Start up noise?

[jlucas]

Been using my Crack+Speedball for a couple months now and it has developed a start up noise that I would swear wasn't there when I first built it.

About 5 seconds after turning it on, there is a humming noise for a couple seconds and then it goes away.
Here's a video of it:  http://vid267.photobucket.com/albums/ii297/jplucas/VID_20150228_071552756_zpsss9fixj4.mp4

Also when there is no music playing (or during quieter passages) I can hear a little soft crackling noise a couple times a second in the background. It's very soft but I can still clearly hear it with my Senn HD560IIs or my Beyer T1s.  There's no rhythm or cycle to it, just kind of an analog snow.

Is this a tube issue?  Sorry I am new to tubes.  Anything else I should check?

 

[Grainger49]

That is just the tubes heating up to operation and is very normal.  You are not the first to notice something like this after you have been listening for a month or two.  We become more critical as we listen more and more.

The crackling noise might go away when you get 50-100 hours on the tubes.

 

[jlucas]

The crackling noise might go away when you get 50-100 hours on the tubes.

Appreciate the reply.  I'm fairly certain the crackling noise was not there originally.  If it does not go away, which tube is likely the culprit?

 

[Grainger49]

This kind of noise can also be caused by either oxidation on the tube pins/socket or a bad solder joint. 

Try unplugging the tubes and inserting them a dozen times to clean off the tube pins and socket.

Is it in both channels?  If it is only one touch up the solder joints in that channel starting with the tube pin solder joints.

 

[jlucas]

Thanks, cleaning off the pins help a bunch but the soft crackling still there although less frequently.  Is there another way to do a more thorough cleaning?

I was able to borrow a set of "stock" tubes tonight from a local crackhead as he has an upgraded set now.  The soft crackling noise is definitely coming from the 5963 input tube that was supplied with my system as after swapping in his there are zero artifacts - so it's good to know I don't have to mess with any solder touch up.

Oh, and with these tubes there is still the start up hum.  Is that a function of the speedball? I ask because he says there is nothing on his std crack.

 

[jlucas]

just cause....

 

[Grainger49]

Yes, a more thorough cleaning includes a can of Deox-it and a small brush.  You can get small brushes for cleaning between your teeth.  They will work very well on the small tube socket. 

Be certain the socket for the 6080 is snug and give it a squirt of the Deox-it then scrub all around with the same dental brush. 

The tube pins can be brushed with 4/0 steel wool.  Be certain nothing stays on the pins.  The Deox-it in the socket will help keep the contact between the pins and socket good.

But it sounds, to me, like it is tube related. 

Startup hum beyond 15 seconds is not normal.  But if it is less, just don't listen at startup.

 

[JamieMcC]

Yes, a more thorough cleaning includes a can of Deox-it and a small brush.  You can get small brushes for cleaning between your teeth.  They will work very well on the small tube socket. 

Be certain the socket for the 6080 is snug and give it a squirt of the Deox-it then scrub all around with the same dental brush. 

The tube pins can be brushed with 4/0 steel wool.  Be certain nothing stays on the pins.  The Deox-it in the socket will help keep the contact between the pins and socket good.

But it sounds, to me, like it is tube related. 

Startup hum beyond 15 seconds is not normal.  But if it is less, just don't listen at startup.

Seems like a normal start up sound to me also, some tubes are just noisier on start up than others the cause could be either the input or driver tube

A scotch bright abrasive pad, 240 grit wet and dry sandpaper or one of those non metal sponge backed pan scrubbers all work well cleaning pins. with the small 9pins if you have one of those magic erasers repeatedly pushing the pins in and out of the foam sponge will work but can take a few repeats, I keep a few handy as they can also be used to clean my turntable stylus.

A dremel with a suitable attachment will make real short work of it.