NAD M50.2

Hi avlee,

I don't want to blow up this thread by jumping off topic, because I truly am interested in the 50.2.

But let me say this, I currently have my Perfectwave transport sitting one shelf directly above the Directstream transport. All I have to do is swap one end of a digital AES/EBU and I can compare transports. They Do Not sound the same. Not even close.
And starting another cable debate seems fruitless, but I offer that Anyone could hear the differences between a Fururech Digiflux and an Audioquest Diamond digital cable. They are like night and day.

And for who is interested, PS Audio is offering a trade-in program for cash credit toward a Directstream transport. My Perfectwave is headed to Colorado as a trade-in next week.

Ok.  I don't want to argue with you about cables.  It's really pointless. 

That being said, if there's a difference between the Perfectwave and Directstream, I have no idea what could be causing it.  I assume they both have the same transport mechanism, and I can't imagine that they do any sound processing, but who knows?  Perhaps the decoder in each product is making a difference, and if you say there's a difference, then there's a difference.

Either way, it's not likely that one is getting different *data* than the other.  It's how it's processed and sent to the DAC.  I don't have an aurender to compare to the M50.2, and I don't know the conversion steps (D->A->D?) but the M50.2 claims it does D->D.  If you accept that, then there is no extra analogue step required in the decoding due to the use of PWM.  Sound quality is really good, but there will always be someone who will tell you they like one over the other.  I would say it's subjective, but to me, it's very much good enough.

I received an email from NAD support.  They've said that "we are an airplay 2 partner, the details of the integration and compatibility are not yet available.  As for DSD, it's come up a number of times, however we cannot comment on the future of any upgrades.  The M50.2 does not do multichannel audio."

Two things to pull from this email:

1) Airplay is obviously being considered, but timeline is unknown.  Based on their other products (M17) I would assume DSD is not likely to come either.  This product is software driven, but there may be technical difficulties in how the data is piped to outputs.
2) I was wrong about MCH.  I don't know why I thought I read it supported multichannel.  Not super happy about that, but to be honest, I don't have any multichannel audio anyways.  That being said, if you want that feature, I would consider the Nimitra Fidelizer.  The Aurender is also stereo only.

I'll try an MQA file tonight.  I'm not sure how this is supposed to work, but as I understand it, either your DAC needs to have an MQA decoder or in this case, the M50.2 can decode the hi res FLAC directly.  In that case, I should see 24/88 or 24/96 or higher on my processor when I play a FLAC off of Tidal rather than CD quality (16/44).  I'll keep you posted.

I'm not an electronics engineer, so don't crucify me, Ok? Lol

But, from what I understand, CDs are PCM data, pulse code modulation. So the PCM datastream is not only digital steps, but also sampled at uniform intervals. Therefore the data must also include a clock somewhere. Even if the data itself is identical, the sampling timing is also critical.

I suspect, but can not prove, that its the clock or the timing that's responsible for the difference in sound between different units. I have three transports here, a PS Audio Perfectwave, a PS Audio Directstream, and an Esoteric K-03X, which can be used as a transport. The three units all sound different when feeding the exact same rest of the system. Which led me to wonder if the NAD might sound differently than, say, an Aurender playing the exact same rips or data.

PS Audio, on their website, states the betterment of sound from the Directstream over the Perfectwave is a result of better data timing, due to an improved memory buffer, and an ultra-low jitter fixed clock.

I also suspect its that timing aspect that results in different sound from different digital interconnects. Some are better at not messing up the timing than others.