formula 977
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Who said that?Why on earth would you advocate for lower output voltages?
Who said that?Why on earth would you advocate for lower output voltages?
It doesn't get simpler but if you are not paying attention, then you won't understand the answer already given, or this one.I asked this question previously, you probably missed it. Which of the Cambridge measurements is valid, the ones in the first review or the ones in the second review. It doesn't get any simpler than that.
He did. Are you not reading anything before commenting? He said to test the unit before clipping which means lower voltage.Who said that?
I think we can all chill a bit about apologies and such, I agree with that he retested, gave the opportunity to show that it's a competent unit, and gave the precision on what has changed and why. Amir have put the extra work, no apologies needed there. But still we could debate about if "It's on Cambridge":
"Issue was brought up that this is an instrumentation thing that the Audio Precision analyzer is creating a loop and ground noise that would not be there. While this is true, I explained that I have tested hundreds of DACs that don't have this problem."
So the key word here is: instrumentation issue. If a measurment shows a problem that don't exist in real life usage, we can hammer as much as we want that others don't have this "problem", but if it's only present when you connect an AP and in no other situation, if the matter is understood, and it can be demonstrated that no possibility it creeps into the audio signal when listening to music, well, it's a non issue, it's not "On Cambridge". Electronic designers need to use instrumentation of course, but they don't design to fix analysers weird behaviours. If some do, it may be by chance, it may be just different way of working the grounding scheme, or maybe they put the extra work on looking good on AP, but looking good on an AP analyser is not a design goal in itself, it's a consequence. If there is no problem, there is no problem.
Stunning level of reading incomprehension.....That statement is the 2nd review pretty much says the test equipment caused the ground loop.
Maybe I didn't understand something, but this seems like a huge negative. I think most people using computer audio are going to want to use the usb connection. If other companies don't have this problem, why does Cambridge?If you can't leave the USB cable connected without degrading performance that's a big negative. Can't imagine why anyone would accept that design limitation. Especially at a $1400 price point.
Stunning level of reading incomprehension.....
I tested using AP's Toslink output which fully isolates the AP from the device. The addition of USB from the computer, lowered performance.Did AP cause a ground loop or not, simple question.
I think you miss-understood the issue.I think we can all chill a bit about apologies and such, I agree with that he retested, gave the opportunity to show that it's a competent unit, and gave the precision on what has changed and why. Amir have put the extra work, no apologies needed there. But still we could debate about if "It's on Cambridge":
So the key word here is: instrumentation issue. If a measurment shows a problem that don't exist in real life usage, we can hammer as much as we want that others don't have this "problem", but if it's only present when you connect an AP and in no other situation, if the matter is understood, and it can be demonstrated that no possibility it creeps into the audio signal when listening to music, well, it's a non issue, it's not "On Cambridge". Electronic designers need to use instrumentation of course, but they don't design to fix analysers weird behaviours. If some do, it may be by chance, it may be just different way of working the grounding scheme, or maybe they put the extra work on looking good on AP, but looking good on an AP analyser is not a design goal in itself, it's a consequence. If there is no problem, there is no problem.
The noise was generated when a cable is plugged into the USB socket, even if the other end of the cable is not connected anywhere. That is not instrumentation problem that only exists within @amirm's test environment. It is a situation that can exist at any owners' set-up.amirm said:Issue was brought up that this is an instrumentation thing that the Audio Precision analyzer is creating a loop and ground noise that would not be there. While this is true, I explained that I have tested hundreds of DACs that don't have this problem.
I tested using AP's Toslink output which fully isolates the AP from the device. The addition of USB from the computer, lowered performance.
What you quoted was their theory before I investigated and found this issue.
??? I thought the USB was connected to the computer, completing the loop since the AP is also connected to the computer. ???I think you miss-understood the issue.
The noise was generated when a cable is plugged into the USB socket, even if the other end of the cable is not connected anywhere. That is not instrumentation problem that only exists within @amirm's test environment. It is a situation that can exist at any owners' set-up.
Please read the review again.??? I thought the USB was connected to the computer, completing the loop since the AP is also connected to the computer. ???
amirm said:We see noise intrusion reducing SINAD by a few dBs relative to TOSLINK optical. Here is a key discovery though: this is NOT due to USB input but mere connection of USB cable. You can see that noise even with Toslink when I have USB plugged in (but not used as an input):
[...]
Turns out this noise issue will proceed to corrupt the measurements of all other subsystems and was the reason why the amplifier for example did not perform well either in the first round. The impact with this second unit is lower than first sample though. This could be due to noise conditions changing on my test system (nature of computers and grounding) or something is different in the second sample.
To eliminate USB noise as a factor I continued the rest of DAC tests using Toslink so let's go through them quickly:
Me too.
As I understand it, in his setup having the USB connection (regardless of whether USB is being used) completes the loop between the computer, the CXA81, and the AP. Most of us probably won’t have a loop like that.Please read the review again.
Notice that @amirm tested the unit using Toslink input as USB input was still noisier. Emphasis is not mine.
You are simply assuming.As I understand it, in his setup having the USB connection (regardless of whether USB is being used) completes the loop between the computer, the CXA81, and the AP. Most of us probably won’t have a loop like that.
I don’t understand what you mean. My first sentence or my second sentence?You are simply assuming.
You said "Most of us probably won’t have a loop like that," which is an assumption, an opinion, which adds no solid value to the argument other than as a chat.I don’t understand what you mean. My first sentence or my second sentence?