- Thread Starter
- #141
I can but would have to run through the calibration and such which I have not done.It might be a bug, but maybe this is something you can see with measurement tools?
I can but would have to run through the calibration and such which I have not done.It might be a bug, but maybe this is something you can see with measurement tools?
Last call for measurements before I pack this unit.
The only AVR I use is for our main living room TV. There, it lives inside a cabinet so cannot generate heat. As such, I could not use this Denon AVR. What is there is a Pioneer AVR.Not exactly a measurement request, but I would be curious how you find this AVR running your personal HT system?
By the way -every time I come to ASR, it just gets more awesome!
I am glad it worked out for a win-win for all. But, there is still some explaining to do to figure out the root cause of the problem and whether this Denon unit is in the clear in all aspects...
Maybe you could test the RCA pre outs with ECO mode enabled in those models (like 6014, if I'm not wrong) which don't allow internal amplifier to be fully disabled.Most likely yes as the 3700 is not here yet.
I thought I tested the ECO mode and it didn't fix this issue. If it just lowers the voltage rail and switches when input level goes higher, then the problem will remain. But yes, I can test to be sure.Maybe you could test the RCA pre outs with ECO mode enabled in those models (like 6014, if I'm not wrong) which don't allow internal amplifier to be fully disabled.
I think the opposite would happen. Because the ECO mode lowers the supply voltage for the power amps, they would clip at a lower output voltage and the preamps also would distort at a lower output voltage.Maybe you could test the RCA pre outs with ECO mode enabled in those models (like 6014, if I'm not wrong) which don't allow internal amplifier to be fully disabled.
There could be a relationship between internal power amplifier heat/energy and the not-so-good output at 2v. Maybe ECO mode could help.
Your general point is correct but I am very careful with my grounding and have different options for that (e.g. Audio Precision by default is floating even with RCA unbalanced inputs). And there is no evidence of source noise in any of these measurements. We carefully analyzed this.Running things via a PC HDMI source can be tricky. I've got experience with three nvidia cards that all exhibit the same weird noise.
This is correct. And why this took so long to troubleshoot. It was only when I tested this on another AVR without this issue that I realized there is a problem here.
As I noted in the review, Denon engineering is investigating why this is occuring:
A normal mixer would apply a gain to every channel, perform the sum and handle potential overflow. If higher than input resolution is used for intermediate sum (which one hopes is the case), then dither is involved as is gain management in the AVR. Both or each may be responsible for the clipping and increase in noise floor.
The reason I am not losing sleep over this is because almost everyone using these AVRs uses it with more than a stereo pair of speakers. But yes, I hope a firmware fix is provided once it is confirmed to be the down mixing algorithm.
This is correct. And why this took so long to troubleshoot. It was only when I tested this on another AVR without this issue that I realized there is a problem here.
As I noted in the review, Denon engineering is investigating why this is occuring:
A normal mixer would apply a gain to every channel, perform the sum and handle potential overflow. If higher than input resolution is used for intermediate sum (which one hopes is the case), then dither is involved as is gain management in the AVR. Both or each may be responsible for the clipping and increase in noise floor.
The reason I am not losing sleep over this is because almost everyone using these AVRs uses it with more than a stereo pair of speakers. But yes, I hope a firmware fix is provided once it is confirmed to be the down mixing algorithm.
As you see, the best performance is around 1.1 volts which produces over 100 dB SINAD (dashboard uses 2 volt output so gets lower SINAD). With the amp turned on, the highest you can go is 1.4 volts before clipping occurs and performance drops precipitously. So make sure to look up the specifications for your external amplifier to see what its "sensitivity" is that generates its maximum power. If it is below 1.4 volts, then you are good.
May this phenomenon apply to other brand AVRs?Since vast majority of you are using AVRs with multiple channels enabled anyway, the issue that caused the problem should not be something you see
I'd echo everyone else who's said this: this really is sterling work and an excellent example of collaboration on both sides.
Also, with the greatest of respect, I've long thought the most conspicuous weakness with ASR tests is the lack of peer review. It's understandable of course, and that shouldn't be read as criticism of @amirm. Given this collaboration and dialogue it's reasonable to imply D&M reviews will be peer reviewed on their side, and differences discussed. That really will elevate the reliability of D&M review findings.
I wish other manufacturers would do the same and be as open. The Arcam response, if I recall, was the opposite (didn't they said something along the lines of "rookie errors"?).
I wonder, did they comment on the AV8805 review, which was tested with HDMI? It's difficult to see the argument for the 8805 in light of the Denon findings, unless the Denon's pre outs won't play nice with one's amp (mine's a NAD M27 - will have to check). The Denon has all the 8805's key features and more, plus would likely be just as reliable and bug-free.
Even if we consider all additional noise injected from various connection methods (HDMI, USB, Toslink), it is a job of the DAC to filter everything if it's properly implemented, am I wrong?
Why is it so difficult in this modern age to put proper DACs in AVRs?