Schiit Vidar - Sensitive to USB noise?

[Yawnny]

Hey all.

I've hit a brick wall with my USB noise issue that has been introduced since I added the Schiit Vidar to my setup a couple days ago.

Only when using a USB Dac and Vidar do I get usb chirping/hissing/intermittent clicks/squeels

Using a USB DAC with an SMSL SA50 Class T amp I get Dead silence.

For troubleshooting, I'll hear the noise, unplug the USB cable from my Modi3+.. boom, dead silent
I'll take USB out of the equation by plugging my old school iPod Classic into the Nero Pre Amp.. beautiful silence.

Plug Modi3+ or SMSL Sanskrit 6th Ed back in.. chirping/hissing/ usb noise..

Is there something about the way Vidar is built that picks up on USB interference so much so then a little cheapo Class T SMSL SA50 amp?

Some Info about my setup:

Pre Amp: Audient Nero Monitor Controller (Have also tried Schiit SYS, Pre Outs from Audient ID4 interface, and 3.5MM out from the Macbook Pro)

The 3.5MM out from Macbook Pro introduces electrical noise with the Vidar, though not as bad as a USB Dac does

Source: Modi 3+ > 2018 Macbook Pro (Also tried SMSL Sanskrit 6th into Macbook Pro, as well as both the prior DAC's and a Windows 10 Desktop)

Here's some more things I've tried without success:

* Modi3 + > Powered USB Hub > Macbook Pro (or Windows machine)
* Swapping Audio Cables (RCA to RCA, and RCA to TS - lengths 6ft - 15ft)
* Swapping Power cables for the Vidar
* Phone is not near by (to try and cross off wifi interference)
* Ferrite Cores on Audio + Data (ie: USB) + Power cables
* Touched the top of the modi and Vidar to see if that changed the interference sound - it did not
* Made sure the USB Hub of the macbook Pro doesn't have the charging cable plugged into it
* Ran Macbook Pro on Battery only - same issue


I continue to throw money at this setup, (ie: waiting for a Topping D10s to show up to go Optical Out into the Modi, taking USB out of the chain again, looking at the Ebtech HumX, etc..) but really I could just go back to the SMSL SA50 and be dead quiet.. but then I get distortion at higher volumes - the 'lil guy just can't hold its weight.. plus I just love the look of the Vidar!

It seems that the USB power of any of these DACs is really spotty, and amplified from the Vidar somehow? Am I missing something obvious with how the Vidar is set up, or is Vidar just built in such a way that it's bringing out all these flaws with USB devices and EMI in general?

all insight is much appreciated!

 

[dfuller]

I wonder if perhaps you're running into a ground loop?

 

[Yawnny]

I wonder if perhaps you're running into a ground loop?

Indeed ,this is the path I'm going down right now. I had lost some hope when I read that ground loops shouldn't exist if all devices are plugged into the same strip, but perhaps this is wrong information. I also plugged one of those tools that tell you if there's an open ground in the wall receptacle, which there doesn't appear to be.

I did have a bit of a breakthrough this afternoon while troubleshooting.

I put my ear up to an older ethernet switch I had running into my Macbook. The ethernet switch was giving off that "electrical garbage" sound, so I unplugged it and.. wow, the random chirping/varying electrical noise actually went away.

Now I'm just left with more of a constant "buzz" from the tweeter, and a constant "humm.. lower freq" from the woofer.. which again points us in the direction of ground loop.. though the device that kicks in the "Buzz + Hum" are the USB Dac's, where the USB interface cable seems to be the culprit. When I'm using my iPod classic 3.5MM out to RCA in on my Pre Amp the sound is clean as a whistle.

Using the power adapter for either the Mod 3+ or SMSL Sanskrit 6th don't help the buzz + hum. Nor does plugging either DAC into a TP-Link powered USB Hub

I've ordered up a Topping D10 to bypass the USB portion and go USB > Coax or Optical from Topping into Coax or Optical on the Modi.. I'll see if this works.. tame the damn USB noise beast.

I've also ordered up the iFi iDefender+ .. though I'm still unsure if "breaking the ground" on a USB cable is bad news for my equipment? I'm at least going to find out if it eliminates the Buzz/Hum

Again, the USB Buzz/Hum only appears through the speakers when using the Vidar as the power amp.. with the SMSL SA50 it's all dead silent.. I wasn't expecting to throw more money after getting the vidar.. especially since my cheapo T class amp didn't have the issue.. but my troubleshooting bones in me can't help myself..have to get this figured out.

Note The SMSL SA50 does not have a ground plug, it's only a 2 prong adapter going into a 2.25" Wide by 5" power brick.. so maybe the ground is still the Vidar's reasoning for picking up the USB noise, even if it's not a ground loop being that it's plugged into the same Furman strip as the rest of my gear? Am I even thinking about ground loops correctly here? Just a thought.

 

[spacebar]

This man had some issues with his raspberry pi and noise. Maybe you get some useful information from it. https://www.raspberrypi.org/forums/viewtopic.php?t=46886

this is one of the replies:

You are using unbalanced inputs. Therefore you need your Earth to be a true Earth.

If you used a fully balanced input circuit, then you might manage to get it to work without a true Earth.

Shielded cable only works if the shield is connected to ground. Coaxial cable can be used as a balanced transmission line, but that is a different mode of operation, with its own black arts. Shielding a cable works by preventing interference from reaching the inner conductor. A transmission line works by having the same interfering signal on both conductors and subtracting one from the other. You have a half-and-half condition. I'm not enough of an electronics engineer to guess what will happen, but I'm not surprised that it doesn't work.

Operational Amplifiers do not have balanced inputs -- the two input terminals are individually required not to exceed the supply rails and any slight differences in input impedances will cause the noise not to cancel.

An RMS multimeter will tell you the RMS voltage, and if it is very good it might even tell you the right RMS voltage (cheap ones assume sine waves), but it is the peak voltage that will cause the circuit to fail.

If you need this circuit to work without an Earth connection, try connecting the cable shield to GND.

 

[spacebar]

This is from a raspberry pi psu. This is not my area, but there are some smart people here on ASR that might explain what’s going on.

And this is after with a filter

 

[Yawnny]

This is from a raspberry pi psu. This is not my area, but there are some smart people here on ASR that might explain what’s going on.

Thanks for tracking down this reference!

With what I can understand in this statement, I don't see how my SMSL SA50 (also unbalanced) would not grab the USB buzzing, and the Vidar would, but I'll admit I don't see where the info applies to me and where it doesn't with this specific quote you brought up, so I could be missing something.

I started researching how to ground a cable shield, and it looks about medium level difficulty for how far I'm looking to go, but knowing me I'll go down the rabbit hole enough to try doing this.

A lot of that thread also seems to give advice on how to ground from the circuit board itself, so not as viable in the situation of the Vidar (for me).. but it does give some insight that the Vidar may not be grounded as best it could be on the inside.

I'm also confused how even with the Macbook Pro on battery, there's a loop being created.,.but again this is most likely my ignorance.. I was thinking if the Macbook Pro is on battery, there's a reduced chance for any sort of ground loop because the Laptop isn't plugged into the Mains.

I'm also surprised that Mod3+ doesn't do anything for the noise (comparing to my SMSL Sanskrit, and straight 3.5 out of the MBP).. seeing as "Unison USB" is advertised as proprietary tech designed to clean up noise, and a reason why the Wyrd USB Decrapifier was discontinued.

I'll make sure to report back with how the Topping > Modi via SPDIF > Pre Amp goes! As well as the Ifi Defender+ results.

I'm gonna keep perusing this Raspberri Pi thread with a hope that something seems like a viable option for me to try.

One interesting thing to note here.. I found this YouTube video reviewing the iFI iDefender 3.0 and he mentions (at 0:42 seconds in, which is the time linked in the video below) that he was aiming to clean up noise that was introduced when paired it with his Vidar.. I just stumbled upon this not expecting for the same amp to be used, to my surprise!

This is starting to seem like there's something inherent with the Vidar that makes it super sensitive to noise caused by USB DACs.. again, with my cheapo SMSL SA50 this same setup is silent as can be.

I really appreciate the help with this and will keep everyone updated!

 

[Berwhale]

With what I can understand in this statement, I don't see how my SMSL SA50 (also unbalanced) would not grab the USB buzzing, and the Vidar would.

Because the Vidar has a safety ground connection (3 pin mains power input), but the SA50 doesn't (24v DC input). I recently introduced a ground loop in my system by swapping my Tannoy Reveal 402 monitors (without a safety ground) for iLoud MTM monitors (with a safety ground). I solved the issue with a cheap Nobsound USB Isolator: Nobsound USB to USB Isolator Module Audio Noise: Amazon.co.uk: Electronics

I bought an iFi iDefender 3.0 at the same time (at three times the cost), but it did not fix the issue, so it's gone back to Amazon for a refund. My understanding is that the iDefender just tries to isolate USB power, but not the data lines. The Nobsound uses an Analogue Devices chip to fully isolate both power and data lines, however, this does limit the USB transfer rate to 12Mbps. This means that audio is limited to a 96Khz sampling rate, so you wouldn't be able to play any higher bit rate files directly (e.g. via ASIO). I EQ in Windows using EqualizerAPO, so this limitation is irrelevant to me.

 

[spacebar]

Hope you find a solution

I have an ongoing issue with noise from raspberry pi 4 and my router. 2 electricians came by and they don’t know what’s going on. So now my power is being monitored with a box. Hopefully I’ll get some answers.

 

[Yawnny]

Because the Vidar has a safety ground connection (3 pin mains power input), but the SA50 doesn't (24v DC input). I recently introduced a ground loop in my system by swapping my Tannoy Reveal 402 monitors (without a safety ground) for iLoud MTM monitors (with a safety ground). I solved the issue with a cheap Nobsound USB Isolator: Nobsound USB to USB Isolator Module Audio Noise: Amazon.co.uk: Electronics

I bought an iFi iDefender 3.0 at the same time (at three times the cost), but it did not fix the issue, so it's gone back to Amazon for a refund.

Excellent, this jives with my understanding of why Vidar is introducing a "hum/buzz" whereas the SMSL SA50 does not.

If the iFi iDefender (say that 10x fast amirite?) doesn't do anything i'll definitely be sending it back.

Looks like I'll snag one of those Nobsound USB Isolators as well. Shipping is going to take almost 2 months by the looks of it for me in Canada, but for the price it seems like a great piece of kit to have around.

I'm also gonna order up a Ebtech HumX to attach to the Vidar and see if that helps.

Does anyone know if the iFi iDefender is doing something "sketchy" (from the perspective of equipment safety) with bypassing a USB ground? I know if it wasn't USB power then bypassing a ground with a cheater plug isn't a way I'd want to go (in a lot of Canadian provinces this can kiss insurance good bye). I wasn't sure if the iDefender is effectively doing the same thing, but for USB

 

[Berwhale]

Excellent, this jives with my understanding of why Vidar is introducing a "hum/buzz" whereas the SMSL SA50 does not.

It's not fair to say that the Vidar is introducing the hum/buzz (although this may be how it feels), the Vidar is just providing a pathway for the noise to travel though the USB/audio chain to earth. When I disconnected the USB connection to my DAC and the noise from my MTM's disappeared, I immediately stopped blaming them for the issue.

 

[Yawnny]

It's not fair to say that the Vidar is introducing the hum/buzz (although this may be how it feels), the Vidar is just providing a pathway for the noise to travel though the USB/audio chain to earth. When I disconnected the USB connection to my DAC and the noise from my MTM's disappeared, I immediately stopped blaming them for the issue.

You're exactly right! Re-reading what I wrote that's not right at all for me to say that. I've even proved this myself by unplugging USB from the MODI (leaving me with just Pre Amp to Vidar) and witness the Viar being dead silent.

Thanks a bunch for the perspective.. really helps me grasp what's going on!

 

[Yawnny]

Another piece of knowledge I came across is that it seems like I have to break the ground loop from the source device causing the issue (ie: USB Dac), as opposed to on the Vidar (the other side of the ground loop). I say this because the Ebtech HumX stated it should not be used on Power Amps. Not saying Vidar is the cause, but more a component of the ground loop..along the "pathway" of the loop, if I'm not mistaken.

I'm just putting this here to state I won't be trying the HumX

It seems like another possible solution could be to run a Hum Eliminator (also from Ebtech), which seems to switch between balanced/unbalanced, so the pre amp gets balanced somewhere along the line.. it seems like I would run the Hum Eliminator between the offending piece of gear (ie: DAC) and the Pre Amp

Just putting the above here for reference.. gonna see how these USB "isolator" type of devices work first.

 

[raif71]

Darth Vidar is not amused

 

[Yawnny]

Update here with my testing:

both the iFi iDefender 3.0 and the Topping D10s showed up today



The iFi iDefender eliminates some noise, but introduces a higher pitch noise than the noise I'm looking to eliminate. The high pitch noise volume seems less, but the higher frequency cuts through the silence more. Needless to say I will be returning this

The Topping D10s I had high hopes for using as a SPDIF pass through to any of my DACS.. but, unless I'm missing something obvious, the pass through simply isn't working (defective unit perhaps?)

The Topping D10s works when using the unit as as DAC, into my Pre Amp.. but running either Optical or Coax SPDIF out of the D10s into either the Modi3+, SMSL Sanskrit 6th Ed, or the DAC stage of my Nero Monitor Contorller, doesn't work.

I've ensured that either Coax or Optical is selected in the dac, that the output device is the D10s, that volume is turned up on the Pre, in the software, and in the player, and I've rebooted just to be sure. Tested on both my Macbook Pro 2018 and Windows 10 desktop.

Maybe I have a defective unit.. I don't see any obvious switches to toggle between using the outputs or not.

For the heck of it I installed the driver when on my Windows PC but that didn't kick in the SPDIF outputs either

If anyone has any thoughts, I'm all ears, otherwise this is getting returned tomorrow with the iFi (god the rabbit hole that purchasing new audio hardware gets me into.. can't wait to just enjoy music again )


For reference, here's the email I sent Topping:

Hello!

I hope all is well. I’m reaching out in regards to the SPDIF outputs not working on the Topping D10s I received today.

I’ve tested the Topping D10s as a standalone DAC and I get sound through my Pre Amp > AMP

I purchased the D10s to be a passthrough to pass SPDIF to my other DACs, but the SPDIF out isn’t giving me sound into either of my 3 DACS

I’ve tested with three DACs across Windows and MAC:

Schiit Modi 3+​

SMSL Sanskrit 6th Ed.​

Audient Nero (DAC stage)​

I tested both COAX and Optical SPDIF out, and made sure the appropriate option was selected on my DAC (ie: making sure USB wasn’t selected)

My DACs are powered from the wall

I confirmed that the sound output in my OS is set to the D10s

The screen lights up on the D10s and shows me my sample rate , but no sound comes out of my speakers. I confirmed audio is turned up on my Pre Amp and that all other sources play sound, even when switching back to the D10s as a DAC (not just a passthrough)

Is there something I’m missing here? Any help is appreciated.

Thank you!

 

[dfuller]

I had lost some hope when I read that ground loops shouldn't exist if all devices are plugged into the same strip, but perhaps this is wrong information.

All it takes is a voltage potential between different grounds. This is very easy to do if something has a 3 prong and something else doesn't (or if it isn't referenced to the same ground).

 

[Yawnny]

Further Update here:

I actually managed to find the source of the additional noise (over and above the minor Hum the Vidar introduces, which I think is normal)

Turns out my desktop PC + dimmer switch were the last two that were causing havoc with my USB DACs

My desktop PC, even when shut off, was causing interference when plugged into the same Furman strip as my laptop and amp.. I thought forsure I had checked disconnecting it before, but apparently not!

I also tried balanced cables from my ID4 interface into the Balanced inputs on my Pre Amp.. a very slight reduction in noise, but this was before I got rid of the bulk of it by unplugging my Windows desktop.

ALSO.. my dimmer switch was introducing the "buzz" i heard (over and above the "hum").. so I'm gonna replace with a simple "on off".. I don't need a dimmer switch because I'm using Phillips Hue bulbs that can dim from the app.. so pointless having this switch here

I still don't know why the Topping D10s SPDIF OUT didn't work, but at least I can save myself $130 CAD and return it without thinking that was my last hope.

Vidar itself (ie: nothing plugged into the inputs of the Vidar) gives off a very minor hum through the speakers, but I think this is just normal transformer hum? I can't hear it from 4ft away (my listening position - a studio setup)

Either way I'm quite happy with the progrss I've made so far, disconnecting, reconnecting, and finally on to something listenable.

I still have the $25 Nobsound USB isolator which I'll try.. but at this point my Modi3+ doesn't add any additional noise over and above what the speakers sound like when it's only the Vidar running with nothing plugged into it.

 

[spacebar]

I dunno, but did your dimmer have the buzz before you used the Vidar? Could the vidar interefere with your dimmer so you are now bypassing the actual problem by replacing the dimmer with on/off switch.

Have you tried to unplug your Hue psu to see if that do anything?

 

[Yawnny]

I dunno, but did your dimmer have the buzz before you used the Vidar? Could the vidar interefere with your dimmer so you are now bypassing the actual problem by replacing the dimmer with on/off switch.

Have you tried to unplug your Hue psu to see if that do anything?

Depending on the bulb that goes into the dimmer (ie: a non hue bulb as I haven't replaced all my lights in my studio yet - none of the ceiling lights have been replaced) the bulb often buzzes, but I've never had the buzz feed into the speaker before but the only Amps Im comparing to didn't have grounding plugs, so the buzz wasn't brought in seemingly because of that.

I honestly do not use the dimmer switch at all.. 100% haven't used the dimming feature for years (even since getting Phillips Hue).. the hue bulbs are all in lamps on the side, not in my ceiling.

The phillips hue power doesn't add noise but this is something I tested early on with my troubleshooting, just to make sure it wasn't casting any unwanted wireless noise

Switching off all my ceiling bulbs the buzz disappears through the speakers.. the one bulb by my right speaker buzzes pretty bad as well and always has. I tested taking out the bulb and turning the switch on, and even just having the light switch "on" even with no bulb in that speaker introduces buzz through the speaker.. so getting a non buzzing bulb won't solve the issue, going to just replace the dimmer switch which I have no issue doing.

The "actual problem" is noise out of speakers, and I've been getting less and less noise the more I strip away and test, so I don't see this as bypassing the problem of unwanted noise in speakers

I emailed Schiit to ask abut acceptable hum, just to get some more info:

snippet of my email to Schiit, for reference:

...This bring me to my final question (I think).. how much hum is normal coming through the speakers with only the Vidar connected (nothing in the inputs of the Vidar).. is a little bit normal? How much is normal for hum from the Vidar chassis itself?​

​

For reference I sit 3.5-4ft away from my speakers (sort of a studio monitor desk setup).. and Vidar is 2.75 FT away from me on a night stand top​

​

Thanks again!​

 

[Yawnny]

Another Update:

I tore out the ground plug from one of the power cables I had to use on the Vidar - just for testing, not using permanently - and all hum, even when the "hum culprits" such as USB Dacs and my Windows PC were connected, all went away through the speakers.

This leads me to believe that the Hum X by Ebtech will work here! (based on their video describing what sort of hum it eliminates)

I reached out to Morely (who now owns Ebtech) and Bill from there let me know it's actually fine to use the Hum X on the power amp as long as the max power draw doesn't exceed 720 watts of draw

From Bill

The Hum X can be used with ANY piece of gear that is rated BELOW amps (720 watts) of current draw.​

Does that help?​

The Vidar maximum power output is 700 Watts (as per Schiit website).. so should be fine with the Hum X

I should have the Hum X by mid January and will update peeps here.

The only thing left is the minor hum from 1ft away coming from the Vidar chassis itself.. I may try the Emotiva CMX-2 to clean that up.. will also let this thread now how that goes.

 

[Yawnny]

Hi everyone!

Long time no talk.

I wanted to follow up on this thread to let you know how my solutions worked out.

Here's what the final cure looks like to solve both the ground loop buzz/noise I was hearing from the speakers, and the varying hum I was hearing from the Vidar unit itself, with a Hum X going into an Emotiva CMX-2

• Hum X solves the varying electrical noise and hum coming from the speakers depending on what grounded equipment is connected
• Emotiva CMX-2 cleans up the DC on AC lines issue I was having, which caused lots of varying levels of hum from the Vidar. Now there's only the slightest 60hz murmur if my ear is literally against the unit, where-as before you could hear it from a metre away in a dead silent room.

I wanted to paste a portion of my email thread with Bill from Morley (the company who now owns EbTech) in regards to safety using the HumX. I reached out because their disclaimer about not using on Power Amps had deterred me initially.

(answers from Bill are in Red)

I'm going to be placing the Hum X at the end of my power amp plug (I tested with a cheater plug - testing only - and the hum through my speakers went away, so It sounds like i'm on the right track with getting the hum X)

I do have some safety concerns after doing research and want to confirm a couple items, for when you have the time.

we talked about the device being safe for power amps earlier - then I saw a picture from Ebtech stating "do not use on power amps" - which seems like a mixed message, so want to make sure I'm not missing some safety concern (given that the power amp output is 2 amps.. so within the 6)

We put that disclaimer on the box so it makes people check to see if they can use it at which time we remind them about the 6 amp (720 watt) limit.

If - in theory - the Hum X "blew" due to exceeding the current draw, would I get an indiciation that the device blew ie: the power amp shuts off? I just want to make sure that I don't run the risk of running the device without a ground, thinking that everything is working great.. I see there's a red LED on the device, but if the LED itself goes out without the device breaking, will there be another indication should it fail?

If the unit fails, the LED goes out and the unit no longer passes power

Bill's general agreeance on equipment that isn't grounded when it should be

If it is a piece of equipment that ultimately ends up getting touched by a person (Guitar amp to Guitar Player, bass amp to bass player, PA System to Microphone to singer…), then those people would be susceptible to a shock should there be any grounding issues or power surges. Basically the rule of thumb is NEVER MAKE A THREE PRONG PLUG INTO A TWO PRONG PLUG BY WAY OF A GROUND LIFT ADAPTER

Awesome! To be ultra clear: If the unit fails, the LED goes out and the unit no longer passes power)

This would mean that not only does the Ebtech not have power, but it’s not going to act as a pass-through for the power amp either, meaning the power amp would shut off, correct?

Yes, if Hum X fails it does not pass power so whatever if plugged into the Hum X shuts off too.

END THREAD

Bill at Ebtech was super helpful!

Anywhoo.. I hope this journey helps someone that decides to stick with the Vidar should they hear some noise from the unit, or if this is their first time working with a ground loop caused by a power amp. This did mean there were some hidden costs, but that's not really the Vidar's fault, It helped me learn a lot about cleaning up signals, and I still had some money to spare to get everything as noisless as possible, so it didn't break the bank. I am extremely happy with the end result and just as happy with the knowledge gained in the process.

Later!