NEWS: Meridian Releases The Explorer Pocket-Sized USB DAC - Page 27

My Explorer got delivered today.. liking it quite a bit so far.  I couldn't get it to work via OTG (USB Audio out) with my Galaxy S3 (Verizon, stock "TouchWiz" rom).  I'm currently listening with the Sony XBA-30 IEM (which has a ridiculously low 12 ohm impedance rating) and I don't sense any damping/impedance matching issues.  In fact, this phone's synergy with the ME seems quite good.  Clean, detailed, lively, organic.. with a hint of colorful contrast.

Edited by FlySweep - 2/27/13 at 11:03pm

Flysweep, at 50ohms output impedance, you're no longer listening to the xba-30 but more like xba-1... Mind you, this may be just what the xba-3 needs to tame down the highs a bit (would have to compare the response curves through say an iphone and the explorer to tell the impact, it is dependent on the passive filter before the ba drivers. Variations exceeding 4-5dB across the range, like purrin showed for another headphone, are to be expected though...

 

Arnaud

I feel that any so called "dirty" usb power would be negligible at best on any modern computer.

And also "dirty power" would be an anologue domain anyway when we are talking digital. ..
A super high quality DAC with on board clock control so there can be no affect to the digital domain from any dirty power,
not to mention the voltage tolerances that is inherent to these chips they can handle,
as well as the superior design of the company making it..
So I seriously doubt the majority of owners will ever be able to distinguish any benefit of using any power cleaner .
I would say rare cases of old hardware and a simple upgrade of the power supply would remedy it.
Just look at any laptop power supply just how large it is and if it were not enough then the laptop would surely not be able to last.
Power cleaners to me are an unnecessary fad.
When all they need is a good power supply from the beginning.
Edited by Maxx134 - 2/27/13 at 9:41pm

Dirty usb power is indeed an issue, although more often than not if you're on a laptop this can be ameliorated by unplugging the computer.

 

In the case where you're stuck with it and your usb power is bad... then there's really no point to using a usb device. If you're still trying to keep it portable, then either get a laptop with better power or get a usb/spdif bridge and plug into a battery powered dac. It's not a perfect solution, but better than hauling around an extra power brick/device. 

About the output impedance, seeing the rest of his review I wouldnt trust him about his measurements! He completly bashed the product and some days later said that it could be possible he got a defective unit.

I guess we are all deaf and this genius is the king of the reviewers...

 

Good points all around.  I've spent about two weeks with the XBA-30 (used daily) so I'm pretty well attuned to the fq signature & sound.  The XBA-30's bass & treble.. the latter which is already quite smooth.. didn't sound particularly more dull via the ME.  That kind of thing would've jumped out to me pretty quickly as I like me my trebles.  I'll compare with the UHA & iPhone 4 to see if I hear any difference.  Obviously my comparison will be purely subjective (and fairly rudimentary), but I suppose I should hear a fairly distinguishable change in sound from when driven from two amps with significantly different OI.

 

Do we have any official confirmation on the ME's output impedance?  I saw the "50 ohm" figure floating around.. but wasn't sure if it was confirmed.

Edited by FlySweep - 2/27/13 at 10:38pm

what are you smoking bro, the output Z was also confirmed by Tyll using a different unit =)

 

http://www.head-fi.org/t/652910/meridian-explorer-dac-amp-stream-of-consciousness-review-warning-not-good/45#post_9209492

Thanks, dyaems - that's what I was looking for. MoonUnit's summary below Tyll's measurements sums up the downside of those figures (bolding is mine): 

 

It means that the amp essentially applies a headphone-dependent tone control (equalization curve) to the sound you hear. In many cases, this will mean the sound is more "midrangey" and with rolled off highs than an amp that is accurate. The effect will be more pronounced on low and medium impedance headphones, and most pronounced on low impedance IEMs with multiple drivers and crossover networks. Also, it means that the bass will be poorly damped (wooly instead of tight). Some people perceive this as a more "bodacious" bass that they find pleasing, but it is not particularly accurate.

 

Voldemort and others leapt on the Fiio E9 for this exact 'crime', and it has been a noose around the E9's neck ever since. Fiio's budget blaster measured well on almost everything else on V's list. but high output impedance was thrown up as a roadblock to every potential purchaser on HF from that point forward. It will be interesting to see how the ME fares, particularly given that it would seem even more suited to IEM use than the brick-like E9. 

 

How about using the USB Audio Recorder PRO app available on the Google Play store ? 

https://play.google.com/store/search?q=+USB+Audio+Recorder+PRO
This app doesn't use the Samsung-implemented USB audio driver. It includes its own USB audio function, more tolerant.

 

 

would this program enable most portable dac to work with android phones? is the HRT micro streamer simply plug and play, and can be powered from the Samsung gs3?

 

In my case, it wasn't so much the highs but the bass that caused me the most headache pairing my xba-3 to an amp. It started with my tomahawk, an amp supposidly dedicated for iems, that did (much) worse than my iPhone in terms of bass control. I tried multiple portable amps at a local meet and, as a I recall, only the O2 did make the phone sound better than unamped (and another one from germany that shigzeo brought but I don't recall the name, was too expensive anyway).

 

Anyhow, I came away being  a happy camper with just my iPhone 4 and it's 1 Ohm zout to drive my xba-3s... I'd be surprising the explorer doesn't significantly affect your xba-30 response... 

 

 

Purrins review is a bit melodramatic for sure, but since his measurements are confirmed by Tyll, whom I trust in that regard, I guess we'll have to face the fact that the headphone out is not an optimal match for low-impedance headphones... I'm quite content with the Explorer feeding a Lake People amp and have no problems with its own headphone out when using it in the office.

 

Nevertheless I'd like to understand that design decision as I don't think Meridian did that by accident. As Tyll mentioned they might want to limit current output due to USB power limitations.

This is pretty interesting.

 

I accused the DF of having high output impedance (nothing as high as this, but suspected ~10ohms) because of how I perceived that to be overly warm... mostly due to the nature of the bass.  Granted I don't know if I'd heard what high output impedance sounded like, it was just my assessment born from using a variety of < 50 ohm headphones and IEMS (all dynamic down to 16 ohms) on it vs. an ODAC/O2 combo, an E17, and my MBA headphone out, all noted to have < 2 ohm output.  They all just sounded more like each other than they sounded like the DF.  Gordon Rankin finally stepped in after I reported the results a head-fi member made on CA and corrected the method and claimed a sub 1 ohm on it.  Then I chalked it up to improper burn-in, or perhaps a smoother sound due to the async implementation.  It's all there in the DF thread,  plenty of people were clamoring for measurements but I believe I was the first who thought he 'heard it'.  Some people thought I was a bit crazy or my hearing is off, which I guess perhaps it is.

 

With the ME, I just didn't detect it and didn't even suspect it.  Again this came from bouncing it against the headphone out in my MBA (which Voldemort measured and claim it was perhaps the best headphone out on a laptop he'd seen) the DF using a 16 ohm dynamic IEM.  In this case I felt the frequency response has more in common with the MBA than the DF, that it's certainly leaner.  

 

Yesterday I took delivery of a FitEar TG!334 and only tried it on the ME and MBA headphone out, my first multi-crossover BA IEM.  To me they sounded quite similar in frequency response.  I have yet to try the DF as I let a friend borrow it but I'll try to get it back today and see how it fares with the 334.  Nothing really to add here besides this - I came into purchasing both the DF and ME with relatively high expectations based on reviews I'd read beforehand, and certainly had the expectation the ME was leaner based on those reviews.  I do realize there were some comments here that claimed otherwise but that's not the way I hear it, then again I may have really succumed to expectation bias here in a pretty grand way.  And I esp. thought Purrin wrote a satire piece.

 

The weirdest thing is Meridian publishes that 16 ohm spec for max output.  It's almost perverse they would do that, as clearly this is not designed to drive something like that.

Edited by bobeau - 2/28/13 at 5:08am

I assume we would need a USB OTG cable to use the microstreamer is this correct?