Static noise from optical audio port of AppleTV 3

Thank you Golfwhenucan. I also have an old Airport Express (model no. A1264 - can only be read with lots of light and a magnifying glass!), which I use to get my laser printer onto my home network. I also tested using this Airport Express (optically connected to the DAC) instead of the AppleTV 3. Result: no noise! So I can confirm your finding.

Now you say that the new Airport Express suffers from the same problem as the AppleTV 3? I was about to buy one of those new Airport Express thingies. I guess I could always use the new one for the printer and just use the old one for music streaming. It is kind of silly though, since I already have the AppleTV close by my stereo and TV - and this is SUPPOSED to be able to handle this job! Unfortunately, my AppleTV is just a month or two over two years old - and where I live the warranty is two years. The thing is, I've not tried to stream music to it before, so I didn't notice the problem before it was too late, as I didn't own a DAC.

By the way, I believe my old Airport Express is second generation (model no. A1264), even though it's the kind that plugs directly into a wall socket. So I guess the current Airport Express (similar to AppleTV in shape) is third generation.

Finally, I would like to ask you an additional question about your Marantz HD-DAC1:

Mine is in for repair right now, because I experienced noise when using the front iPod/iPhone usb port. The noise could only be heard when using headphones or the variable out on the back panel. In other words whenever the volume knob was engaged simultaneously with the iPod port being used. I don't have an iPod, but I was using both an iPhone 5c and the latest iPad Retina. The noise level was constant irrespective of the setting of the volume knob (except the noise would almost disappear at close to maximum volume), increased when increasing the Amp Gain setting, and was sensitive to display changes on the iPhone/iPad (more noise when using the touch interface). So here is my question: Have you tried to connect an i-device to your HD-DAC1 via the front iPad port? - and have you experienced anything like what I've described?

Thank you for your reply Golfwhenucan! Yes, after recording the noise, the store where I bought the HD-DAC1 agreed there was something wrong with the unit. Your experience confirms this. I'd only had it for a week or two... Looking forward to getting it back - fixed. It sounds really great when there's no noise! I have an old pair of Sennheiser HD580 Precision headphones that are too power hungry to sound good connected directly to an iPhone, but sound GREAT connected to the Marantz HD-DAC1.

I've now received a replacement Marantz HD-DAC1 - and the noise problem when using the iPod/iPhone port is history. Apparently, Marantz were aware of the iPod direct problem and had issued service directions to their repair channels. Some resistors needed to be replaced, but due to long delivery of the components, the dealer where I'd bought my Marantz HD-DAC1 chose to replace my unit, with a newer one where the issue had been dealt with in production.

When using the Apple TV, I still have the static noise issue I originally posted here about. No better, no worse (just as expected).

While I've been waiting for the return of my DAC, I bought a latest generation Airport Express (model no. A1392 - the one that looks like a white Apple TV) and as I've written in an earlier post, I already owned a second generation Airport Express (model no. A1264). So with my brand-new Marantz HD-DAC1, I've done some testing and have found the following:

1. Optical out from Apple TV 3, model no. A1427, gives off a disturbing static noise (sounds like a scratched vinyl record) whenever it is turned on, regardless of whether there is a sound signal or not ( = the issue I originally posted here about). Another thing is that Apple TV will always send sound on optical out at a 48 kHz sample rate. In other words it will perform a resampling (with loss of sound quality) in the most hi-fi applications. Hi-fi? Well, that is questionable! I deem the Apple TV useless in hi-fi applications. Not only is the static noise way too prominent and disturbing, but also the airiness, detailing, presence - and hence musicality of the music - suffer!
2. Optical out from Airport Express, model no. A1392, also has some static noise, but it does not sing its ugly tune as frequently as on my Apple TV. When using Airplay from my iPhone, the signal is transferred at the native sampling rate of 44.1 kHz, and the quality of sound is definitely better than through the Apple TV. I suspect this is due to the fact that the signal is not resampled, like in the Apple TV.
3. Optical out from Airport Express, model no. A1264, has no static noise and sounds better than the newer Airport Express, model no. A1392. Here we're getting closer to true hi-fi, but even this - my best Airplay option - does not sound as good as when I connect my iPhone directly to the Marantz HD-DAC1 via its charging cable! Now we're talking!

In conclusion, I am now a very happy owner of a Marantz HD-DAC1, but still not happy with my Apple TV 3. I'll be using Airplay over my model no. A1264 Airport Express for background music to speakers, but for serious listening I'll be using a cable from my music source to the DAC - and 9 out of 10 times I'll be using a good pair headphones for this!