[jayeph]

i have a little dot mk4 w/ stock tubes which has a very audible humming sound with any of my headphones... from my low impedance grado's to my high impedance beyers

is this normal? or does this sound like a problem i should take care of?

it hums with no music, and at the same volume no matter what headphones i plug in... i'm feeding it with a d10 if it matters, my previous tube amp, the EF1 did not hum at all

u cant notice it once the music is on, but if you play the music at low volumes, you can hear the hum in the background still, it's quite annoying!

 

[HeatFan12]

Quote:

Originally Posted by jayeph /img/forum/go_quote.gif i have a little dot mk4 w/ stock tubes which has a very audible humming sound with any of my headphones... from my low impedance grado's to my high impedance beyers is this normal? or does this sound like a problem i should take care of? it hums with no music, and at the same volume no matter what headphones i plug in... i'm feeding it with a d10 if it matters, my previous tube amp, the EF1 did not hum at all u cant notice it once the music is on, but if you play the music at low volumes, you can hear the hum in the background still, it's quite annoying!

Is this normal? No

Does this sound like a problem i should take care of? Absolutely....Hum is not good no matter how you look at it. Black backround is your goal.


Before I ask about the tubes- Have you tried another source? Maybe a CDP or DVD and is the hum still there?
The D10 is connected to your PC?

Did this hum appear suddenly or was it there from the beginning?

 

[jayeph]

yes i've tried my ipod and also an old cdp, i'm pretty positive it's the amp as the hum is still there w/ any source

and yes, the d10 is connected to my comp

i bought it used... and the hum was always there, but the seller warned me about it.. just didn't know it'd be this audible

could it be the tubes? or is it something internal? i have no soldering/electrical skills

 

[apatN]

That's not normal, no.

Is the hum in only one channel? If so one of your tubes is likely causing the hum.
If not, then either both tubes are dying or something internal is causing the humming.

 

[jayeph]

the hum is evenly audible out of both channels..

am i out of luck if it's the internals?

 

[apatN]

Could be pretty bad as you probably can't fix it yourself. You really should ask this question to David from Little Dot. He is very helpful.

 

[atbglenn]

Definitely let David know about your issue. He's very responsive from my experience..

 

[koven]

yeah, like others have said.. definitely sounds like something's wrong

 

[jayeph]

thanks guys, what's the best way to reach David? could someone provide his email?

 

[atbglenn]

You can try his eBay account

Click Here

 

[mugtastic]

you often have to lift the ground with ld amps - i use a 2 prong "cheater" plug on mine. i've been told it's perfectly safe by experts.

you can also get a ground lift cable from radio shack.

 

[jayeph]

thanks for the link atbglenn

david just told me it was a ground loop, is that what you're referring to mugtastic?

 

[mugtastic]

Quote:

Originally Posted by jayeph /img/forum/go_quote.gif thanks for the link atbglenn david just told me it was a ground loop, is that what you're referring to mugtastic?

yes

 

[jayeph]

could you explain what i need to do? ive never really done electrical work or anything

not sure how to even find the ground..

 

[atbglenn]

Get yourself one of these from your local hardware store.