Can I get 192khz/24bit optical output on my mac?

[malota]

Hi I have an iMac and have found that I can only get upto 96/24 on the optical out and I'm trying to see what options are available for me to get 192/24 on the optical out to my Yamaha receiver that has a built in 192/24 DAC. NB:I do not want to use an external USB DAC as I need to keep the equipment to a minimum and I don't see any reason in doubling up if I already have a DAC in my AMP.

 

So the only options I can think of are.

 

1. custom audio drivers - From my reading the standard drivers in OSX do not support 192/24 out even though the chipset can

 

2. upgrade to a MacPro? But I don't know if this supports the higher resolution out the optical out?? Anyone know?

 

Any ideas or thoughts on the above would be much appreciated.

 

 

[wgscott]

I think optical can only go up to 96kHz, and in my experience even that might be pushing the envelope.

 

Hiface/coax might be an option if you really need that output. (At some point sampling frequency becomes overkill.)

 

[Miska]

With bootcamp the Windows driver supports 192/24 on many Macs with normal HD-Audio chipset.

 

Also most other equivalent normal PC motherboards with optical output seem to work. I've tested to Yamaha HT-amp. The only limitation seems to be that cross-overs and all other DSP processing is disabled and the amp goes into "through"-mode with 176.4/192, since all the internal DSP processing is done in 96 kHz... So for higher rates it goes into DSP-bypass mode.

 

Sony PlayStation3 is also capable of outputting up to 176.4/192 through optical output. Maximum rate for proper optical S/PDIF is at least 15.5 Mbps.

 

96 kHz limitation seems to be common on OS X, for hardware which supports 192 kHz on other platforms like Windows and Linux.

 

[wgscott]

The newest Powerbooks don't have the limitation. The problem is that optical cables probably aren't able to cope with that output.

 

[Miska]

The problem is that optical cables probably aren't able to cope with that output.

 

I haven't yet seen any problems putting it through even cheap optical cables.

 

IMO, coaxial S/PDIF is more tricky due to required isolation transformers... Of course there are also cheap electronics omitting the transformer altogether, but that's especially bad for other reasons.

 

[wgscott]

Oh, I thought it was a cable limitation.

 

Considering I can't get 96kHz through an $80 glass Silflex cable from our Macbook (the $8 plastic one works ok), I thought I was pushing the limit.

 

In that case, the new Powerbooks should be able to do it.

 

[Miska]

Considering I can't get 96kHz through an $80 glass Silflex cable from our Macbook (the $8 plastic one works ok), I thought I was pushing the limit.

 

I don't even have any expensive optical cables. All are some noname roughly 5€/m ones. Longest one is 5 meter very flexible plastic (?) coming from PS3 and works fine to 176.4/192 to a Yamaha HT-amp...

 

As all fibers, terminations are most sensitive parts. Best of the cheap cables have metallic holder (inside the Toslink connector square) for the fiber end.

 

Oh, and for Macs, don't use those mini-to-Toslink adapters, but get proper cables with optical mini plug connector on one end and Toslink on other end. Adapters cause losses and each connection point add around 6 dB attenuation to the optical connection.

 

[wgscott]

Yeah, I am using toslink/mini toslink. Here is a quick summary of my observations:

 

1. $0.31 toslink/mini cable worked fine for 44.1kHZ and 48kHz, but was incapable of 96 kHz transmission from my mini to Nova.

 

2. $8 toslink/mini cable also works reasonably well (but not flawlessly) with 96kHz transmissions from both my mini and Macbook.

 

3. $70 glass silflex cable works intermittently with 96 kHz from my mini to Nova and not at all from my Macbook to Nova. Oddly, the musical quality at 44.1kHz and 48kHz is slightly improved.

 

4. My DAC only goes up to 96kHz, so I have never tried to get to 176 or 192.

 

I'm not at all convinced I can hear a difference between 48kHz sampled music and anything sampled at a higher frequency, but 24 bit does seem better than 16 bit in some cases where I have compared the two.

 

I have to use a mini adapter on my laptop to Zeppelin, because both ends require the mini plug. I already have broken two in six months of occasional use.

 

[AudioBear]

I've always been able to get 96kHz through optical cables, including the glass Silflex cable, Mac Mini to DAC.

 

It is not the cable. The optical cable can carry loads more data than we are asking it to unless it is broken! It is the optical senders and receivers which may not and the differences between them on various devices may well explain the differences between the results posted here.

 

You used to be able to get 192Khz optical sender/receivers from Toshiba, but not now. They now max out at 96Khz, there are indeed cheaper ones which may not even achieve this.

 

Given a 96Khz sender or worse and a 192Khz receiver on your DAC, (maybe they have one of the old ones,) you are still only going to get 96Khz max, perhaps less. Then there is of course the quality of the sender/receivers themselves and their implementation...

 

 

[Miska]

You used to be able to get 192Khz optical sender/receivers from Toshiba, but not now. They now max out at 96Khz, there are indeed cheaper ones which may not even achieve this.

 

Other manufacturers have better parts. I have sacks of senders and receivers capable of 15.5 Mbps.

 

[nigel]

wgscott wrote:

I have to use a mini adapter on my laptop to Zeppelin, because both ends require the mini plug. I already have broken two in six months of occasional use.

 

Monoprice has mini-to-mini optical cables:

 

http://www.monoprice.com/products/subdepartment.asp?c_id=102&cp_id=10229&cs_id=1022903

 

(If you're not familiar with Monoprice, they sell very well built cables for extremely reasonable prices. They are recommended on many audio and video forums.)

 

[Miska]

Maybe a bit OT, but just wanted to make a note regarding prices of equipment. In second HTPC I have an ASUS M3N78-EM[1] motherboard, quite inexpensive part. It has on-board optical S/PDIF output working just perfectly up to 192/24...

 

 

[1] http://www.asus.com/product.aspx?P_ID=amYCbidk7vhOQLWp

 

[John]

"1. $0.31 toslink/mini cable worked fine for 44.1kHZ and 48kHz, but was incapable of 96 kHz transmission from my mini to Nova."

 

Hmmm. Does the same cable work with 96kh to the Zeppelin?

 

[wgscott]

I haven't tried.

 

[I. G.]

"It is not the cable."

 

Yes, it can be the cable. Cheap arse plastic optical cables can have just 5MHz bandwidth that's barely enough for 24/96.