DSP Engine use with external DAC

Hi everyone.

I am a new Roon user and after 2 days of the trial use decided to become a life member. I am so impressed with this software and the flexibility. I am still an avid Vinyl user but Roon has given me a good reason and place to start tp seriously focus on streaming and digital content.

I am trying to evaluate use of the DSP engine in my setup. I am using in my system a Mac mini connected via USB to a SimAudio Moon 300D DAC which is connected to my NAD Master series pre-amp and power amps. My speakers are Wilson Audio Sasha II. I have a range of digital files from lossless to lossy to compressed MP3. I am slowly working my way back to ripping my CD collection as lossless.

My DAC up samples @24/192K and provide the Analog input to the NAD which internally converts @ 24/192K.

Given my hardware is up-sampling I am wondering if the DSP engine will improve the sound? I have read it is best to do the up-samping as near the source as possible.

With some random listening I really can’t tell the difference with the DSP engine in the chain. Perhaps one or two tracks sound a little deeper and better dynamic range, but hard to tell.

I would appreciate any thoughts on this. My instinct is to keep the distance from file to my speakers as short as possible and rely on the external DAC and keep the DSP Engine turned off.



You ought to specify which NAD Masters components you are using. If either preamp or amp is inherently digital, then you already are adding undue “distance” to the signal chain by using a separate DAC, thereby imposing redundant D/A/D/A conversions.



Thanks for your reply. You are correct, I have looked into my NAD amps (M17, M27). They have the same Burr Brown DAC’s as in the SimAudio. I have decided to remove the DAC from my system and connect via HMDI.

I appreciate the feedback.

Depending on how receptive the DAC in your NAD hardware is to upsampling, I would take a look at HQPlayer for upsampling instead.

The NAD M17 pre/pro should allow a pure analog signal path – if you wish to pursue that route. But any surround processing or other processing of an analog input will invoke A/D conversion.