Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion HiFi & HT Chat Upsampling and skinning the proverbial cat

I guess there could be several possible factors that may contribute to Toslink not being my preferred interface based on what I hear in my setup. Some may be related to rendering software/OS options that are not available via SPDIF and some to the Toslink interface itself i.e. higher jitter. There are also many variables with regard to Mac hardware options being used and OSx configuration that can also have an impact in addition to the setup of the audio rendering software itself.

That said I also find that the difference can be influenced by the type of material and volume level. YMMV

Avi

Hi Gary
Both Optical and Coax are forms of SPDIF Connections...........and as Meridian has shown, both are fine for connecting components.......some people have a preference for Coax over Optical (as do I) but both can function very well

The difference here is that we are talking about Optical out of a Mac (or any computer for that matter)

As you've seen from the previous posts, when a Computer is the "Master" of sending the PCM Data Stream over SPDIF, then that can lead to reasonably significant amounts of Jitter.......sometimes up to 4,500ps........the reason being is that a Computer has a lot going on within the OS (even when Idling), and as a result, Jitter will occur

The major difference with an Async USB Device is that the Async Device controls the Rate of PCM Data from the Computer.......i.e. the Computer is now the "Slave" and the Async device is the "Master"

Net result is that VERY low levels of Output Jitter.......measured as 185ps by Stereophile and 75ps by Computer Audiophile

You'll notice above that I have called the Halide Design Bridge a "Device", as I believe that it is best to think of it like a "Black Box for Source Jitter Reduction"..........which just so happens to look like a Cable, for convenience

The Halide Design Bridge is an Async USB Device......and as such is far more than just an Optical or Coax Cable

By the way, it's also worth reading up on the Wavelength and Ayre QB9 USB, as both of these use the same Aysnc USB connectivity

Async USB is the future of Device Connectivity IMHO........along with IP Packets over Ethernet......both are Two Way and as a result are able to dramatically reduce / eliminate Jitter levels at Outputs and Inputs

Hi Gary
On a quick look at the Halide Design Online Store, they offer a 60-day Money Back guarantee

Why not buy one and try it against your friends Optical cables etc.

If you don't like the results, you can always send it back

Just a thought

That 60 day money back guarantee does look like an entertaining idea. Thanks guys this thread had perfect timing for me.

Gary

Hi Gary
If you are running trials over the weekend, make sure you download the Pure Music Player as well

This comes as 15 day free trial......and would be worth testing in conjunction with the Cables and Async USB etc

Enable "Memory Play" and "Hog Mode" in the Settings

It just sits on top of iTunes, so there's no Importing or anything else...........it simply takes over from iTunes when you press the iTunes Play button

@ Ronnie, I read a piece by Art Dudley in the july issue of Stereophile comparing "Pure Music", "Amarra", and "Decibel". Dudley seemed to like all of them. When I was at T.H.E. Show and CES in January I saw a pretty impressive demo by Amarra. Other than price is there any other reason to prefer "Pure Music"?

The Stereophile review was of an earlier version of Pure Music i.e. 1.74. I also believe Art didn't setup the software and used the vanilla settings which may produce less than optimal results. Pure Music 1.8 sounds noticeably different in my system to 1.74. I also have Amarra but for my tastes it's not my go to solution.

Also bear in mind how the hardware, OS and rendering software is setup can affect the audio. I found the software products can sound different and personal taste plays a role as to what "sounds best". I've also found "best" may change depending on the type of material.

The highest performance output setting from Amarra requires the use of Amarra play lists rather than using iTunes front end to browse, select and play etc. Normally Amarra uses iTunes as the front end running in "ghost" mode i.e. both iTunes and Amarra are playing the music but iTunes is muted. This causes greater CPU activity and also limits certain features i.e. memory based playback. Pure Music only uses iTunes as a database and doesn't operate "ghost" playback like Amarra. Also Amarra doesn't support integer output and this offered a noticeable improvement in my setup. There are also other differences in features between the products that may be more or less important.

Most audio rendering software is available for free trial so it's relatively easy to listen first hand. The only downside is knowing enough about the computer to get the best results.

Avii

This is a great post. Just about everything that was bothering me has been covered. I have PM'd a number of people to get advice and now its all collated in one place. Ronnie has been particularly helpful and patient with regards to answering what to some people are going to be obvious questions.

I vote we make this a sticky.

By the way. The updated OSX (Lion) is expected any time soon, in fact macrumors.com are thinking it will be this week. With it will be an updated MacMini. Hence Im holding out from actually buying all this stuff, but Im going MacMini, Halide Bridge and Pure Music with Apple Remote on the iPad.

An update from the dark side...

Plan A is flawed. The software package "Wave Editor" by Audiofile.com can not batch process ie it can only handle a single track at a time... life's too short!

Their alternative "Sample manager 3.2" can batch process, but can only export in FLAC format, not import. Again I feel life's too short to convert all the FLAC to WAV etc

Ho hum...

On the subject of life's too short, have you actually just sat and listened to the C15?

I'm not sure if you're exploring all these options based on your listening experience or just theories about what it does/ doesn't/should/shouldn't do etc.

Just curious....

Hi Nick - yes, I've listened, hence the desire to try to skin the cat a different way. My opinions are subjective and therefore of little use to others - suffice to say I've heard better from my system (3D soundstage/dynamics)

One of the CDs I use for assessing the system is the Chesky "The Ultimate Demonstration Disc" - highly recommended and available from Amazon.co.uk

This has absolutely been my experience.

At work I have a MacBook Pro 2010 connected via optical to a Firestone Fubar IV DAC and a pair of Sennheiser HD555 cans ... and in this setup, Fidelia is a vastly superior piece of player software than iTunes/Pure Music. Instruments are better defined, the top end is less muddied, imaging is better. Wow, I thought, those iZotope algorithms really do what they say on the tin, even if a dual-core Core i7 CPU is now running at around 30% utilization to make it work.

But on the home system, it's a whole different story. Using a Mac Pro connected to an MPMax 221 via optical and then to DSP5200s, Fidelia sounds recessed, extremely polite, quite un-involving and the bass response never quite arrives. iTunes/Pure Music is vastly better in the home system.

So next step is to try out one of those Halide Bridge gadgets and see how an async USB connection improves matters in both systems. As Avii says, YMMV.