Option for optimized performance for a single core and single zone playback [Not on Roadmap]

Not using this bit perfect test file. The test file is not music. It’s a file created by the DirectStream’s designer, that his FPGA uses to verify playback is bit perfect or not. There may be a couple other companies that do something like this, but it’s not common. It’s one thing for Roon (or any software) to tell you it’s output is bit perfect but another for the DAC to verify for you also.

I’m sure many DIrectStream owners reading this would also think it would definitely be interesting if I could hear a difference of this test file, between different software, given the test file is not music :smile:

So to be clear, the bit perfect test file was used just once with A+, just to verify it’s output (and the entire chain up to the DAC) is bit perfect. Which it is. This thread is based on observations based on listening to music in A+ and Roon.

I also don’t want this thread to turn into ‘software can’t possibly sound different’. There are enough observations out there and Danny has already hinted at a possible cause which I am familiar with also - the old Blackberry near the speaker is an extreme example but along the lines of what he is talking about. I’ve also heard the fast scrolling being heard on a nearby speaker but that was many years ago too.

I’ll test Danny’s suggestions later this weekend.

1 Like

Sorry didn’t realize that the test file was not an audible file. If you listened to music through A+ with the same settings as this test file then so be it.

If this is really the case then that implies that tiny differences in cpu can have huge differences in SQ due to electrical load/leakage and rmi. And that usb truly is a bad audio transport because of the power bus it carries and all of these tweaks that try to isolate usb power or provide clean power are in fact very important.

I am not entirely convinced … that said, I am looking forward to dumping USB and using ethernet! The usb tweak game and associated expensive accessories is crazy. If anyone has read the thread on CA about tweaking the chain with multiple clocks, switches, linear power supplies, and thousands of dollars, you will know what I mean …

2 Likes

“ExclusiveMode/HogMode/DirectMode” all are trying to do the same thing: make sure the audio stream gets to the device as it was intended, with no mixing or interfering with the signal along the way. Even IntegerMode is trying to do the same for 32 bit PCM. UPnP and RAAT are doing the same thing too.

All these modes are irrelevant… all that really matters from the software’s point of view is that your perfect bitstream gets to the DAC intact. It is my opinion that your DAC should be protecting you from interference of any sort.

If you are hearing differences between 2 bitperfect streams, then environmental stuff is impacting your DAC. Blah. The above DirectStream test file is there just to be able to measure the bitperfect delivery. Another way to test that is to play DTS files, or DSD over PCM. Neither of those will work with a non-bitperfect stream.

Roon’s core value proposition is that UX matters, and if your equipment can’t give you great SQ with modern beefy computers that give great UX, then you need to use a different architecture that Roon supports to avoid those issues, such as running a GPU driven UI on another machine/tablet, and using a lightweight networked device or a USB bridge device. Both of these techniques keep the environment very clean for the analog process (the D->A is ultimately analog), while providing the ultimate in UX.

As for A+ vs Roon on USB, I am not challenging the claim at all. I believe that people hear something sometimes in some situations with some hardware. I know how USB works, and it can be very susceptible to “noise” from various sources.

If you said the same thing about A+/UPnP vs Roon/RAAT, I would say that bold claims require bold proof, and you can keep your antecedal evidence to yourself until you have an explanation that can be reproduced and experimented on.

1 Like

Hi Danny, I’m not sure if this is directed at me, in response to the entire premise of this thread. I hope not.

But I’m looking forward to trying your suggestions later this weekend.

it’s not… You aren’t claiming that the networked stuff sounds different. If you were claiming that, then it would be.

Cool, cheers.

Having played around for several years with each of Roon, A+, JRiver and HQ Player, I have too have a slight preference for A+ in the direct connection to DAc via USB scenario. But, as Danny suggests, I found using a very lightweight endpoint and NAA solution to sound even better (allowing me to use a very powerful computer to do my processing, but separating it both through the NAA and through use of a fiber conversion to limit the ability of any noise to travel to and through the NAA to the DAC).

That still leaves me using A+ on my Macbook when I’m listening to headphones through my iFi DAC, but it is the only place I use that combination. Everywhere else the power of Roon (or the improvement brougt about by use of the NAA) wins.

2 Likes

You’re using USB connection right? Do you use any sort of ISO Regen + LPS with the USB? RFI / EMI / ground plane noise traverses from your electrically noisy computer via the USB cable to affect your USB DAC. this is why there are all sorts of products that try to clean that up.

Yep, already using an Uptone ISO REGEN + LPS-1 right before the Hugo2 (which itself heavily filters RFI and is really well shielded, per Rob Watts). The USB DAC input is well isolated.

Airborne RFI is something to consider, but the Mac housing is all metal and the DAC housing is all metal, which helps shield from RFI.

Devices with metal enclosure do not approximate faraday cages–remember, bluetooth, wifi, and air are passing in and out–at least. Computers are designed to be permeable.

In my experience, RFI produces the largest effect size of all of the “beyond bit perfect” interference mechanisms. It’s the first place I try to debug when things don’t sound right. And nearly 100% of my bad experiences with RFI have occurred in the presence of plenty of metal enclosures.

When I want to do critical listening for the purpose of evaluating gear, I take the absolute minimum amount of stuff into the middle of a room with no other equipment, and do the testing there with a pair of headphones. Ideally, just a power cable and ethernet cable connect that stuff to a Roon system in a closet far away. I don’t trust what I hear in my office–because there is so much equipment in here and I can’t hope to meaningfully control for who is radiating what.

I’ve reviewed dozens of devices since we launched Roon in 2015. I’ve seen some that like to amplify WiFi signals, some that like to amplify GPU activity, some that like to amplify RFI from the driver circuitry in my Thunderbolt monitor, and some that pick up cell phone signals. Usually when I notice this stuff, the effect size is huge–it’s not something where any would doubt the audibility. Remember back in the 90s when every amplifier would pick up and amplify GSM signals? I’ve run into some products that still do.

Of course, if a device is able to amplify interference to the point where it is unmistakably audible, it’s also amplifying lower-amplitude interference and causing more subtle problems at other times.

I want to stress-this is not just irresponsible manufacturers, and it is not just inexpensive products. Some devices that I like quite a lot, and would recommend to my friends have exhibited this kind of behavior.

There is just no substitute for physical space between the sound critical stuff and the stuff that isn’t engineered that way. The game of “making things radiate less” is moot by comparison. Yeah, you can do it to a point, and see some results, but it’s a much less interesting game.

Anyways–my one recommendation is to look into the system-level optimizations that Audirvana performs. Turning off Spotlight indexing, stuff like that–Roon doesn’t do that stuff, but you can definitely do it by hand if you want and see some of the same benefits.

I don’t think you’ll find that their communication with CoreAudio or their file handling is the source of the differences. If I had to bet–it’s the GPU/CPU load associated with Roon’s rich UI that makes the biggest difference. Not a whole lot we can do there within one machine.

3 Likes

Cheers Brian. As per my OP I am very much experienced with having networked endpoints with a powerful i7 Roon Core far away from all the endpoints. Actually I commented last year that moving the i7 out of the listening room provided one of the best improvements in the sound quality.

Having moved from a large double storey space to a small apartment I’m now down to a single Roon/Core combination in the office.

I’m very much aware there may be compromises with this setup and this may simply be one of these compromises.

A+ has to deal with the exact same setup so it may (must?) be airborne RFI due to CPU/GPU as you and Danny say. I’ll try Danny’s experiment tomorrow.

Yah, I know you’ve been around the block. I’m not sure I’ve shared my thoughts about RFI in as much detail before so I wanted to get them in writing. I think now that device manufacturers have gotten pretty good at managing USB and very good with Ethernet, this is one of the next frontiers for improvement. Can always hope…

1 Like

By the way, I know of another manufacturer who has the opinion that WiFi RFI is bad for sound quality, and says therefore Ethernet is superior. As with many audio debates, there is an opposite camp (from certain users of particular devices that have both WiFi and Ethernet input).

I’m certain most of the worlds best DAC designers will agree that RFI can be an issue and design to shield against it.

Having owned DACs designed by 2 of the best designers (Ted Smith and Rob Watts) I know from discussions with them that they design extensively to protect against the effects of EM/RFI.

At the same time, as Brian says, he has seen and heard the best come through Roon Labs for testing and still seen and heard that even the best gear out there is not fully immune.

I think it’s possible that people here are only thinking of RFI as interferring with the signal traveling down a USB cable to the DAC. We are bathed in RFI, and perhaps the sonic differences have more to do with how the RFI is interfering with the whole listening system, not just the DAC itself. I am only presenting this as a possibility worth exploring. I have neither the academic background, nor the equipment or experience to test thismyself.

Hi Mark, my DAC’s USB input is isolated (power, ground and data lines). On top of that Rob Watts will tell you he filters RF heavily.

So yes I agree, as I mentioned above, airborne RF is possibly one of the major culprits.

While I’ve known this already (I already heard the sonic improvement that comes with moving an i7 Core out of the listening space) I guess I didn’t expect to hear a difference between RFI (due to CPU/GPU loads as Danny and Brian hinted) between 2 apps… if that is the culprit here.

Danny, what kind evidence are you looking for when it comes to sound quality of Roon/RAAT?

The users gave the input can be experienced on. Have you compared A+/UPnP vs. Roon/RAAT? Do you claim that they have equivalent sound quality in your experience?

If the UPnP implementation is not terrible and the device is Roon Ready, it should be identical. If you hear otherwise, I’d be interested in a statistically relevant blind test that removes the chances of bias.

@danny,

If you did, did they sound identical?

I’ve not done this test for all the RAAT devices we have that we have certified. We normally leave the audio parts of the certifications to the hardware manufacturer. They have all done the tests to verify the SQ is there.

However, we’ve actually gone one step further, and tapped the actual bits coming out of the other side… and they are identical (obviously). Both are pull protocols, so timing is driven by the clock in the device, and not the sender.