About two octaves higher than anyone can hear, which means about three octaves higher than someone our age can hear.
That is not what we are interested in. What does any RF interference do to the subtle musical details? Especially in the precense of the big stuff… i have yet to see real measurements that tell us about that.
RF can have subtle or catastophic effects (causing destructive oscillation for instance), that won't show up in your 96k max measures.
dave
RF can have subtle or catastophic effects (causing destructive oscillation for instance), that won't show up in your 96k max measures.
dave
AES E-Library Spectral Contamination Measurement
Hasn't caught on yet, despite being over 25 years back.
I think we can safely say that oscillation isn't occurring otherwise the product would be faulty. Either way high frequency hash polluting the stuff we can hear would still show up in a 96k measurement as it would modulate it. Signal contamination, especially in mixed signal environments, is a big thing. As are designs following correct design procedures. If the sensitive analogue sections are measuring as you'd expect them to then I wouldn't be worried.
But if you want to really talk about high frequency hash let's talk about some of the recording mediums used in high end audio...
You guys talking about this stuff? http://www.ti.com/lit/an/slaa565a/slaa565a.pdf
and this: Analog Devices: Analog Dialogue: Selecting Mixed-Signal Components for Digital Communications Systems—Part V
?
and this: Analog Devices: Analog Dialogue: Selecting Mixed-Signal Components for Digital Communications Systems—Part V
?
An externally hosted image should be here but it was not working when we last tested it.
Sh!t just got extremely serious.
Got this monstrous Weiss DAC1 mk3 on my tweeters RAAL 210-10D and i almost fainted.
Out-of-this-world holographic feeling. Pure pornaudio. Almost unatural resolution and yet very liquid and analog-like...
It's scary. I mean, litterally: i jump on my seat when some tunes starts...
Wow. I'm not easily impressed but that thing is MASSIVE. 😱
All that RF noise must be affecting the performance of the Tektronix RSA3308A DC to 8 GHz spectrum analyzer I use at work, since it's a PC inside and all, powered by Chinese SMPS and runs Windows. Same thing with the GHz scopes, mini-ITX Intel PC motherboard inside. Hmm what about those new Agilent VNAs...
Clearly it is impossible to make a good DAC in such a "hostile RF environment" (whatever that means). I mean, we know how much harder it is to make an audio frequency preamp or DAC compared to a spectrum analyzer or GHz++ VNA.
No way could a manufacturer like Lynx do their homework and make their design robust enough to be immune to these things... I mean really who actually engineers audio products? Not most of the crap seen here anyway.
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I am sure that at $16k on sale it is not your usual PC.
http://www.bellnw.com/manufacturer/Tektronix/RSA3308A.htm
dave
Dave - you might also find these AP FFTs interesting showing around 30dB increase in the noise floor when a USB DAC isn't isolated from the PC - exaSound Audio Design > e12 > e12 Measurements (scroll down to the bottom).
Actually, I have taken it apart before it went for calibration last year. It is a usual PC. It has an ATX backplate and everything sticking out the side.
The Weiss stuff typically has excellent measurements. I think the new ones have discrete op-amps designed by Samuel G in the output stage.
Probably not the world's best because it doesn't use an R2R chip from the 90s though. 😉
I have an EMU 1820m that is not isolated from the PC ground and doesn't have measurements that look like that. Seems as if other people are able to get good measurements without galvanic isolation. Not that it's a bad thing, but there are other products out there that do not have isolation that don't have noise floors that look like that.
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But i bet all the special stuff is specially canned.
The usual PCs i see are not great. I can't see Tek starting with anything but a really good PC.
dave
Yeah, I am sure they have designed the analyzer to tolerate the environment, but that's the point. Why can't a sound card manufacturer do it? RF filtering doesn't need to be expensive. Capacitors, ferrites, common mode chokes, etc, are not prohibitively expensive.
It looked to me very much like generic motherboard OEM'd by like Foxconn or one of those OEMs. Much less impressive than the stuff you can buy at Newegg from ASUS or the like. It didn't have very high quality looking caps or inductors.
It looked to me very much like generic motherboard OEM'd by like Foxconn or one of those OEMs. Much less impressive than the stuff you can buy at Newegg from ASUS or the like. It didn't have very high quality looking caps or inductors.
They could, but most are likely under price pressure.
Ones that do take extra care will have way fewer issues.
I wouldn't fret too much about the board -- Foxcon makes excellent boards for Apple -- it is all the stuff around it.
dave
Ones that do take extra care will have way fewer issues.
I wouldn't fret too much about the board -- Foxcon makes excellent boards for Apple -- it is all the stuff around it.
dave