USB Nervosa Thread Decrapifiers, pro interfaces, and bears oh my

Excellent, not everybody does. Please accept my apologies.

I am using Linux Mint, with PulseAudio disabled and a custom ALSA configuration.

I have an M-Audio soundcard on the way and plan on comparing the RCA output of that (using an RCA to BNC cable) with the TOSLInk output of my Elfidelity card.

 

Okay, I received my M-Audio Audiophile 192 soundcard today and I have connected it to my Gungnir Multibit with a Belden 1694a RCA 1.5m cable. Unfortunately, as soon as I switch to the RCA input on Gungnir Multibit, "The Buy Better Gear" light illuminates. It does not sound good.

What could be the problem? I thought pro soundcards were supposed to be better quality?

I've used the cable with an RME 9632 and had no problem with that, so I know the cable is good.

Many thanks.

 

How are you driving the card?

If it's from Linux, then there's all sorts of possibilities.

Some pro-cards have different output clocking options which don't, necessarily, hardware-default to using the on-board crystals (sometimes this is desirable for multi-unit sync purposes). Or they might, and an unofficial driver might inadvertently flip that option off. This is more likely to be the case if the thing has a clock-input option. Standard drivers for supported operating systems generally set saner/correct defaults.

It could also be outputting something other than simple, pure, S/PDIF which, again, could be down to odd hardware defaults or bad behavior for drivers not built properly and to explicitly support the card in a given environment. Lots of these types of cards have inputs/outputs that can do multiple duty. There's no enough detail on the product page to know for sure.

And there are hardware possibilities as well, including contact between any part of the S/PDIF connection and the card bracket (test by removing the bracket), it being a faulty card, or even it just being one of the many "pro" cards that are, in fact, complete shit. That's rarer than "gamer" class sound cards being nasty for this sort of thing, but it absolutely still happens.

So, if you haven't already, the first thing to do is try it in a machine using a supported OS and drivers (via ASIO) and see if that helps.

 

Yep, using Linux. Bit of a pain to get at the Windows machine, but I will see what I can do. Thanks for the tips @Torq .

 

There's a couple of replies on the Linux Mint forum, but maybe you've read them already? They're for the 24-96 card but maybe solutions apply to your card as well...
In any case, maybe that forum could give some support.

https://forums.linuxmint.com/viewtopic.php?t=51045
https://forums.linuxmint.com/viewtopic.php?t=110841

EDIT: please feed back any info you might find, and/or solutions, so that other users can benefit. Good luck!

 

The card physically won't go all the way into the slot on the Windows machine. I think there may be something wrong with the bracket. It is bowed slightly and appears to be a tiny bit further away from the pcb at the bottom compared to the top. I managed to insert it in Linux machine okay though. I will have another look.

I bought it off the 'bay. It was new and still sealed.

Some pics: https://drive.google.com/open?id=0B5Txh-8tLqixQUFaclNLRnJXSDg

EDIT: Just checked and it doesn't go in properly on my Linux machine either, just enough for it work.

 

I've had this issue before, the card is oddly shaped at the bottom so it doesn't sit right. If you can't return it you may have to dremel the bottom of it here:



If you don't have a dremel and want to hack at it, you could cut it with wire cutters.

 

That bracket looks like every-third PC card I've had come through my hands. If it's not a length issue, then just bend the bottom part straight and it should go in fine. Damn things are only made of monkey-metal anyway, getting them NOT to bend seems more of a challenge.

 

I just bent the end straight with some pliers, very easy. But the "Buy New Gear" light still comes on in Linux though. Will try Windows next.

 

Ok, so. I've read the whole thread. If I'm honest I'm a bit more confused than when I started. The advice on the first post is good. I have some questions, so please bear with me. I use a 2013 Macbook Pro as my source. I know the first post says if your DAC doesn't cost $1000 sign out of this thread. I've had my noise problem with my Mojo, my GO2A, and testing other more expensive DACs. I've been on the desktop DAC hunt for months, and will continue to be on the hunt for a few months more probably until I find the right DAC for my set up. What I don't want to happen is buy a new DAC, and have the USB noise I'm getting currently, hence this post.

1. Don't use optical out of a mac. - How come? Is it not as good as USB in this case? I've been using optical as it is noiseless, but USB has slight noise, especially when scrolling pages (weird?)
2. If I remember correctly, the Mojo and GO2A aren't galvanically isolated (please correct me if I'm wrong.) If the desktop DAC I end up buying IS galvanically isolated, will this solve my USB noise issue? (Slight Hissing, and small pops occasionally.)
3. The USB noise lessens when I unplug my Macbook Pros Charger, it is still there, but only slightly. Is the noise a grounding issue?
4. If galvanic isolation wouldn't solve the issue, which sort of product should I be looking at? Through reading the thread I kinda got the feel that iFi's USB stuff isn't the way to go? Wyrd? Uptone Regen? LH Labs Lightspeed Revive?

I'm sorry for all the questions. I wouldn't normally worry about slight hissing/pops but I'm trying to put together a pretty decent set up, and if I'm going to go to all that expense, I might as well try to get my USB output quiet. Thank you in advance for any help. I'm going to read the thread again to see if I missed anything.

 

Several reasons for this, which I talked about earlier in the thread but, fundamentally there are two big issues here. The first is that the TOSLINK emitters are of rather variable quality in the Apple laptop and Mac Mini lines (though they're noticeably better with the true Mac Pro desktop/trashcan designs), which tends to result in significant jitter. The second is that clocking, which is very important for S/PDIF based interfaces, is, from memory, PLL driven and derived from the system clock ... which is also a recipe for unnecesary, and relatively high-levels of, jitter. The combination of these factors is particularly problematic.

The noise you're hearing over USB, especially when scrolling pages (which is not particularly uncommon) is an artifact of power modulation and/or additional CPU/GPU/radio activity as the load on your computer changes (making the computer "do less" won't necessarily reduce such noise and might make it worse) what it is doing getting directly, or indirectly, into the USB power-lines and affecting the analog sections of your DAC(s).

The only way you can know if it is going to be better or worse than USB with the combination of your DAC and computer is to try it and compare it.

You might be able to eliminate this with any of a number of USB de-crapifiers. I'd start with Wyrd, if that doesn't work other options might be worth dealing it.

Mojo very definitely isn't isolated and its USB input is probably the second most sensitive to electrical noise on the USB lines I've come across. It's REALLY bad for this (only the MHDT stuff seemed more sensitive), and the results are highly audible both directly and as artifacts in the converted output.

Mojo has hiss anyway, as does the LH unit I had ... though neither should be audible with most full-size cans.

The occasional pops are more likely to be something else, probably drop-outs (which will absolutely happen if you're playing DSD128 or DSD256 into the Mojo), but it depends on if they're really "pops" or more like interruptions.

Unlikely.

In most cases this will be due to the fact that in addition to everything else, the battery-charge circuits are operating ... which adds electrical noise to the system overall. It also tends to result in the computer operating at a higher power state, which will exacerbate this (e.g. because you have the "reduce screen brightness slightly while on battery" option set in "Energy Saver" preferences).

Any of them might.

Since USB 2.0 audio is essentially immune to jitter issues, the best way to go is start with the cheapest and keep trying them until one of them fixes the issues you're having. The notion of "USB reclocking" makes no sense from an audio perspective as there is no sample-related clock in USB audio at all and ALL USB 2.0 Async DACs are effectively re-clocking their USB inputs anyway.

 

Successfully installed the Windows 7 driver in Windows 8.1 (There is no 8.1 driver). Card is recognized and can be manipulated with the mixer. The "Buy Better Gear" light on the Gungnir Multibit also illuminates in Windows (as soon as the driver was installed). The only time it goes off is if I select a sample rate of 192Khz for the output. When I play a sound the meters go up and down but no sound comes out through the headphones. The sound comes through on the headphones okay in Linux (just sounds crap).

I'm guessing the problem with the "Buy Better Gear" light is either 1) The card is faulty or 2) The card is crap. If I can be sure the card is faulty I will send it back. I would like to send it back anyway, if I can't fix the problem, but the seller does not except returns. And obviously the card is not longer new since I've been at it with a pair of pliers.

May send M-Audio a message and ask them for advice.

 

Can you provide a bit more background?

What's your playback software and the settings in that software related to your soundcard? Can you get a couple of screenshots to show settings? Just to make sure your playback software is set up to own sound output.

Except for the drivers to your soundcard, have you adjusted the windows sound settings accordingly for exclusive access to the soundcard? Screenshots help here as well.

 

@mrflibble Also, the S/PDIF output needs to be "assigned via the routing page in the mixer" according to the manual. Maybe worth checking. Patchbay/Router on the mixer.

 

I'm more of a Linux guy, I come out in a rash when I try and use Windows. I'm confident my Linux audio config is great (disabling PulseAudio makes things much simpler). Windows, after XP, seems like a hodge-podge to me.

I use DeaDBeeF in Linux. In Windows, I just tried playing one of the sounds in the Windows Sounds dialog (eg Windows start etc). My laptop is Windows 10, but obviously the card won't go in there The Windows 8.1 machine is the spare desktop. I'm very tired now, any more investigating will have to wait until tomorrow or Sunday.

There is a post over on head-fi (by joe_cool) in the thread: http://www.head-fi.org/t/407325/can-the-m-audio-audiophile-192-s-pdif-really-output-24bit-192khz

I don't know if there could be a similar issue with Gungnir Multibit?

 

I think this is more of a settings problem

Page 11-15 in the manual seems straight forward to me. Step by step

 

Regardless of anything else that shows up, the snippets of concern over whether 24-bit output is an issue can be safely disregarded - just to avoid any wild-goose chases.

The nature of the S/PDIF output format means that the actual data-rate of the connection is identical for 16, 20 and 24-bit output. The only thing that varies is how many sample frames are sent per second (i.e. the sample rate), not how big they are (the 24-bit stuff just uses some "spare" bits in each block).

It could simply be a faulty card, or one that's on the ragged edge of tolerances (or that just uses cheap and shitty crystals), at least with respect to the BBGL on your Gungnir MB.

 

I got it working in Windows, I hadn't selected the correct playback device in the Windows dialog

I played some Windows sounds and a YouTube music video. It sounds extremely broken with lots of horrible distortion (does not sound like this in Linux). I thought about trying the headphone output of the card, but that means I will have to open the sealed bag containing the breakout cable.

 

Thanks for the very helpful post

 

Can you post some screenshots of the mixer settings whenever you get a chance?
Let's hope it's not a broken card...