Options to improve digital sound


Hi,

I am looking for some, hopefully, simple advice.  My current digital system is an M4 MacMini feeding a Holo May DAC into a PrimaLuna 400 preamp and amp.  My speakers are Devore Gibbon X.  I primarily listen to downloaded and ripped files with Roon and Audirvana.  I also use Qobuz, but not as often.

The sound quality is good, but I feel like it could be improved.  The options I'm considering are a Small Green Computer SonicTransporter i7 to replace the Mini, or a SGC UltraRendu to put between the Mini and the Holo May.

Which option would be better?  Is there a better option?  I'd like to keep the cost under around $2500.

Thanks

walt8489

The CPU utilization of Roon is quite variable, and relative.  The biggest challenges for Roon CPU are use of DSP and format conversion such as DSD to PCM or vice versa. 

It's also relative to the CPU that you have.  Very low power CPUs as used in micro PC's may be more stressed more easily.  Also, because DSP happens on the server, if you have multiple music streams going on at once this can also increase CPU usage. 

Having said all of that, the CPU usage I observe is generally very low.   Not sure what this has to do with anything though, so long as the stream doesn't break up this should not affect playback quality as the Roon endpoints keep a significant buffer. 

 

So, Roon not cpu intensive. Many monitor their cpu utilization in real time and report relatively high utilization with Roon vs other music players. Also I directly monitor cpu usage via Euphony OS, I can do this by direct connection to streamer or via tablet. I'm monitoring both temps and utilization in real time.

As for digital packets not impacting analog signal, laughable. Streamers don't affect latency, nonsense.@sns 

Taking what I said out of context. Never said Roon was not, said streaming is not. What ever Roon is doing is in addition to the music stream. Chances are they are separate processes/streams. 

Also never said, packets will not affect the analog signal. What I said was Analog and digital are very different, same rules do not apply. If you streamer is in fact introducing network latency, then your streamer needs to be replaced, or upgraded. A streamer should never have network latency.  If I can stream 4k video with Dobly Atmos, you should be able to stream Hi-rez audio. Something else is going on if you are having latency issues. 

@shalommorgan Whether CPU processing noise is relevant, I don’t know. I feel electric noise emitted by a single poorly designed network device or a summation of network devices is the main issue. I don’t think, in general, having fewer network devices is better or best. Logically to me, simply decoupling and/ or reducing electrical network noise is paramount. So whatever it takes to achieve lower noise needs to be done. Of course starting with a device that is designed to limit unwanted noise is key. I respectfully disagree with @mswale that the use of fiber optic is not good, generally speaking. Used wisely, fiber optic connections can be an effective tool at separating/ isolating noisy devices from the DAC. (this topic has been discussed over and over on AG). Sorry to bringing it up again. 

Again, digital domain is vastly different over analog signals. CPU's will not put any noise in the digital packet. Digital packets do not have a concept of noise. Never in my 30+ IT career has any network or computer issue been related to noise. Even in factories where computers are controling manufacturing robots.

Not sure where "decoupling" networks came from. Outside of Audio, this is not a thing. Never said fiber is not good, in fact it is the "best" network transfer method. Would guess around 80% of networks are fiber. Fiber is also the most expensive! If you have any run over 100ft fiber will work better. If you can end to fiber, I would. But when a normal fiber cable with out SFP's are $300, then another $300 for each end SFP it gets expensive quickly.  Air-gaped networks are a thing, but is all about security, and isolation. 

Maybe someone needs to do some packet captures, read the packets, also put an oscilloscope on the cables to see if there is any "noise" on the cable. Not saying it's not there, that it's not a packet transfer issue. If this was a thing, research labs, hospitals, manufacture, would all try to fix that issue.   

 

 What commercial switch do you recommend

Also, processors might not produce physical noise but they emit EMI. The heat from a processor inside the enclosure as well as the emitted EMI impacts other components an in turn adds noise to the output digital signal. Yes for data transfer it doesn’t matter. But it does impact streaming music. 
I just can’t figure out how it could if there is no physical connection between my roon core and my dac. It’s all done using mesh network. 

Cisco, Brodcom, Brocade, Ubiquiti, HP, but if you don't know how to configure them, they are useless. A "good" 8 port switch will start around $800. 

Everything that has current flowing through it will have EMI, it's a byproduct. CPU's use such low voltages, that it will not have an effect on things around it. What can make a difference are the computers fans kicking in, they produce a ton of noise, both physical and electrical.  But not sure this is affect processing, or affect anything the CPU is processing. 

You are not outputting a digital signal, you are outputting digital packets. The packets contain the data for the DAC to produce a audio signal. The DAC is in fact a computer. 

Home mesh networks are crap. Really wish they would not sell them. Almost all would be better off with a repeater in a couple spots over cheap mesh. To do mesh properly you need really good equipment with a base-station that has all the algorithm to handle hand-off, priority, and switching. Talk about noise, if you use a WiFi signal meter around the lower end stuff, it's just not good. 

On WiFi everyone wants isolation, well, if you are using WiFi, you are isolating your device. Direct connecting is almost always best.

@erik_squires think he is nailing it.

@mswale

I feel it’s important I clarify what I mean by “decoupling” with regards to hifi music streaming. For Standard data networks or WiFi, this does not matter. 
 

I view the chain of devices + cabling that run from outside your home to your Dac as typically connected via a copper wire (especially shield cable). That wire carries data packets AND some amount of electrical line noise derived from EMI/ RFI and/ or noisy devices. Decoupling, to me, simply means breaking the copper wire transmission connection of electrical “noise” carried from device to device. This is when galvanic separation/ fiber optic comes into play. Let be clear, electrical noise is not imbedded in the data packets, it’s the potential hum or ground loop electrically charged through the copper wire. 
 

The less noise or electrical hash that enters your DAC the better. Less noise contributes to darker background/ lower noise floor. 
 

I hope this helps. 

Long time Audirvāna user on a PC usb out to Pontus 2 DAC 

Pontus DAC was a big upgrade for me

by the way Audirvāna by passes all the computers audio systems and talk directly to you DAC via usb

i have now replaced the Pc and Audirvāna for a Raspberry Pi with Moode Audio software powered by a PurePi 2 with signal out via  a Pi2aes hat providing I2s out put

this system is maxed out at 24/192

all my file are 16/44.1 and passed via I 2s to Pontus 2 DAC at the same level

this combination is significantly better than Audirvāna and PC

 

i still prefer the Audirvāna interface but more than happy to give it up for the upgrade in sound

 

The rest of my system includes a Schitt Audio Freya S ( non tube ) preamp out to a Decware Torii Jr amp the to La Scalas