DSD as PCM, is it Downsampling or a degradation?

Hello all, I hope I’m in the right place on the forum, as I have a question which I’m hoping the knowledgeable members on here could help me with regarding DSD playback as PCM.

I have a Puccini and uClock (I had a P8i before this) which I currently use with a Melco Music Library via USB. DSD files (.dsf) in my library present on the Puccini as DSD as opposed to 24/96 of flac & WAV etc

I recently got a Levinson 585.5 integrated amp which has a “precision link” DAC and phono stage onboard. Wishing to try the Levinson DAC, I connected the USB and a coax spdiff from the uClock. All was fine on these inputs until I selected a DSD album. It would not play as either “Melco Regular (the standard usual setting (Markerless or Native?) or DoP. PCM only output plays but presents on the Puccini as 24/44.1 and 44.1.Dsf on the Melco

Is this a downsample or degrade of the file quality. I’m perplexed as the 585.5 Is supposed to be DSD compatible (DSD128 I think) but none of the DSD filters are available to the PCM only output from the Melco. The only support advice I’ve received is just play as PCM

Obviously I’d be interested in opinions or advice thanks

The ML 585.5m is specified has having a DoP compatible input. So in theory if the Melco sends .dsf files to the ML they should replay as DSD.

The downsampling facility to PCM is switchable on Melcos ( see the front panel menu) but I am unsure if the Melco USB output is DoP compatible. The online specification suggests not but as it works with your Puccini maybe there was an update to add this.Perhaps you just need to uncheck the option. I use Melco in its role as NAS via the ethernet connection rather than as a streamer so my experience is therefore without any issues using .dsf files. So that leaves a question regarding the ML input. Although the DAC is DoP compatible is the USB input compatible or is the DoP compatibility assigned to another port? Please check.

Turning to your main question, yes downsampling DSD to PCM can have consequences especially if the PCM bit depth and sampling rate is low. Certainly a rate of 24/44.1 may be regarded as a downgrade from DSD and many DSD/PCM converters output a more reasonable 24/176.4 format.

Are we talking theory or is it audible and if audible is it significant? I leave that to you to decide.

Thanks for the input. To clarify a little if I can, my Melco is an N1A/2 the revision which added the dedicated USB output to DAC. This is capable of the full data output transmission which is how I use it for best sound quality. I don’t stream at all.

The Melco settings for output to DAC are standard, DoP, PCM only and Legacy. The selection is displayed on the Melco front screen. The Puccini locks to the first 3. I’ve never tried Legacy. But the Levinson will only play DSD on PCM only, other formats are fine ie flac/wav 44.1-192. I haven’t sat down and tried to do a comparison yet as I decided I would get used to the sound of the Puccini through the amp first as that’s how I’ve been listening as for years now.

I only understood recently what DoP actually is having re read the manual for the Puccini. A method of transmitting DSD data which is repacked and sent before being reconstituted into true DSD by the dac on receipt. I hope I got that bit right!

I normally play Puccini Balanced analogue out to the 585.5 or direct (as a pre) into an Audio Research power Amp

I’ve found a mention on Melco website that the original 585 was compatible but the 585.5 is not.

I was told that the DAC in the 585.5 was upgraded to the Precision Link DAC found in the related 519 player transport and 526 Pre amp. Of the 6 digital inputs It’s USB input alone features 4 DSD filters labelled 47k, 50k, 60k & 70k

There is an issue for me but I’m unsure if it’s compatibility between Melco and Levinson or if the latter has a fault. In any event I wanted to know if as I suspected that technically by playing as a 24/44.1 pcm was a degradation, which you confirm thank you.