If you monitor white noise with a sampling scope, will the representation on the screen be an accurate representation of the noise at HF?
I’m tending to think no, but maybe one of the experts could chip in?
I’m tending to think no, but maybe one of the experts could chip in?
I hope you can see how the CW and 10X sampling is perceived as a red herring, and bringing different oscilloscope sampling techniques into the discussion makes no sense. All that's needed is fast enough sampling for the required BW, whatever that may be.
Just to clarify, you're talking about an equivalent time sampling scope? Not a real time single shot? I think there's been some confusion (might be just me) in some previous posts.
Went over that already.... WE think 40Khz or more is better. That should be the absolute minimum.
24/96 and higher. 24/192+ makes me happy.
THx-RNMarsh
Last edited:
Last edited:
Not really a red herring. There are other ways. BUT, you are right about....
All that's needed is fast enough sampling for the required BW, whatever that may be'
At least 40-50KHz is needed. But "for the required BW"..... there is NO required BW as there is in a communications systems (channels, groups, super groups etc). And, we dont have to fit data onto a rotating mechanical disk any more (LP or CD). We can be wide open if we wish. 20KHz was a minimum which has audible consequences with too low sampling rate, sharp cut-off filter system.
24/96 to 24/192 and above works better. hahaha. had to say that zillion plus one more time. ;-)
Are we all done?
Enjoy your music.
THx-RNMarsh
Last edited:
And you apparently pulled 40kHz out of the air for, as far as I can see, the reasons that "we've known that for a long time and limits of mics and speakers etc" I wonder, in reality, what BW is required for "accurate" rendition?
Looks quite similar to the measured (?) performance graph in the AD713 datasheet.
So doubling the capacitors would result in a cut off frequency below 20 kHz (~17 kHz) which might be too low if used as an anti-aliasing or anti-imaging filter in a 44.1 kHz system.
Yes, so one of the scopes that does say 10x oversampling. I have a Tek MDO3024 200 MHz that does 2.5 GS/s (so 12x if I understand it correctly). Seems it should be ok but. Maybe a better example is an audio DAC fed with white noise. I guess the answer is up until Fs/2 it’s ok but after that, aliasing aside, it falls off the rails.
John,
The reason for the repetitive design was because the horizontal stuff: clocking, and triggering, were faster than the vertical ADC. A sample/hold could be used to give the ADC time to digitize a very short-time sample. The technology at the time made that type of scope possible.
Today, ADCs are much faster and can operate more in real-time up to higher frequencies. That makes it possible to digitize non-repetitive waveforms at higher frequencies than before, as many DSOs now do.
After digging into it, seems as though the download feature in the tidal app is dependent on your subscription.....no verification no playback (apparently it verifies every so often), and the files cannot be copied without another (supposedly illegal app, as in if used for illegal activities ) to do so.
So being as it’s so tied to your subscription they still consider it streaming and is legal.
‘Good enough’ is the term I keep hearing, I’m with Richard.....why settle for that?
Last edited:
Mark, those things are bigger than my refrigerator and their not even the the biggest ones!
Matt, it’s all about performance, high performance! 😛
Matt, it’s all about performance, high performance! 😛
The sampling scopes I've used in the past rely on the input waveform to trigger the sampling system. For example, you can lock the trigger to a positive going zero crossing. The sampling system will start at a specific time after that trigger instant, and trigger the sample circuit every cycle of the repeating waveform.
If you are sampling a 500 MHz repeating signal at 100 pSec intervals, it will trigger the sampling head every 2 nSec and add 100 pSec delay every sample grab. So, the scope only needs to convert every 2 nSec, but effectively it is capable of discerning at the 100 pSec level.
If the waveform is changing all the time, this system will only be able to single shot at the converter rate, which could be 1nSec in my example.
In essence, my hypothetical scope example can see a repeating waveform with 100pSec resolution, but for a non repeating waveform, only 1 nSec intervals.
Jn
Last edited:
Yes, but I'm interested in what that actually means, rather, for example, stuff like this Sound Quality Comparison of Hi-Res Audio vs. CD vs. MP3 | Sony UK
Richard, Did you look at the Legacy Wavelet? They also have a pro processor.
Wavelet DAC/Preamp/Crossover | Legacy Audio - Building the World's Finest Audio Systems
Matt, that Sony site you posted definitely looks like a cash grab!
Last edited:
Ahh ok got it. I guessed it was something along these lines but I was not aware of the detail. This in effect then band limits the signal in the case of a non repeating waveform, but in repeating waveforms, you can actually see ‘into’ much wider bandwidths- one example would be fast rise-time signals.
(There are still functions on my scope I haven’t got around to trying)