Can't connect to 96khz with Itunes

[ryan_d]

Hi all,

 

I'm looking for advice...I currently use a macbook pro connected via optical to a perpetual technologies dac which can allegedly support up to 96k. I use Itunes and have it set in Audio Midi to 2ch 24bit at 44.1k as per norm for cd's. I've recently downloaded some hi res files and want to utilise the capabilities of my dac.

 

I ten set the audio midi to the correct settings for the files, quitting itunes along the way as per instructions but it would give me a stable connection at 96k. I was originally using a monster optical cable with adapter and saw posts that this caused connection problems so I bought a Van den Hul Optocoupler mini jack to optical with no adapter and following the usual set up procedures still can't get a stable connection at 96k. It will connect at 48k though.

 

SO i'm now thinking there may be a problem with the dac or my mac.....any advice would be appreciated.

 

Ryan

 

[The Computer Audiophile]

Your Mac should allow the 24/96 setting even without a DAC connected. Can you select 24/96 in Audio Midi? Is your DAC only receiving a 48k signal or something? How do you know it's 48k? Is there a readout on the DAC?

 

This should help us get to the bottom of it. My guess is your DAC has an issue or optical limitation.

 

[ryan_d]

Thanks for the response Chris. I don't have a read out on my dac.....its a Perpetual Technologies P-3. But it does have a light if its making a connection at specific frequencies and this fluctuates between green (connected- obviously) and red. Its audible also. It makes a connection at up to 48k but not at 96k.

 

As I put in my post I initially thought that this was a problem with the cable and its adapter but I now have an optical cable without an adapter and still getting the same problem. Optical is not limited up to 96k according to dacs manual. Only at 192k is it limited.

 

Ryan

 

[ryan_d]

Sorry I forgot to answer your question Chris.....my mac can do 24/96 and changing it in audio midi is no problem.

 

Ryan

 

[flatmap]

Could you carry your DAC and cable over to a friend's house and try it on their computer? If it works instantly, then there's something funky with your Mac Book. If you have exactly the same behavior there, I'm inclined to suspect the DAC.

 

[Audio_ELF]

You question if either your Mac or DAC is faulty but re reality is it maybe neither. IIRC (and please forgive errors here it's late) there are several varieties if SPDIF and TOSLINK (optical) with some variations between how try data is transmitted. Now most DACs will suppor slight variations in the data (like AES/EBU frames being sent to SPDIF devices) however some stick strictly to the protocols.

 

It's a bit like some web pages work perfectly on Internet Explorer, but fall over on Netscape (yes old analogy) because Netscape stuck more ridgedly to the original RFC document specifications.

 

Possible solution would be an M-Audio transit or similar USB or firewire interface beween the Mac and the DAC.

 

Eloise

 

P.S.1 of course it could also be a bad connection at either end due to damaged connector, dust collection, etc.

 

P.S.2: what happened to Perpetual Technologies - I can find any reference to re company online. I assume they are another example of "good product same about the marketing, and (lack of) sales"?

 

[ryan_d]

If it was down to dust on connections then why would it only happen at 96k? Connectors have been changed as the cable is new and I have checked it for damage.

 

Thanks for the suggestions though. Will look into the interface.

 

The dac is actually very good too....its the Modwright one also.

 

 

 

[Audio_ELF]

Re dirt / dust on / in the connector(a) was just really a though. As for why would only affect 24/96k well the data is transferee at a higher rate. Same reason why some people have found the Mini-TOSLINK adaptors fine at 16/44.1 but fail at 24/96. It should work fine with either, but at higher bitrate the optical transfer need to be cleaner.

 

Eloise