Audirvana settings w Directstream


#1

Hi all. I’m reviewing all the settings on my system and am drawing a blank about my settings. My equipment consists of a mac mini running Audirvana 1.5.1.0. > PSA Directstream > Mcintosh pre amp. I have the volume on A+ set to -12db. Is that the correct setting? Also the PS Audio users guide says to set my computer output to 192 / 24. I do that in the Audio Midi set up, but as soon as I play something it changes to match the music file. I appreciate any advise you can give.


#2

In audio, there are many opinions - I shall offer mine here and you can do with it what you wish. I am a Windoze user rather than Mac, so my offerings will be generic with little Mac experience and no specific experience with Mac audio.

In general, it is thought better to pass the audio to the DAC with no processing, including volume. The DirectStream does an excellent job of handling the data and does its volume processing in the Sigma Delta modulator where there is littlr if any loss in resolution until extremely low volume levels are required. Even then, the loss is considerably less than PCM volume calculations. On the other hand, a 12dB reduction is just a two bit shift and little if anything will be lost even on 24 bit files. If this gives a better level match with your preamp/amp/speakers then it might be the preferred option.

As to the sample rate and bit depth, again the DirectStream does an excellent job of handling the data and sample rate so it is probably better to send the music to it in its original sample rate. At best, sample rate converters do minimal damage to the audio being processed. Some computer based SRC may be as good as those in the DirectStream, but I believe that many are not. Those that are in the DirectStream are optimized for the hardware, so almost certainly the best suited for the job.

J.P.


#3

Thanks JP I was concerned that full volume (0db) from Audirvana + might be over driving the signal. I’m in over my head understanding the technology. Theoretically, 0db is just the full signal and no need to worry about digital clipping, right?


#4

I agree with JP. If you have any DSD files you also need to forgo any digital signal processing, including volume adjustments, for those files or you’ll just get noise. One of the things Audirvana and similar Mac programs do is get around the fixed sample rate and bit depth settings in Audio Midi Setup. Sounds like Audirvana is doing what it is supposed to do. “Digital clipping” only occurs with PCM files when an attempt is made to record a signal above 0dB below full scale so no need to worry about digital clipping in playback. I always run my DS (and PWD before it) at 100 (with no digital signal processing, including sample rate conversions) and use the preamp to control volume, although, as JP said, the digital volume control in the DS is very good.


#5

Thanks guys. Putting the volume up on Audirvana solved my DSD problem too. beer_gif