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Lots of noise w/ brand new Little Dot MKIII! :(

post #1 of 11
2/6/12 at 9:50pm
Thread Starter 

Hello,

 

I just swapped out a Mister X PIMETA w/ the Little Dot MKIII and coming from the same Asus Xonar DX, I get more noise from the Little Dot on 0 than I do from the PIMETA @ max. The card does have the power cable (berg) connected. I've tried removing all cables from the pc, different cables, surge protectors, a UPS, moving it away from everything, and finally a Zune HD...from which the noise floor is exactly the same as the PIMETA, lol. So is there an issue using this amp w/ a DX? Would another sound card isolate me from the mouse/scroll/random noises better? I'm a bit disappointed. :(

 

Thanks!

 

PS. Is it worthwhile to run down to Fry's and pick up an STX? Board's an Asus P7P55D-E Pro, 4x4GB Corsair, Galaxy 580, Corsair AX750 PSU...does any of that matter or is it probably just the sound card? I am clocked up a bit w/ C1E/EIST enabled. I just think it's odd that the PIMETA sounds just fine. Gain is @ off for both switches using the Senn HD580's as per manual.

 

Edit: DX sounds a lot better than Zune HD and it's hard to hear the noises when there's music. Is this normal? Hmmm...

 

Edit2: Compared to this picture: http://img.auctiva.com/imgdata/6/6/6/8/6/4/webimg/287558739_o.jpg

 

My front tubes only have chrome tips on about 1/3rd of the top. Are they supposed to be fully chrome like the rears?


Edited by Jodiuh - 2/6/12 at 10:02pm
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post #2 of 11
2/7/12 at 7:57am

Hi Jodiuh,

 

Have you tried reseating the vacuum tubes or cleaning their contacts with a deox agent? Also, try setting the source's volume to 50% to see if perhaps the inputs are being overpowered.

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post #3 of 11
2/7/12 at 8:58pm
Thread Starter 

I have reseated them and played w/ the source volume. Neither had any effect. I have not cleaned the tubes, however using the Zune HD results in near zero background noise and certainly no mouse/GPU noises.

 

The STX doesn't change anything. The noises are still as numerous and loud as before.

 

In the end, a $2 dollar 2 prong to 3 prong adapter from Fry's completely solved the problem.

 

http://www.frys.com/product/1509948

 

So does this mean there's a ground loop problem w/ the Little Dot MKIII as I've read about here or @ overclock.net? Someone actually recommended this exact fix. I'm also curious as to whether or not this will be a problem. Finally, I sill haven't found out if front tubes should have a 360 degree top chrome tip or if 120 degrees is enough to ensure the vacuum has not been lost.

 

Thanks!

 

Edit: I have a friend who owns one of these amps as well and hopefully we can test my amp @ his place on his pc to eliminate that as an issue. He doesn't have an issue w/ the ground loop.

 

Here's a picture of the 120 degree chrome tip on the front tubes:

 

https://lh6.googleusercontent.com/-fm8yRK0GGKU/TzIEsbmiDLI/AAAAAAAABgI/xB_ikEQ08fc/s912/IMG_20120207_220009.jpg


Edited by Jodiuh - 2/7/12 at 9:14pm
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post #4 of 11
2/8/12 at 7:11am
Yes, a ground loop is a potential problem. As for the tubes, the amount of getter depends on the manufacturer. It's fine, so long as the getter doesn't oxidize white, it's fine. Keep an eye on how much getter there is: if any more getter disappears or oxidizes white, you've may have a bad tube.
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post #5 of 11
2/8/12 at 3:21pm
Thread Starter 

Unfortunately, I do not remember if the whole top of the tubes were chromed or not...I assume that's the "getter?" David from LD said it was fine, but it seems less than ideal given the pictures on the site show a fully chromed top. I will ask him if they can send me a new pair.

 

He also said it's not a ground loop problem, but that it's computer interference and I need a more shielded sound card. The STX was already fully sealed and cost $179. I really have no interest in a $399 whatever given a $1.50 adapter fixed the issue...by removing ground, lol.

 

I don't know. I'm a little disappointed in the amp at the moment. I suppose I should have done a bit more research.

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post #6 of 11
2/8/12 at 6:16pm
The getter is fine. Look at a few other amps on his site--they have the same thing. My MK IV's 5654's has uneven getter on the driver tubes. They're the same driver tubes as in the MK III. Likewise, my 6H30's, like your 6H6's, have about a third of the envelope covered in getter.

Double-check if it's the amp or not by trying other sources. Try that Auzen Forte and see if the problem persists. Also, try turning down the sound in Windows--I wouldn't be surprised if that's what it was. Start trouble-shooting.
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post #7 of 11
2/8/12 at 10:06pm
Thread Starter 
 
 
 

Thanks for the reassurance Bobsama. I've never owned and know little about tube amps, so thanks for putting my uneasiness to rest.

 

From the Zune HD it's as silent as the Pimeta. Only once I turn the volume knob past 2/3rd do I begin to hear a smooth, consistent background noise.

 

I sold the Forte awhile back, just haven't updated my sig, haha. I've tried changing speakers, analog output, sample rate, turning up/down/muting all input/outputs, disabling enhancements, the Xonar STX, unplugging extra cords, moving things around, holding the amp above my head while standing 5 feet from the computer, different cables, reinserting the tubes, different surge protectors, different outlets, etc. The noise is exactly the same in every scenario except for one when connected to my PC...using a 3 to 2 prong "groundless" adapter.

 

LD told me it was my sound card. So I replaced it w/ an STX. When I told them the STX did the same thing, but the 3 to 2 prong adapter fixed the issue, they again told me it was my sound card and I needed one w/ a shield. The STX has all the analog bits in a sealed shield...what next? Omega 2? A $400 card? Then I found this little bit in the reference guide for the amp...

 

3
Basic Troubleshooting

 
Ground Loops
: In systems where the components have multiple paths to ground, you may notice a 60Hz hum on the Little Dot output. Please only use a cheater plug power-cord as the last resort, as thiscan be a safety hazard. To resolve ground loop issues, the better method would be to use a groundloop isolator. The ideal method would be to solve the ground loop at its source by connecting allcomponents to common ground and/or have your electrical wiring checked by a professional electrician.

 
 
 
 
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post #8 of 11
2/8/12 at 10:46pm
To be honest, I don't think you'll ever get a truly silent internal sound card--and don't expect USB-powered to be any better. The problem is that even top-end power supplies are ridiculously "noisy" and that your computer is literally filled with interference. Also try plugging the amp into a different house circuit. You probably would have been better off with an external DAC instead of the sound cards--not quite as convenient but at least you can electrically isolate your audio from your computer. That said, is the noise in both cans or just one? Does it persist if you entirely disconnect the RCA plugs from the amp? Or maybe you already answered--I'm about to go to bed so I'm not gonna look at your older posts and try to figure it out.

Tube equipment is very different from solid-state equipment--expect different things.

The only thing I dislike about Little Dot is that most of their products, especially their tube amps, lack a front power button/switch. Other than that, they've been excellent to me.
Edited by Bobsama - 2/8/12 at 10:49pm
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post #9 of 11
2/9/12 at 8:13pm
Thread Starter 

Haha. Yeah, I can hear noise from my AX750. I thought about replacing it, but it's such a hassle and the PC's stable anyway.

 

Removing the plugs from the amp w/ the headphone and power cable directly into a UPS does indeed eliminate the noise.

 

My DX is old and an external DAC would be a fine option had the $1.50 adapter not worked. As it stands, I'm fine w/ that. I prefer the functionality of a sound card and am currently fussing over speakers right now anyway. :D

 

As for the power button, yeah, that sucks. It's not as much of a bummer as the rear power button on a speaker though since it's height is low and it's easier to reach over. Still in a perfect world...

 

1. Speakers and headphone amps would have on/off/volume/bass/treble/etc controls right on the front.

 

2. LED flashlights would  not be used. They would be super dim AND have a switch to turn them off...or a cover to slide over them.

 

PS. W/ the little dot turned off, headphones, rca plugged in, and music playing on my PC, I can hear music...that's a tube thing I'm assuming?

 

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post #10 of 11
2/10/12 at 7:09am
The amp didn't disengage without a source--it's the source that's inducing the interference. That said, I'd be careful about running the amp on a 2-prong--try grounding it.

Amen to the LED concern--I'd love diffusers on the front of 'em. You'd think manufacturers would provide 'em but no--few do. I ended up taping some cardstock to the front of my MK IV & DAC_I--it looks odd far easier at night. Plus, I can look at my tube glow without being blinded!

I prefer equipment without EQ controls--I rarely ever futz with them.
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post #11 of 11
2/12/12 at 12:10am
Thread Starter 
I put electrical tape over them. tongue.gif

Treble/bass isn't really a big deal. Mostly I would like power/volume on the front.
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