Hi all, as discussed elsewhere my naim system is largely driven by a DIY HifiBerryDigi+ Rpi roon endpoint (into a Dac V1). It works great!
I’m curious as to any thoughts and experience people have in this space however as there’s always room for improvement
One thing I’m especially curious about is USB vs. coax results with the Dac V1 - right now I am using coax, (the Digi+ Pro). But in theory I understand the reduced jitter benefits of async USB, which the Dac V1 supports - would I be likely to see improvements here if I went for say an Allo USBridge Signature?
Any experiences around upgrading to an Allo Signature (not USB), and using the shanti or otherwise power supplies?
Appreciate any thoughts and conversation around the topic!
USB tends to be better than SPDIF on lower end components because of reduced reliance on the clock. Hence, even if a computer has coaxial out, you are likely to have better results with USB.
However, after a certain point the additional noise from the lower end transports that the USB cable introduces to the DAC is likely to become a noticeable issue once the DAC and rest of the system reach a certain point of fidelity where they are sensitive to such things.
So USB really is great for what it does. Ultimately, though, higher end DACs are moving towards AES/EBU and I2S rather than coax, optical, or USB.
Back to the V1, connecting to a homebrew transport, USB is almost certainly better. Connecting to a high end transport like a DCS Network Bridge, Coax is almost certainly a better option.
I haven’t compared the HifiBerry and Allo, but the latter is widely considered an upgrade. Lots of discussion on the web on the HifiBerry vs Allo DigiOne Non-Signature. And considering the improvement the Signature brought, one can assume that the gap between HifiBerry and Allo got larger. Further improvement apparently when using the DigiOne Sig with Allo USBrigde Signature, rather than a conventional Pi. @suzywong might be prepared to share their experience. Of course, further improvements when using better power supply – Shanti seems like the obvious, cost-effective choice.
Interesting topic, I’m in the process of evaluating a Pi based streamer/Roon Endpoint for a friend who wants to add something simple and cost effective to their current system and remove the need to rely on a laptop to drive it all.
Is there a leaning towards the Allo options as a preference here?
Adding to this thought, he already has a USB DAC (iFi iDSD Nano) that will be repurposed (currently connected to the MacBook).
Doing a bit of digging it seems the Pi 4 is recommended due to shared bus and noise issues with USB on earlier Pi’s.
Setup would be along the lines of:
Pi -> USB cable -> iFi USB DAC -> RCA L/R cable -> Amp input
Pi would be mains powered and fed over Ethernet for networking.
Not sure I believe that at all from my experience really depends on the DACs usb implementation. My RME is pretty much transparent across sources and it’s a very very good DAC.
@smilen - I use the DAC-V1 USB input. It has been such a long time since I tried the SPDIF. It would be hard in any case to compare the two as the signal path chain in my setup would be different. The DAC is in fixed output mode.
What I found earlier on was that even with the galvanic isolation, it was sensitive to the USB signal (e.g. changing USB cables, PCs, laptops etc altered the SQ] likely due to some noise infiltration. The DAC-V1 output was like a clear lens looking at a ‘dirty’ upstream!
This of course gave the opportunity to research how the fed signal could be ‘cleaned up’. The audiophilestyle website was very helpful in this regard even though there are a few rabbit holes there. In case you have not done so - if you do a search there you will find threads on the Raspberry Pi.
In summary every thing upstream that I have done now improves the perceived ‘background silence, sound stage focus, low level sounds and trailing decays’ i.e. enhanced the music soundscape perception. Keep in mind though that each change also can have its own sound signature (e.g. what power supply you use) so it is all personal preferance and there are some trade-offs.
Below is a newer picture similar to what I posted there some time back, some of the annotation would be for that site. Basically this is a control/endpoint 2-PC setup running JRiver on the two machines. The endpoint is an Intel NUC with the Audiolinux (proprietary) OS loaded/run from RAM. The control PC is an older one with Win 7, soon to be upgraded.
There are some brief subjective notes in the picture that I made to myself. I hope all this is of some help! The idea is to reduce the CPU load and isolate from the LAN using a bridge between the control and renderer, server.
I did ask J River at their forum for an expert view of why the SQ is better with this setup than that of either PC as a single- I only got a ‘frown and headshake’ -and the exclamation- audiophiles!
PS - I did try ROON a few years back, loved the UI but found the SQ to be a tad less than J River’s- hope that one day they can rectify that (from what I read, they haven’t)!
I would focus on a quality 75ohm impedance SPDIF interface ensuring there is a galvanic isolator (typically a transformer), prefereably at the send end. SPDIF is unbalanced and AES/EBU is the balanced equivalent, though I wouldn’t focus on the latter unless you have longer distances to run your digital lead over or you need specifics in the AES/EBU protocol extensions over SPDIF … rather unlikely.
SPDIF transport flow is simpler than USB so less processing as it is a simplex flow. USB has the propensity for noise on the power lines in the USB lead.
Both USB and SPDIF clocking are decoupled from the DAC clock on almost all DACs… unless you have a very early model from 90s. However with SPDIF you also have the advantage of usually using a sperate serial line transport clock, which you can be very stable producing less sidebands that can couple into the receiver.
USB on the Pi on many of the models is also shared on the i/o bus so can be rather noisy and even contested.
However SPDIF framing protocol is ultimately limited in terms of bandwidth, and so if you want to work above 192/24/2 then you will likely need USB.
