Make signal path lossless for devices running BluOS

[RBO (Dislikes people who wear sunglasses indoors.)]

Hi team,

This was reported to yourselves and Bluesound back in 2021 - analog amplifier step makes signal path enhanced.

Their reply in 2021:

Whilst I know it has no effect on sound quality, I would rather have it display lossless and not enhanced. Me likes the purple light

Have seen this analog amplifier step appear for other manufacturers and it does not result in an enhanced signal path. Cambridge Audio for example.

[Martin_Webster]

I think Bluesound applies DSP within the amp, which is why it shows as enhanced. That’s certainly the situation with the Pulse Flex. This then is consistent with Roon DSP.

[RBO (Dislikes people who wear sunglasses indoors.)]

Thanks for chiming in Martin.

It’s just strange that Bluesound are blaming Roon and Roon are saying this is not something they requested.

[CrystalGipsy (Resisting the flow!)]

The Hifi amps don’t do anything unless you turn on DSP they should report as it is, my node 2i did when I had one however it does nothing to change this in Roon for the Hifi amps. Same issue for my NAD T778.

[RBO (Dislikes people who wear sunglasses indoors.)]

For clarity - I have no DSP applied in the BluOS app.

[RBO (Dislikes people who wear sunglasses indoors.)]

@support Anything you can share on this?

[Martin_Webster]

Good point. AFAIK, their speakers use DSP to enhance base etc., and the Flex … well, it’s a single speaker.

[Gavin_Ambler]

Can I add another one keen for clarity thanks

[RBO (Dislikes people who wear sunglasses indoors.)]

Stole this from @Wes, showing the signal path from a Hifi Rose and it’s digital amplification appearing as it should be - “Digital amplifier”

Note this does not make the signal path enhanced.

Since the M10 is also a digital amplifier, its signal path should be the same as Hifi Rose’s.

@wes, is this something you can help us with? Please

[Martin_Webster]

@RBO

Note this does not make the signal path enhanced.

Yes is does! It’s identical to the M10, except for text under “Amplifier”.

[RBO (Dislikes people who wear sunglasses indoors.)]

Look closer Martin. The light next to the amplifier step is purple.

[Martin_Webster]

Yes, but the signal path in both examples is enhanced. Or, are you suggesting an amplifier stage should always display bit perfect?

[RBO (Dislikes people who wear sunglasses indoors.)]

They are indeed enhanced in both but for different reasons.

NAD M10 - amplifier step turns signal path enhanced
Hifi Rose - it is the parametric eq step which turns the signal path enhanced.

Hopes this makes more sense?

As for the lossless part, I think it should. It does so for other devices.

In addition to this, the M10 is a digital amplifier and not analog.

[Martin_Webster]

Yes, I understand. Since some Bluesound devices do use DSP, I’m guessing they are all treated the same. I recall a comment by a Roon staffer on a similar discussion where this approach is taken for another product range … although I can’t remember the brand.

[Gavin_Ambler]

I think I’m more baffled than before. No dsp set up from my Roon settings. So suggestion is that the nad / BluOS amp is performing some dsp, that cannot be unselected?

[RBO (Dislikes people who wear sunglasses indoors.)]

Only @support can shed light on this.

[Gavin_Ambler]

Roger that….

[Gavin_Ambler]

So we are reduced to obi wan only help etc plaintive cries. And we sadly ain’t Carrie fisher.

[RBO (Dislikes people who wear sunglasses indoors.)]

My original post about this was more than one year ago and ended up being closed due to inactivity.

So I figured I’ll try my luck again.

It’s been 12 days and no input from Roon.

[Wes]

Hi @RBO,

Long time no see. I’ve been out of the community and doing our Roon Ready testing but our own @noris brought this to my attention.

Here’s what the M10 is reporting to us via your logging:

--[ SignalPath ]---------------------------------------------
SignalPath Quality = Enhanced
Elements:
    Source Format=Flac 44100/16/2  Quality=Lossless
    Raat Device=NAD M10
    Amplifier Method=analog Quality=Enhanced
    Output OutputType=Local_Speakers Quality=Lossless SubType= Model=
------------------------------------------------------------

Just as pictured in your screenshot, the path is outlined in the logging. Everything below the Roon Advanced Audio Transport portion of the signal path is coming from the device itself.

Here’s what I am seeing for the Hifi Rose issue you referenced and it’s a similar story. However, their issue is that it’s relaying signal path elements when no EQ elements are active :

--[ SignalPath ]---------------------------------------------
SignalPath Quality = Enhanced
Elements:
    Source Format=Flac 44100/16/2  Quality=Lossless
    Raat Device=Rose RS520
    ParametricEQ
    Amplifier Method=digital Quality=Lossless
    Output OutputType=Local_Speakers Quality=Lossless SubType= Model=
------------------------------------------------------------

I would agree with the Blue support’s assessment that sound isn’t being modified but regardless, I’ve relayed this over to our partner’s team to see if there’s anything the folks at Bluesound can do to remedy this.

Kindest regards,
Wes