Volume Clipping on Streaming with HEOS

[GSHastings]

I have a strange problem. I was using my new Marantz PM7000N, using the HEOS function to stream music from Amazon, and was recording it using the "Recorder" output feeding to my computer.

I noticed that the music was being clipped, but not because the volume was set too high at the recording software. It didn't matter how low the volume was set at the recording software, the music was still being clipped. Loud passages were completely clipped, even if the level was set very low in the recording software. The volume at the "Recorder" output on the Marantz is set a some spefic Line Level, and can't be changed by the user.

I did some tests to try to determine where the clipping was occurring.

I have been able to confirm that the clipping is not happening by the circuitry to the "Recorder" output on the Marantz amp. I can play the same music from various other inputs, and it isn't getting clipped.

I've been able to confirm that the clipping is not being done by the Marantz's DAC. I can play the same music from a USB drive plugged into the Marantz, no clipping.

And I can play the same music from a USB drive plugged into my router, using the router as a Media Server, which is connected to the Marantz with 1000 Mbps Ethernet. So that eliminates the network input as the source of the problem.

The problem only occurs when I use the HEOS app on my iPad, and I can play the same music from different streaming services, and it clips every time.

As best I can tell, the HEOS app is just controlling the Marantz, selecting music sources, selecting songs, etc. I'm not sure how it could be causing the music to get clipped.

Attached are 2 screenshot showing the waveform as recorded from a USB plugged into the Marantz, and as recorded streaming from Amazon using the HEOS app on my iPad to control the Marantz.

Any ideas what could be causing this?

 

[Quazar]

Is the restorer function on or off?

 

[GSHastings]

Is the restorer function on or off?

I wasn't familiar with what you are referring to, so looked it up online. That appears to be a function that is available on Denon hardware, but the Marantz doesn't have that feature.

It seems like that function pertains to lossy compression formats, and I'm using lossless format FLAC.

I'm beginning to think it might be some kind of a dynamic range mismatch issue. Perhaps the music is at a high bit depth initially, and at some point a change to a lower bit depth lops off the top of the dynamic range.

The Marantz is capable of dealing with 24bit/192Hz streaming formats.

I'll have to research this some more to see if it is a possible cause.

 

[GSHastings]

After extensive testing, I think I have narrowed the problem down to my computer's sound system.

And that's odd, because I'm using an analog Line-In input, coming from the analog "Recorder" output on my Marantz. It seems that certain sources into the Marantz put out a volume on the "Recorder" output that somehow swamps the Line-In input on the computer.

 

[GSHastings]

I am now able to confirm that it was the computer's sound system. I installed a SoundBlaster Audigy Fx sound card, and that fixed the problem...no clipping.

I'm a little disappointed with that result, because my computer is a pretty good quality Asus, only about 1 1/2 years old...and they specifically mention the "Quality" of the sound components on the board. But, somehow, the Line Level input coming from the Marantz has a dynamic range that exceeds the capabilities of the sound system on my PC.