"Wind-like" noise on start up

[Decko]

Hi All,

When I turn on my 2 watt amp, I noticed a "wind" like noise upon start up and then continues randomly for about 45 mins to an 1 hour.

What coud be attributed to this condition? Filter caps? Where do I start to diagnose/ troube shoot?

Thanks!
Decko

[Structo]

First I would try substituting known good tubes for what's in the amp.
One at a time and take a listen each time.

It could be bad solder joints or grounding as well.

But always suspect the tubes first.

Is this a new build?
Has it worked good before?

[tubeswell]

Yep what Structo said.

If that doesn't work it could be a voltage leak somewhere, (like over-soldering-ing one of the pots leaving a conductive residue between the terminals) or a leaky board if you have used an older type phenolic board (tweed disease). But check the tubes first.

[Decko]

Thanks for your response...

Yes it is a new build. I'll check all the tubes as you have suggested then the solder joints. I may have over soldered some of the flea clips. The board I used are from Allyn but I have never had a problem.

Thanks!
Decko

[tubeswell]

It could be voltage leak across a pot too. If grounding a pot input stops the noise, then try replacing that pot. 2CW

[LOUDthud]

Describe the circuit, number of preamp stages, tone/volume control and type of output stage.

Try to localize the source. Does the volume or tone controls affect the wind? Does pulling any tubes silence the wind? Starting at the input and following the signal to the output touch a .1uF cap from each grid to ground. What points silence the wind and what points don't?

[soma_hero]

I just finished a submini build, and had a similar issue. Like wind randomly coming on and then cutting out. If I jiggled the chassis the sound would go away or come back. Knew it was a grounding issue, took the perf out and flipped it over. I had made mechanical contact with one ground but forgot to solder it, so it was still making sound but was real noisy. Soldered it up and away we go!

[Jana]

I can't add much more to what has already been said—as far as technical help.

But, "wind like noise on startup," well, every morning!

Maybe your amp is begging to play songs like "Dust in the Wind?"

Come on guys, I mean, it is almost Halloween and nobody has jumped on this one yet?