R-Pi 4 with stand-alone Dac

[Bourneendboy]

I keep being tempted by a standalone Dac, has anyone tried a R-Pi 4 straight into a Dac via USB without a Digi hat? Wondering if the fact that the USB/Lan issue has been revised that the digi hat is no longer required.

[Lawrence001]

I don't know anything about these issues but my RPi 3 b+ works fine into a USB dac without a hat, as long as the dac is not using the usb for power.

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[Bourneendboy]

I don't know anything about these issues but my RPi 3 b+ works fine into a USB dac without a hat, as long as the dac is not using the usb for power.

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Cheers Lawrence:)

I am aware it is possible and did do this for a short time in between systems with a Dragonfly Red. What I'm interested in is any sq comprises from not using a hat.
Are you suggesting there aren't any if not powering the Dac?

The Dac in mind is an NJC Audio Reference Dac to go with their headphone amp I currently use. This is mains powered.

[Bencat]

I use an RPi 3 in to a usb to SPDIF convertor via the USB out and this sounds fine . However if you want to use the RPi direct in to a USB DAC as you indicate then I would recommend that ypu look to get the new RPi4 which is out now.

This unit is much quicker and has a great deal more RAM the previous RPi boards and more important it has full USB 3.0 outputs that will match and feed in to a stand alone DAC much easier . I feel (as I have not yet tried this ) that this will also have a less compromised sound quality output as the USB has its own power feed from the board .

[Lawrence001]

I'm a bit out of my depth here technically add I'm not familiar with the strengths and weaknesses of the the Rpi other than power supplies. But I'll stick my neck out and say the following:

I should have clarified my statement about USB DACs with regards to compatibility. I've tried about 6 DACs and external SPDIF convertors, and one of them wasn't compatible. (It was recognised but no sound came out.) This may sometimes be a function of the software you are using eg. I use Squeeelite. Most are plug and play with Linux but in my case I looked it up and apparently I need to add a command line in the "Kernel" or something which I will get round to one day if I can work it out. (So it's a fundamental Linux set up issue, not the music software)

Regarding SQ I'm not sure that a Hat spdif converter is necessarily any better than an external one (either built in to the DAC or a separate box). If it's drawing the power from the Pi then it will have issues around that, but on the other hand it may use the I2S link which apparently is better, though I've heard some don't find that in practice. Probably, a better stand alone mains powered spdif converter will outperform a built in piggy back one regardless of connection YMMV.

Going direct to a USB dac, again assuming mains powered, much is dependent on the built in USB convertor, older ones (say 5+ years) tend to be outperformed by relatively cheap separate ones these days as the technology has moved on (moreso than dac chips where opinion is still rather polarised, I tend to veer towards the older less clinical sound but only in the best implementations eg Trichord, Pink Triangle, but newer NOS DACs can come close eg Chevron, Metrum).

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[Bourneendboy]

Thanks for your comments fellas.

I'm only interested in the NJC Dac if I'm going to do this, but unfortunately a trial/demo is not possible - I have asked them.

More pondering required:)

[Lawrence001]

I would check the spec of the latest version as I found this in an online review, but it was from 2016 and might be an old spec. It implies the USB convertor is one of the old chips I referred to that are outclassed these days. Hopefully the MK2 version is higher on USB.

"Full spec is on NJC's website - but this is a back to basics simple design so limited inputs (Coax (24/192), Optical (24/96), USB (16/48) and one analogue).* The USB is not asynchronous (NJC audio's view is that whilst asynchronous is a cost effective way of reducing jitter its own jitter attenuation methods are equally effective and have other advantages.) and the USB won't support High Def.*"

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[Bourneendboy]

I would check the spec of the latest version as I found this in an online review, but it was from 2016 and might be an old spec. It implies the USB convertor is one of the old chips I referred to that are outclassed these days. Hopefully the MK2 version is higher on USB.

"Full spec is on NJC's website - but this is a back to basics simple design so limited inputs (Coax (24/192), Optical (24/96), USB (16/48) and one analogue).* The USB is not asynchronous (NJC audio's view is that whilst asynchronous is a cost effective way of reducing jitter its own jitter attenuation methods are equally effective and have other advantages.) and the USB won't support High Def.*"

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Thanks for pointing that out, I hadn't spotted it.

I know I'm best to stick with what I have, save the money and not have the hassle of selling my existing stuff, its my obsession kicking in.......

[struth]

Inclined to think although changes may seem good initially they usually level out as your hearing adapts.... Get something you like and stay with it is my advice, or you'll never be happy..... unless you enjoy it of course:eek:

[Bourneendboy]

Inclined to think although changes may seem good initially they usually level out as your hearing adapts.... Get something you like and stay with it is my advice, or you'll never be happy..... unless you enjoy it of course:eek:

I know you are right Grant, wise words!

[Bencat]

Well I have now managed to create a Pi that works direct out from the USB (in the past never managed using Picoreplayer probably my lack of technical skill) . Have then tried and completed using Max2play both a Pi 3 + and an RPi 4 2TB .

In both cases this has been just in to a simple USB to SPDIF converter but I did borrow an MDAC over the weekend and it worked just as easily in to that . Both work well and sound pretty much the same so much so that I feel it would be very difficult to identify one over the other. However I will stick my neck out and say that the RPi 4 seems to be more stable and has a lower noise floor than the RPi 3 which given that the RPi 4 has a full USB 3.0 set up is to be expected.

In my view the sound quality is excellent and given the really cheap nature of this set up it will take quite a large investment in over specified and perhaps wasted hardware to get the same result . All the RPi is doing is transferring the stream to the DAC of your choice and this will have the biggest influence on the final sound quality .

This is now not only possible but if you have a USB DAC would be my recommended scheme for adding streaming music both live and from your Library to your system .