Horn speakers (103 db/watt) and heard nothing. I personally have put the big brother of that amp on my friend's Wilson X1 Grand Slaam speakers, which are 95 db/watt and heard NOTHING, no hiss, no hum, nada. Got it yet, Dano?
Follow Ups:
"As to S/N, the measurements I have seen for a 1Khz sine wave at 1 watt show the noise floor at -125db above 1Khz for the distortion spectrum.If that is not physically impossible it's damn close. Either you are lying, or you don't know how to make the measurement. Probably both.
Once again; Morricrab: No one else except you claims measurements like that, No One.
Duh!
"If that is not physically impossible it's damn close. Either you are lying, or you don't know how to make the measurement. Probably both.
"I am not lying nor did I make the measurement so actually, wrong again Dano. Like I said if you look at the power supply noise its up around -90db at 1 watt. Its a standard FFT of THD+N residual for 1Khz input at 1 watt power. Obviously 1Khz is notched out for greater clarity. Above 1KHz the noise floor shows -125 db because there is essentially no IM distortion with the power supply harmonics (seen this with a lot of amps both SS and tube), which looks like fuzz around the harmonic peaks. None of that funny business here. Just clean sharp peaks and residual noise.
Its in the magazine, I am just reading the graph. What? Your amp doesn't look as good? Check out that schematic there might be a bug! HA! LOL!
No; you got it wrong. If I remember my analyzer theory, when you do a distortion measurement you divide the bandwidth into very small sections. When bandwidth is decreased the noise gets lower, and as bandwidth increases the noise increases.
You need to do a real S/N with a full bandwidth of 20Hz to 20 kHz, and not interpret that from a distortion measurement. Remember what I said to you: No one has gotten those numbers except you; and you're not very special in that regard.
Stick to Chemistry;
d.b.
Well obviously it was wideband, Dan or else there would not have been the 50Hz (plus harmonics) from the power supply would there? The graph bandwidth is plotted from 20Hz-20Khz. Obviously, if you average all the values over the whole bandwidth you probably end up with something around -100db or so. However; all the information is there, its just not as straightforward to interpret as a single S/N value. You have to have a signal in order to have a S/N ratio, in this case they have a 1khz sine wave at 0db. All the noise and distortion are captured in the FFT from 20-20. The point is that no single component of the noise was above -90 db and no distortion component above -50db (and then only 2nd harmonic with the rest way down).For the record, I never claimed the amp had a signal to noise ratio of -125db. -100 db is probably closer to correct given how quiet it is into even very sensitive speakers. All that you have been blabbing about doesn't at all invalidate mine and other reviewers observations that there is no noise present at all even with extremely sensitive loudspeakers. I have heard plenty of so called low noise amps that cannot pass this obvious test.
Far be it from me to try and correct you. BTW: Do you have your Clever Little Clock yet?
ROTFLMAO;
d.b.
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