Node N130 - Digital, Analog, and the "digital pass-through" setting.

Sander

• January 06, 2025 18:46

I have my Node N130 connected in duplicate to a pre-amp which also has a built-in DAC.

• Analog output RCA to analog input on the amp, to use the N130 internal DAC. I do this so I can listen to the TV connected to the Node via HDMI.
• Digital output Toslink to digital input on the amp, to bypass the N130 internal DAC and use the amp's DAC instead.This is for my music streaming services Spotify, Tidal and Qobuz.

By switching the input selector on my amp, I choose which option I want to listen to.

I saw in the BlueOS software that there is also an option for "Digital Pass-through", which says that the Node will only output the stream and bypass the internal DAC. When I turn this option on, I expect the analog output from the Node to go quiet and that I can only hear music via the digital connection. But the analog still works, and the digital also works, whether I turn the Digital Pass-through on or off - it doesn't matter. Shouldn't the digital output (Toslink) bypass the internal DAC anyway?

So I wonder if that option even does anything? When it comes to sound quality, I hear no difference at all when I switch Digital Pass-through on or off. I don't think I can even hear a difference between the analog or the digital connection between the Node and the amp.

I'd love to hear your thoughts on this.

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• Official comment

  

  Tony W.

  Product Support Manager

  • January 06, 2025 19:02

  Hi Sander

  Both the Analogue and Digital outputs are 'hot' and active.

  Digital Pass-Through (formerly External MQA DAC) is to be used if your external DAC is capable of MQA playback. See here for more details; https://support.bluos.net/hc/en-us/articles/360045466694
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  Sander

  • January 06, 2025 19:41

  Thanks Tony!

  One thing does confuse me, why not name it "MQA pass-through" if that is the only function it does?

   

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  Frank Sullivan

  • November 01, 2025 23:38

  The answer to the question asked by Tony is still unclear. It would appear that digital passthrough is irrelevant and does nothing if your external dac does not process mqa. So if none of my music is mqa encoded then digital passthrough does nothing on or off. The answer is important to me because I want to use variable volume control on the node and an external dac and the only way to use variable volume control is to turn digital passthrough off but I want to be sure that the node is passing through unprocessed digital signal. Another post suggests that with digital passthrough off the maximum streaming rate it will pass through is 24/98 even if the original is 24/192 but after I tested that it is not the case so what does digital passthrough actually do to a input signal that is not mqa encoded

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  Pinot Gris

  • November 06, 2025 10:32

  The use of tone controls, replay gain or variable volume level will each affect the digital audio stream. So you can have either an unprocessed digital audio stream or variable volume control, but not both.

  Transmission of a digital audio stream over fibre optic Toslink could get limited to 96kHz, if one or more components of the transmitter - cable - receiver chain do not support higher rates. The original specification for Toslink by Toshiba was limited to 96kHz, hardware based on this limit is quite common.

  Transmission of MQA decoded on the BluOS device appears limited to 88.2kHz. This is where the passthrough setting comes into play, allowing a full decode to 352.8kHz by the external DAC.

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