2. digital
  3. 146559-46

Need to under stand Asynchronous USB

So I just got a Marantz ND 8006 Network CD player. Im using it as a network player and CD transport  and I output digital to my NAD M51 DAC. I’m using my IPad to stream TIDAL and that works tip top. However, it’s the USB inputs that concern me. I have a choice of a front connection and a rear USB DAC connection. 

Couple questions:

1. The USB DAC input is for a Mac or PC hook up, but is there any other way to use an input like this?  Does it have to come from a computer or can a USB hard drive work with an input like this?
2. More importantly the front USB input is NOT asynchronous.  I think they make a reclocker I can put in between the USB and the unit. My question is do they make a USB hard drive with a built in reclocker with a good amount of hard drive space?

this is all new to me, so any help would be appreciated. 
last_lemming
stevecham
3,340 posts
 
1) You can use a USB flash drive, iPod or other portable player.
2) Asynchronus is what you want. The DAC being fed by the input reclocks the data and this is the ideal.
last_lemming OP
639 posts
 
Item 2) you mention, does that mean my DAC does the reclocking and I don’t need an external reclocker?
motokokusanagi
189 posts
 
I have the M51. The USB - the type B - input is async from XMOS. The DAC uses its own clocks. However, it’s been widely agreed from reviews and users (and I concur, also) USB is not the best input for it rather than AES. I tried various USB decrappifiers from iFi and linear power supplies, as well as various coaxes but they didn’t swing that judgment.

I use a Yellowtec PUC2 Lite which is a USB-AES converter and that’s the best sound I get from the M51. Sound is muscular and detailed.

It seems to take a great deal of extraneous gear for USB to perform optimally (reclockers, isolators, power supplies, e.g. SOTM or Uptone kind of thing), by which point you could have gotten a better DAC period!

The other USB - type A - input you’re talking about implies using a USB flash drive for local playback. That’s not what the other USB jack is for - rather it’s for updating the firmware (1.39 is best for the M51 rev1!)

If you want to use a computer and/or network storage as a front-end, then you might want to look at a streamer (e.g. Bluesound, Auralic) with any kind of digital output. It can be USB, optical, coax, even HDMI, or AES, but as I said, the M51 likes AES the best. Or indeed track down a Yellowtec PUC2 lite + USB streamer.
last_lemming OP
639 posts
 
Moto. I’m feeding the DAC info through the Marantz.

I guess im still a little confused. I’m runner no a standard thumb drive into the Marantz witch then sends it via coax digital out to the coax in of the DAC (nad m51).

Do I still need a reclocker or something?
erik_squires
16,138 posts
 
Either USB input will have equivalent performance.

Asynchronous USB refers to the DAC being the conductor in the communication. The PC/Mac software or whatever doles out data as the DAC requests it. So, it’s a cooperative arrangement. The PC/Mac picks what to play, reads it and sends it down to the DAC, but the DAC remains in control of the metronome.

The front USB connection is for media devices, including a hard drive. Since the Marantz is also acting as the player software, the idea of asynchronous is kind of irrelevant.

In both cases the DAC will be in charge of the metronome.

Now, if you use S/PDIF via optical or coax this no longer happens. Then the source device owns the clock, and the DAC better keep up.


More to discover