Distortion with Ultra line out to B&K power amp

[RWB]

Update;

After trying everything I could think of including the advice from others in this thread and from Wiim I ordered a replacement and it's doing the same thing. My assumption is the Wiim Ultra's handling of analogue signals is limited and that's the issue. I assume the line-in connections pass through digital processing in the Ultra and in doing so the Ultra's handling of wide dynamic range analogue signals is just not up to dealing with the transients of well recorded CD's. Those same CD's, with all settings on the Ultra the same, sound great when coming in through the optical-in and using the DAC in the Ultra. There's also momentary drop-outs of the sound when the CD plays through the line-in as if there's an issue with buffer capacity. I'm not an EE so just guessing here but maybe the amount of line-in data from the large transients of a well recorded wide dynamic range CD overwhelms the buffer and that's where the distortion occurs because CD's without the extensive DR seem to play fine.

Maybe it's just that for $329 this is the achilles heal? Maybe this was a compromise in the design decided on the basis that most applications for the Ultra will be with digital source material?

I still think it's a great device for the money and this is a bit of a disappointment but not a deal killer. In my limited listening experience so far I believe using the DAC in the Ultra provides a bit more detail and clarity compared to the DAC in the old Rotel so maybe a win in the end. Now I'm considering replacing the 25 year old Rotel with a new CD player that has an optical out so I can eliminate the Prozor coax to optical converter.

Opinions on a single disk CD player in the $500~$600 range would be welcome. I'm looking at the Denon DCD-900NE and the Marantz CD-6007 as both have optical out connections.

​

 

[mkp1969]

Update;

After trying everything I could think of including the advice from others in this thread and from Wiim I ordered a replacement and it's doing the same thing. My assumption is the Wiim Ultra's handling of analogue signals is limited and that's the issue. I assume the line-in connections pass through digital processing in the Ultra and in doing so the Ultra's handling of wide dynamic range analogue signals is just not up to dealing with the transients of well recorded CD's. Those same CD's, with all settings on the Ultra the same, sound great when coming in through the optical-in and using the DAC in the Ultra. There's also momentary drop-outs of the sound when the CD plays through the line-in as if there's an issue with buffer capacity. I'm not an EE so just guessing here but maybe the amount of line-in data from the large transients of a well recorded wide dynamic range CD overwhelms the buffer and that's where the distortion occurs because CD's without the extensive DR seem to play fine.

Maybe it's just that for $329 this is the achilles heal? Maybe this was a compromise in the design decided on the basis that most applications for the Ultra will be with digital source material?

I still think it's a great device for the money and this is a bit of a disappointment but not a deal killer. In my limited listening experience so far I believe using the DAC in the Ultra provides a bit more detail and clarity compared to the DAC in the old Rotel so maybe a win in the end. Now I'm considering replacing the 25 year old Rotel with a new CD player that has an optical out so I can eliminate the Prozor coax to optical converter.

Opinions on a single disk CD player in the $500~$600 range would be welcome. I'm looking at the Denon DCD-900NE and the Marantz CD-6007 as both have optical out connections

 

[mkp1969]

I would consider the SMSL PL100 which is a lot of bang for your buck at around $100. I've had one for a few weeks and can honestly say that, as a transport or a full on player, it's up there with some of the best mid range offerings the 1990s had.
It's also very small. The only caveat is that you need to source your own 5V 2.4A PSU for it but an off the shelf Raspberry Pi 5 PSU does the job perfectly.

 

[RWB]

I would consider the SMSL PL100 which is a lot of bang for your buck at around $100. I've had one for a few weeks and can honestly say that, as a transport or a full on player, it's up there with some of the best mid range offerings the 1990s had.
It's also very small. The only caveat is that you need to source your own 5V 2.4A PSU for it but an off the shelf Raspberry Pi 5 PSU does the job perfectly.

Thanks and I'll check it out.

 

[RWB]

One more update;

I posted this issue on two different YouTube channels where the Wiim Ultra was reviewed by people with much more knowledge and experience than I in this area. It was confirmed in the responses that the line-in signal does pass through an ADC for digital processing such as EQ and then through the DAC for output. When using the analog line-out from my Rotel the CD data is converted from digital to analog in the Rotel then back to digital in the Ultra and again to analog for output to the power amp. It would seem likely this is too many steps in the handling of the signal and might explain why the problem doesn't exist using the digital out from the Rotel and the result sounds better.

I thought this might be of interest to others.