Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Little Dot MKIII hums
New Posts  All Forums:Forum Nav:

Little Dot MKIII hums

post #1 of 9
Thread Starter 

HELP

 

I have a new 15 hrs old Little Dot MKIII amp that has a hum. If I turn the volume  down I can still hear the hum. I sent a email to Little Dot, no response yet anyone here have any suggestions?  Thanks

 

Gary


Edited by gary ocock - 2/27/14 at 6:34pm
post #2 of 9

I can tell you what they will say, "Clean the pins on the tubes", there is some stuff called 'Deoxit' that they recommend . Personally I guess I was lucky, mine has worked perfectly from day 1 for over a year now.

You can also search on youtube, somebody uploaded a video of how to do it.

post #3 of 9
Thread Starter 

Thanks

 

I'll get some from Radio Shack and give it a try.

 

G


Edited by gary ocock - 3/1/14 at 3:41pm
post #4 of 9

Cool... looking forward to your results.

My earmax has always had a really low level ~60Hz hum.  its only a problem on black-silent passages.  I never thought to treat the tube sockets.

post #5 of 9
Thread Starter 

I think I narrowed it down to a audio tube. I discovered the hum was coming from one side (earphone). I then reversed the tube and the hum moved to the other ear. I reversed it again and it moved back to the other side. Looks like a bad tube.

post #6 of 9
Thread Starter 

I've been busy. It was a tube for sure as I purchased some tubes (ebay) and one pair Hytron JHY-6AK5 are working great.

 

Gary

post #7 of 9

Hi,

 

I have hums from Little Dot MKII only with EF95 valves. I have two MKII amps and the other one is ok with the same valves (I have many valves to test with as well, when I replace with next EF95 pair it's ok at first then the humming gets back) . Also the humming almost disappears when I touch the amp and gets worse when I put my hand in the air between the valves. When I switch to EF92 humming disappears.

Thx

Andy

post #8 of 9

Hi,

 

I have hums from Little Dot MKII only with EF95 valves. I have two MKII amps and the other one is ok with the same valves (I have many valves to test with as well, when I replace with next EF95 pair it's ok at first then the humming gets back) . Also the humming almost disappears when I touch the amp and gets worse when I put my hand in the air between the valves. When I switch to EF92 humming disappears.

Thx

Andy

post #9 of 9
Quote:
Originally Posted by sssboa View Post
 

Hi,

 

I have hums from Little Dot MKII only with EF95 valves. I have two MKII amps and the other one is ok with the same valves (I have many valves to test with as well, when I replace with next EF95 pair it's ok at first then the humming gets back) . Also the humming almost disappears when I touch the amp and gets worse when I put my hand in the air between the valves. When I switch to EF92 humming disappears.

Thx

Andy


and I think maybe it's dirty ceramic sockets, not easy to clean them though.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Little Dot MKIII hums