Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion MQA - Related technology, products and music MQA Portable Equipment Options

Keeping it as simple as possible, it's possible to play the various 2L Files [including the MQA versions] thru a Phone and out thru the Explorer, thus bypassing the internal DAC of the phone... as well as the known OS limitations on resampling and max sample rates etc.

I've used an Android phone connected to a USB OTG cable to Explorer 2 to headphones [Shure SE535, SE846 and Sennheiser HD650's].

I also used an app called USB Audio Player Pro, which enables the bypass of the OS and Device DAC.

Another advantage of the above App is that it allows you to stream Tidal thru the App... thus also allowing you to bypass the OS and internal DAC... Tidal is the only app that it does this with.

And using this combo, I've played locally stored 2L Test Files of various Bit Depths and Sample rates, including MQA.

While playing the 2L files of 44, 96 and 192, I got the expected 1, 2 and 3 lights on the Explorer 2... and certainly the sound was much better than playing the same files thru e.g. PowerAmp thru the standard Headphone output... it certainly sounded like I was bypassing a lot of the hardware and software limitations.

It also sounded like the Apodizing was being properly engaged in the Explorer 2.

However, when playing the MQA files, I could not get the Blue light to turn on!! I tried several things and combinations, as well as maximising volume etc., etc. but I could not get it to light the Blue light... so I was obviously not bit-perfect... nor achieving the unfolding of the MQA files... but these MQA files still sounded very nice indeed. I need to spend more time experimenting to see if I can get full MQA playback and unfolding thru the above combo.

I also streamed Tidal tracks thru the above app... and again the sound was better than the native Tidal app to Headphone output.

I also played the Tidal app to the Explorer 2 [i.e. not using the USB Audio Pro Player]... and surprisingly, the Tidal app played thru the Explorer, when several other music apps would not even recognize the USB DAC.

However, when playing the obvious 16/44 files from Tidal, I was seeing all three lights of the Explorer 2 light up... indicating a 4x Output, which is possible on the phones I tried it with, but I will need to investigate more thoroughly... but the sound was certainly better than Tidal direct to Headphone output.

One downside to all of this is that powering the Explorer eats the phone's battery... and about 3-4 hours of playback will see a battery depleted... obviously a lot less than phone to headphone direct... but spare batteries and portable battery chargers are an easy way around this.

I didn't experiment on iPhones as I don't hold out much hope for the above work-arounds and apps working within the walled garden that is iOS... but I'd encourage others to try.

I realize that there is a lot of info in the above... and I just don't have the time to arrange it all more logically.

I just wanted to highlight that using the Explorer is possible with certain phones... as is bypassing the OS and Internal DAC's... and those interested should at least try it for themselves.

Any questions, please ask.

Great post. Many thanks.

Hi Ronnie

That sounds very interesting - are you able to comment on the SQ of the Android/Explorer 2 Combo v a Mac/PC Explorer 2 combo?

Cheers
Tom

Thanks Ronnie. Great start. I'll do some testing and post when all my kit is ready. I recently built some 1TB iPods to use in vehicles. These work very nicely with iPod friendly systems, plus charge simultaneously due to the direct connection.

My next plan is to use an external battery with E2 and iPod & iPhone to see what I get.

There other Digital Audion Players (DAPs) out there that I may also try in combo. Astell & Kern, Cowon Plenue, ..... Anyone utilize any of these or others?

John

Hi Tom

To be honest, I need to spend more time listening to the Phone / Explorer2 combo to arrive at a duly diligent conclusion... but forced to make a choice right now, I'd probably say that the Mac SSD / Explorer combo sounds a little better than the Phone / Explorer combo.

I mention SSD above, as I believe the elimination of a rapidly spinning magnet within the case helps to reduce RFI / EMI within a PC... and that helps with producing better sound quality.

It's also possible that as a Phone has all sorts of Radio Receivers / Transmitters within a small space [Wifi, Bluetooth, 2g, 3g, LTE, GPS, NFC etc], that RFI / EMI within that space could be higher than in the more "spacious" environment of a laptop.

But ultimately, if you know and like how your PC to Explorer sounds, then IMHO the Phone to Explorer combo is 'at worst' a small step behind... and after more critical listening, this may not even be true... jury's still out.


However, I consider them to be two separate use cases... I travel a lot... so a lot of trains, planes, taxi's and waiting... so I wanted to see if the Explorer would add anything to my portable audio requirements... i.e. easier to use a Phone / Explorer on a train or taxi than a PC / Explorer.

I had already been using the above USB Audio Player to bypass the Phone's DAC and OS... so I wanted to see what the Explorer would add... and I have to say that it did add to my listening pleasure... enough to overcome the "hassle" of using a 2nd phone, with spare batteries and battery packs etc... and leaving my primary phone free to do it normal duties.

The main purpose of my post was to encourage those who might be interested in improving their Portable Music solution to at least try this for themselves... some here will have an Android phone... and some of those will have an Explorer... thus spending £3 on a USB OTG cable.... and another £5 on the USB Audio app... or a Tenner total, is not a lot to spend on an experiment to see if their portable music source can be improved... and that the hassle is worth it to them.

So, to answer your question... PC / Explorer sounds a little better... but the Phone to Explorer sounds great as a portable audio solution, including Apodizing etc., etc.

Cheers

I can't see that a phone powering the DAC is optimal! Mind you, neither is the power from a PC or Mac - my experience with the Prime PSU showed that unambiguously.

True Joel, but the power output from my Phone is a relatively consistent 900mA, which isn't too bad... and would compare favourably with the output from a typical walwart type DC supply... and would be more consistent than from some PC's which can be very variable... and sometimes only supply 350-500mA.

I also think it's fair to say that once we leave our "main" listening rooms, we begin to make listening compromises [in fact, we even make compromises within those critical listening areas].

So all we're trying to do is reduce those compromises and find better ways to listen... even if we recognise that it's never going to sound like an 818v3 feeding D8kSE's.

Wow, the best part of 1 amp from a phone is both awesome and scary!

USB 3 Micro-B connection on a Note 3!!

Different phones with Qualcomm Quick Charge 2 & 3 can also output pretty high currents... but so many phones and so many specs, users have to try for themselves.

Having said that, the Data Sheet for the Explorer says:
which makes sense, when the Explorer is going to have to work with many PC's which only have USB 2... which is nominally 500mA... while 900mA can be capable of 900mA... and more in specific cases.

For iPhone users out there, there is some promise with the iPhone 7 allegedly eliminating the Headphone output altogether... and just going with Digital Audio out via the Lightning port... requiring new headphones etc., etc.

I still wouldn't be that confident about bypassing the typical OS limitations and Sample Rate restrictions that Apple seems to put on all its devices [bar Mac's] these days... so while Digital Out sounds appealing, it might be a forced resampling of everything to 16/48, just as it is on all their devices... time will tell.

I'm completely certain that Apple (or at least a part of Apple) is MQA-aware - it's simply not something that it can ignore or, if it does, it ignores at its potential peril. The question is whether or not Apple's left hand is talking to its right hand...

Undoubtedly aware of MQA... but I do think the term "Not Invented Here" was actually invented in Cupertino