[Davienr]

Hey guys,
 
I recently purchased and received a Rogue Audio Cronus Magnum and am really happy with it, but it seems to pick up really bad noise from my computer (which is the main input).
 
Does anyone have any suggestions for removing this noise?
 
Thanks,
 
-Nick

 

[NA Blur]

Looking at the Rogue Audio Cronus Magnum I see there is no USB input?  If that is the case then your DAC in your PC is the culprit.  The best way to eliminate this would be to simply purchase a decent DAC like the Bithead from Headroom and have your PC feed the Bithead vis USB and then the Bithead feel the amp via stereo Y-Splitter to RCA.  Computers are notoriously noisy DACs.
 
A good DAC will reduce the noise you are hearing by at least 95dB.

 

[Head Injury]

Quote:

A good DAC will reduce the noise you are hearing by at least 95dB.

Hardly. That would mean the PC's DAC would have to have 0 dB noise. All you'd hear is noise.
 
Davienr, have you done any checks to be sure it's the computer and not a fault with the amp? Tubes can be susceptible to interference from nearby wireless equipment, like a phone. You can try a cheap external DAC like the Behringer UCA202 to test.
 
If you honestly don't have a dedicated DAC, I think maybe you should have done more research before blowing $2,000 on an amp.

 

[nagual]

Make sure all the sound stuff, including your computer,  is connected to the same outlet, and nothing else.

 

[Davienr]

Alright,
 
So, i picked up a FiiO E7 today to see if it would solve the problem, and it seems to have to some degree, its definetly still there when I turn the volume up over half way from the amp, but definetly not as bad.
 
Now, this is not a stand alone DAC, so im wondering if i purchased a higher quality DAC do you think it would remedy the problem further?
 
The guy in the store reccomended the Azur DACmagic.
 
Thoughts/opinions?
 
Thanks,
 
-Nick

 

[Elysian]

That's strange, as a good intermediary device should cut out most of the discernible noise from your PC.  That's why people buy $20 USB sound cards.  I'd imagine the E7 should be sufficient, though I use a much cheaper device to deal with laptop noise.
 
I'd like to say that a good discrete DAC would solve your problem, but there seems to be something going on.
 
What are you using for your computer?  At the cost of a good DAC, you may be better served just building a new computer.  I'm assuming you're not using a Macbook Pro, as Apple computers usually don't have the noise lousy Dell (and other cheap PC OEMs) have.  I'm pretty picky about the components I use in my system and never have any discernible noise, but I can hear noise easily from a Dell Optiplex and other budget office computers.

 

[Davienr]

Ah, Its just a typical gaming PC.
 
I can post components if you like.
 
Could it be because I have the cover off? or a mic plugged in or anything simple like that?

 

[Elysian]

No, the cover off shouldn't cause any issues.  I've left the cover off on a lot of gaming PCs to help with cooling while running SLI.  I'm suspecting a shoddy power supply and/or mobo.
 
How are you getting sound out of your PC?  PCI sound card or onboard audio?  Which chipset?  Analog or digital out (and if so, Toslink, coax, etc.)?
 
It's difficult to diagnose without more detailed information on exactly what you're doing.

 

[Davienr]

http://www.mediafire.com/?amrsz84xrkoa3nr
 
Thats an upload of my DxDiag which should have all the info about my PC.
 
My mobo and CPU are less then 2 months old, so I doubt thats the problem. No sound card.
 
At the moment im going from USB to DAC then standard headphone jack to RCA into the amp.

 

[Elysian]

Nice PC.  The issue probably isn't the mobo.  The Gigabyte Z68X should be fine.  CPU should have no effect.  What PSU are you using?  You didn't skimp on the other parts of your system so I assume you have a decent PSU.
 
If you're going from:
 
PC -> USB to E7 -> RCA to Magnum -> Headphones
 
Then I'm pretty stumped why the noise is being picked up on the USB cable, assuming there's nothing wrong with the cable.  I'm also assuming all your gear is properly grounded.
 
The only suggestion I have is make sure you're not using DirectSound for music playback, and instead try using WASAPI output through Foobar and see if that helps.  Foobar automatically claims exclusive mode when using WASAPI, so you won't be able to get sound through anything else until you stop playing music on Foobar.
 
Let us know if that helps at all.  If you plan on getting a good DAC, I'd just return the E7 and get something like a AMB gamma2 (if you don't want to build one yourself, you'll have to commission one), and use coax or Toslink for it.  There are a lot of good popular $300-500 DACs nowadays.
 
From looking at your mobo, it looks like you've got digital out.  In my experience, most DACs don't do USB very well.  The latest generation of Gigabyte onboard implementations are good, so I don't think you need a PCI sound card to solve this issue.  If you have a PCI sound card laying around, I'd plug it in and output through that, straight to the Magnum, to see if it solves your problem.

 

[Davienr]

Nah I dont have a sound card unfortunately.
 
My mobo has SPDIF output but the E7 only has standard headphone jack slots and the amp only has RCA.
 
My PSU is a Thermaltake Toughpower 800W.
 
The weird thing is, when my computer is idling/playing music the sound isnt terrible bad, its when im playing videos or games that it gets bad.
 
Would it be easier if i just recorded the sound or something?
 
Thanks for all the help by the way, I really appreciate it.

 

[acc focus]

I'm almost shure its a ground issue and offcourse a fan issue... I have the same problem when i'm playing just music the noise is not realy anoing but when i"m downloading a lot(usenet so a lot of pc power needed) or playing games my fans and hard disks spin a lot faster and the noise increases, the only thing that helped me out was conecting with spdif because there is no way the irritating sound can travel with a bitstream over light(spdif) so i asume you should get a dac with spdif on IT.... Its a fairly costly procedure but if you are willing to pay the price the end result will realy be satisfiing. Its a hissing sound you hear right? IT comes from the motors of your fans and hard disks, just try to stop some fans and listen again(i hope you are smart eneough to now how to stop a fan, and dont do this for a long time! I noticed that the fans used on video cards are realy cheap and do spin spin realy fast but also give extra noise)

 

[Davienr]

Yea, thats the thing, the DAC's with SPDIF are a lot more expensive, and if it doesnt fix the problem its kind of wasted?

 

[JRG1990]

With the E7 set the screen to turn itself off, this reduces noise also get the L7(the line-out dock for the E7) , tube dac/amps can have really bad signal to noise ratio they measure around 60db signal to noise ratio which means audiable noise, so it might be the tube amp causing the noise. Have you tried using the E7's headphone jack and see how much noise you can hear?.

 

[Davienr]

Quote:

With the E7 set the screen to turn itself off, this reduces noise also get the L7(the line-out dock for the E7) , tube dac/amps can have really bad signal to noise ratio they measure around 60db signal to noise ratio which means audiable noise, so it might be the tube amp causing the noise. Have you tried using the E7's headphone jack and see how much noise you can hear?.

Hey, I'll try to pick up the L7 tomorrrow.
 
I just plugged my headphones into the E7 and I can definetly still hear the sound.