asynchronous USB Dac to av receiver

[ethan]

...as a newbie I don't really understand the ins and outs of connecting these things but I quite often hear or read about people asking whether you can run a asynchronous usb dac such as the teac UD-H01 to an av receiver. One I don't know the reasoning for this and two if it's even possible or indeed if there are any benefits to be gained. Thank you.

 

[lucid]

The simple answer is Yes. All an asynchronous DAC is doing is providing a more accurate transfer of data via the PC's USB connector. How it does this is by the DAC having its own data clock which is said to be more accurate than the one in a PC.

There are a few caveats though...

Firstly, the idea of running an asynchronous DAC is is really a Hi-Fi purist thing. The typical amp would be an all-analogue affair. By contrast, many of the AV receivers on the market including those that feature a "Pure Audio" mode still have digital signal processing running in the background. Tip: If you can use "Pure Audio" mode with an audio signal via HDMI, or optical, or coax then it's not a true all-analogue signal path.

On the PC side, the USB port needs to support asynchronous transfer. Some information suggests that this is only possible with USB 3.0 (A.K.A. SuperSpeed USB).

On the receiver side, you need to be sure that the receiver doesn't digitise the incoming analogue signal from the DAC. It would be a waste to have spent time and money ensuring the cleanest and most accurate data transfer and decoding, only for the AV receiver then to undo all the benefits by converting the signal back in to digital for it's own internal processing. Make sure your receiver has an all-analogue throughput mode so it doesn't trash the music.

Third, make sure your speakers are up to the job. Sub/sat speakers are out. If you want to preserve the integrity of the music then your front speakers need to be full range Hi-Fi speakers. You'll be running the receiver in pure stereo (digital bypass) mode, which also means the sub won't be active either. If the amp is driving the sub then it means it has digitised the signal, and so potentially chucked away the benefits of your super-duper DAC.

Finally, it's the files themselves. You can't polish a turd. If your file rips are lossy then the data is already gone. Spending money on a clever DAC isn't going to get back what's been thrown away... no matter what the advertising material says.


As long as the files, the PC, the AV receiver and the speakers are all up to the job then you may well hear some benefits. If there's one weak link in the chain though then you might be chucking all the benefits down the drain.

 

[ethan]

I might have a go at this if it is possible with my setup? Pioneer vsx 527 until I can afford to upgrade to an Azur. If not I'll just buy it for stereo.

On the receiver side, you need to be sure that the receiver doesn't digitise the incoming analogue signal from the DAC.

Would that mean direct stereo mode or stereo alc (headphone use)?....and connection to the receiver via rca? Sorry for what may appear as a stupid question.

 

[lucid]

Well, your connection on the amp side will be via RCA no matter what. That's the whole point of a DAC. It's a Digital to ANALOGUE Converter , so the output is analogue and that means RCA connectors*

As for the Pioneer amp. It has a Pure Direct mode. But unless you know the way it's wired internally it's impossible to say for 100% certainty that the analogue inputs are wired directly to the volume control and then to the power amp, which is what a true "Direct" mode does.


I have to be honest here.... The Pioneer is a sub-£200 AV Receiver. Proposing to spend almost as much on a DAC doesn't strike me as a worthwhile upgrade. I would have thought that the amp is too much of a bottleneck to hearing the potential benefits of the DAC. I'd be tempted to hook up the amp's network connector and use the streaming features to bypass the PC audio output completely.

Maybe come back to the ideal of a DAC when you've upgraded to the Cambridge Azur. If it's the 540R or 640R then I believe they both have direct 6.1 inputs which totally bypass all the digital processing.



*Unless you're a user of older Naim gear in which case it means DIN, or if you're a user of some semi pro/high-end gear in which case it could mean XLRs.

 

[ethan]

Thanks for the input. At least you don't think it would be a waste with the Azur Tbh it depends on what kind of a deal I might be able to get in the next month or two, and even then, "price willing" it might be an Arcam.