How to go from Apple TV digital out to MTRX?

[ntp-jl]

Originally Posted by JFreak

Are you suggesting MTRX cannot lock to external clock source? This scenario is simply playback from ATV not using it in a session...

NO, that is not what I am suggesting. The MTRX can lock to all kinds of external clock sources, including word clock, video, AES, Dante/AES67 and MADI.

What I am pointing out, is that the Apple TV can not be locked to an external source. This means that the digital signal from the Apple TV can not be synchronized with the clock of the MTRX, therefore you will have clicks in the sound. The only way to prevent those clicks is to use a sample rate converter which can compensate for the slight difference there may be in the clock of the Apple TV and the clock of the MTRX.

[JFreak]

MTRX can lock to ATV, then there is no problem.

[SomeOtherGuy]

Originally Posted by ntp-jl

The fundamental principle in any digital connection (AES, MADI, etc.) between two devices is that the two devices must be synchronized to the same clock. If they are not synchronized, you will have clicks and drop-outs in the sound.

In this particular case, the Apple TV is the source and the MTRX is the receiving device. The Apple TV and the MTRX must therefore be synchronized to the same clock, otherwise there will be clicks in the sound. Since the Apple TV does not have a sync input (Word clock, AES input or similar), there is no way that the Apple TV and the MTRX can be synchronized.

The only alternative to this is to use a sample rate converter (SRC) between the Apple TV and the MTRX. That way the Apple TV does not need to be synchronized to the MTRX. None of the devices that have been suggested in the thread have SRC, but are only format converters.

My suggestion is to use an AES card in the MTRX. The AES card can do SRC on the inputs and it should therefore work fine. The AES inputs on the MTRX base unit do not have SRC so they can not be used. As the AES card is cheaper than an analog input card, you may want to go that way instead. If you do that, then please remember to order a break-out cable for the AES card as it has a special high-density connector.

Alternatively you could maybe find a format converter with built-in SRC and the built-in AES.

Hi Jan - I already have the AES optional card installed in my unit, and I was using it for this setup. I run the MTRX at 24/48 and as far as I know the Apple TV is at 16/48. (The ATV may be at 44, it's hard to tell, but I can't run my studio at 44.)

I don't want to use the inferior internal clock of the Apple TV to control the MTRX, so I don't see another way other than analog. I thought about trying this:

https://www.sweetwater.com/store/det...hoC-EQQAvD_BwE

In the end it's okay if my only alternative is analog. The Apple TV is a sideshow after all. I was just hoping it could be connected digitally without it being the master.

Thanks for your input here.

[Delta Music Belgium]

I'm using a bunch of Behringer SRC2496 to connect Toslink equipped devices to AES/EBU inputs on AVID HD I/O's. These boxes accept WC and re-sync (and S/R convert if you want) the digital input to AES/EBU (and S/P DIF coaxial or optical). I use these boxes as digital Swiss army knives converting and splitting digital signals and I also use them as digital input selectors.

Maybe this could be a solution? Just send the optical output from the HOSA to the SRC2496, provide it with WC from your MTRX and send this re-synced signal by AES/EBU to the MTRX.

They are cheap and I never had any problems with them. I don't use the 24 bit 96 kHz AD/DA stages, I just use the digital inputs and outputs on the boxes.

[JFreak]

Originally Posted by Delta Music Belgium

I'm using a bunch of Behringer SRC2496

This is actuall one of the very few Behringer boxes I have zero problem with. Other products, oh please...

[SomeOtherGuy]

Darryl - yes, that should work, but I don't want the MTRX to be master-clocked by a consumer audio device such as the Apple TV. My guess is that the Apple TV's internal clock is nowhere near the quality of the MTRX. It's a Catch-22!

As much as I don't like their brand philosophy the Behringer device looks like it'd get the job done though.

[JFreak]

Originally Posted by SomeOtherGuy

I don't want the MTRX to be master-clocked by a consumer audio device such as the Apple TV. My guess is that the Apple TV's internal clock is nowhere near the quality of the MTRX

Usually that is just sensible thinking.. but correct me if I'm lost but wasn't the original trouble to just get PLAYBACK from ATV

[BScout]

Originally Posted by SomeOtherGuy

Darryl - yes, that should work, but I don't want the MTRX to be master-clocked by a consumer audio device such as the Apple TV. My guess is that the Apple TV's internal clock is nowhere near the quality of the MTRX. It's a Catch-22!

As much as I don't like their brand philosophy the Behringer device looks like it'd get the job done though.

The MTRX never runs on any clock but its own internal. What it does do is reference external clocks. There is a difference. It buffers the incoming clock to find the sample rate and then matches it internally.

(I use an RME ADI-192. Optical in (2 channel), AES out, clocks to MTRX (master), with SRC turned on in the ADI-192. That way I can sum sources. Prior to having SRC in the chain, I used an optical to spdif coax converter with a Neutrik 75ohm to 110ohm impedance converter to hook to an AES input but then sources need to be set to switch and not sum in DADman. I also have a Dolby DP564 for multichannel decoding which can take an optical bitstream source and reference/lock to an external wordclock (MTRX as master) and output multichannel AES which feeds into the MTRX as a source.)

[SomeOtherGuy]

Originally Posted by JFreak

Usually that is just sensible thinking.. but correct me if I'm lost but wasn't the original trouble to just get PLAYBACK from ATV

For sure, but PT everyday work setup needs to remain the same. I just want the ATV to be connected, simply for entertainment only.

[SomeOtherGuy]

Originally Posted by BScout

The MTRX never runs on any clock but its own internal. What it does do is reference external clocks. There is a difference. It buffers the incoming clock to find the sample rate and then matches it internally.

(I use an RME ADI-192. Optical in (2 channel), AES out, clocks to MTRX (master), with SRC turned on in the ADI-192. That way I can sum sources. Prior to having SRC in the chain, I used an optical to spdif coax converter with a Neutrik 75ohm to 110ohm impedance converter to hook to an AES input but then sources need to be set to switch and not sum in DADman. I also have a Dolby DP564 for multichannel decoding which can take an optical bitstream source and reference/lock to an external wordclock (MTRX as master) and output multichannel AES which feeds into the MTRX as a source.)

That's interesting, thx. I'm going to experiment with switch instead of sum with the Neutrik to see what that may do, if anything. But then I can't keep the system in switch mode permanently...