NEWS: Meridian Releases The Explorer Pocket-Sized USB DAC - Page 10

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Originally Posted by MoonUnit 

 

They haven't disclosed which IC they're using for this, but it's probably an SMD device underneath the headphone output caps. I spent about a half hour trying to match the power specs with TI's current set of combo digitally controlled analog volume pots with headphone driving capabilities but couldn't figure out which one it was. It might be the latest part from Maxim.

Thanks.  I googled a bit and it seems that the USB standard for audio devices has control for external volume, but it is up to the DAC to decide how to use that information (i.e. analog or digital manipulation of volume in DAC).  So in my PC, I can control the headphone volume with both the volume control in foobar and with the volume control of the laptop but I have no idea if the laptop controls are changing the digital bits to the DAC or just the analog gain in the DAC or both.

With the logitech touch as the USB source, I have one volume control and at maximum volume it is the same level as when i configure it for fixed maximum output.  I assume this is all done digitally and that the logitech does not support external usb volume control.

I think my next step is to go to the squeezebox forum and ask the folks who created the usb-output app if they can enable the usb external volume control somehow.

One of the things I noted during hookup to my home system last night, is that there was a lot of low-level noise coming through the line.  I was using a slightly longer (cheapo) USB cable than the stock cable that came with the ME, as well as a short-length mini-to-mini adapter to the mini socket to RCA cable that runs to my preamp (DeHavilland Ultraverv).  I"ve got an Audioquest Carbon USB on order (supposed to be here later today).  Hopefully the higher quality (better shielded) cable and some experimentation with cable routing will help clear this up.  Most of my listening is fairly near-field, so the noise is obvious during low-level musical passages.  Overall SQ out of the ME continues to be exemplary.  No fatigue, even at high listening levels.  24/192 Ellington '65 sounded great--clean, individual instruments discernable with no smearing, and a good sense of soundstage depth. 

Mine arrived yesterday and I'm experiencing noise issues as well with the Meridian's analog out connected to an external amp. Looks like it's time to play this weekend to see what the problem might be.

Quote:

Originally Posted by dpippel 

Mine arrived yesterday and I'm experiencing noise issues as well with the Meridian's analog out connected to an external amp. Looks like it's time to play this weekend to see what the problem might be.

I am not hearing any noise?  Would you please elaborate.

http://www.audiostream.com/content/meridian-explorer-usb-dac

I purchased the lifetime gold version of MediaMonkey a few years ago and decided to install it on my a fresh format instead of foobar.  I enabled that wasapi option however I have not used MM much and was wondering if I should change any wasapi settings.

Out of the box this thing is very impressive, the top end will hopefully settle down as others have noted.

Originally Posted by wfranklin 

One of the things I noted during hookup to my home system last night, is that there was a lot of low-level noise coming through the line. 

Originally Posted by dpippel 

Mine arrived yesterday and I'm experiencing noise issues as well with the Meridian's analog out connected to an external amp. Looks like it's time to play this weekend to see what the problem might be.

Is the noise constant in pitch and volume, or does it vary with activity on the PC or any other factor? Do you also hear the noise with cans directly connected to the Meridian's headphone output jack?

Too bad there isn't an option for a black ME.  The ME pairs very nice with the portaphile 627 and the Heir Audio 8.A.  After some burn in I will A-B the ME with the LX however I think the LX will be going back.

My serial number is MA006 and the last digit is a letter.

Quote:

Originally Posted by HiFiGuy528 

All business packaging. It may make an appearance at the SF Head-Fi meet this Sunday. Maybe....

Quote:

Originally Posted by Bostonears 

 

Is the noise constant in pitch and volume, or does it vary with activity on the PC or any other factor? Do you also hear the noise with cans directly connected to the Meridian's headphone output jack?

It is independent of music volume; with no music playing (but preamp volume at listening level), there is noise on the line.  I tried playing with cable positioning a bit, but was constrained by cable length.  The ME was located just behind the screen of my laptop, and just in front of the tube preamp.  Amazon sent me the wrong damn cable (ordered A to mini-B, Amazon stock label on box indicated A to mini-B; cable is A to B.  Time to head to BestBuy to see what they've got in stock (if anything). I think the noise issue can be handled by using better cables and keeping the routing away from the laptop.  Note that I don't have this problem at all when listening to headphones; this is strictly when multiple cables are being used between the laptop and the preamp (laptop - USB - ME - mini phone plug to mini phone plug cable - mini phone socket to RCA - preamp).  As I mentioned earlier, these were cheap (not audiophile grade) cables.

Quote:

Originally Posted by Poimandres 

I am not hearing any noise?  Would you please elaborate.

Quote:

Originally Posted by Bostonears 

 

Is the noise constant in pitch and volume, or does it vary with activity on the PC or any other factor? Do you also hear the noise with cans directly connected to the Meridian's headphone output jack?

The noise is constant, dirty background static that is most apparent with no music playing and the volume pot on the amp turned up beyond normal listening levels. Yes, it does increase with volume. I currently have an Arcam rDAC (USB) and CIAudio VDA1 (Toslink) on my desk as well and neither of them exhibit the problem. Two different well-made 3.5mm to stereo cables between the DAC and the amp do not change the situation and neither does switching USB cables or USB ports. I even plugged the Meridian into a powered USB hub. Same result. It's possible that I have a defective unit, but as I mentioned earlier I haven't had the time to thoroughly test the situation. That happens tomorrow.

And the amp turned up beyond normal listening levels?  Have you tried directly into an amp from the lineout?  I hear no noise but only use the lineout not the headphone jack.

Originally Posted by wfranklin 

It is independent of music volume; with no music playing (but preamp volume at listening level), there is noise on the line.  I tried playing with cable positioning a bit, but was constrained by cable length.  The ME was located just behind the screen of my laptop, and just in front of the tube preamp.  Amazon sent me the wrong damn cable (ordered A to mini-B, Amazon stock label on box indicated A to mini-B; cable is A to B.  Time to head to BestBuy to see what they've got in stock (if anything). I think the noise issue can be handled by using better cables and keeping the routing away from the laptop.  Note that I don't have this problem at all when listening to headphones; this is strictly when multiple cables are being used between the laptop and the preamp (laptop - USB - ME - mini phone plug to mini phone plug cable - mini phone socket to RCA - preamp).  As I mentioned earlier, these were cheap (not audiophile grade) cables.

As you surmised, that's probably the interconnects between the Meridian and the preamp picking EMI from a poorly shielded USB cable or from the laptop itself.

Originally Posted by dpippel 

 

The noise is constant, dirty background static that is most apparent with no music playing and the volume pot on the amp turned up beyond normal listening levels. Yes, it does increase with volume. I currently have an Arcam rDAC (USB) and CIAudio VDA1 (Toslink) on my desk as well and neither of them exhibit the problem. Two different well-made 3.5mm to stereo cables between the DAC and the amp do not change the situation and neither does switching USB cables or USB ports. I even plugged the Meridian into a powered USB hub. Same result. It's possible that I have a defective unit, but as I mentioned earlier I haven't had the time to thoroughly test the situation. That happens tomorrow.

Sounds like it merits a call to Meridian.