AudioCircle
Industry Circles => Hollis Audio Labs => Topic started by: HAL on 3 May 2016, 11:48 am
-
When I was at RMAF2015, was able to attend the MQA discussion that Bob Stuart gave. It is a very interesting process to losslessly encode HiRez music using the original MLP idea, but using minimum phase apodising processing for improved sound quality. This was the discussion point.
Now that 2L has MQA encoded music samples to download, I was able to update my Meridian Explorer2 USB DAC with the latest firmware to do MQA decoding. The process works and the LED's on the unit indicate when MQA files are being decoded and to what level they are being decoded to.
The Explorer2 has both headphone output and line level output. I run the line level output to my iFi iCan headphone amp with the HiFiMan HE500 headphones. This setup sounds very good to me.
Have this working with the MS-3 Music Server and the results are very good indeed. Now 2L has he full length copies of some of the works that are MQA encoded available for purchase. Have bought a few of the classical recordings. Since the process is backward compatible with CD rates, they will also playback on standard DAC's, without the decoding to HiRez.
I will continue to follow the progress and see what happens.
-
It is interesting that a lot of the music servers are just announcing MQA for their streaming capabilities.
Since any HAL MS-1, MS-2 or MS-3 Music Servers can run the USB driver for the Meridian Explorer2 DAC, they could have started listening in February like I did with my MS-3 when the new MQA firmware was released with the 2L demo's and downloads.
-
An MQA article in this months AudioXpress magazine just arrived. More on technical details available until the patent is complete.
-
I find it interesting that after hearing the MQA process with the Meridian Explorer2 DAC that is sounds more like a live mic feed than straight recordings done at 24bit/192KHz like mine.
The minimum phase apodising filters used in both the A/D and D/A process sound very good, and after about 6 years of listening to minimum phase DAC's, my preferred reconstruction filter method for HiRez DAC's.
The part of the process that folks seem to be having issues with is the MLP portion of the system. Seems to work fine here.