Tubes Asylum

Questions about tubes and gear that glows. FAQ

Use this form to submit comments directly to the Asylum moderators for this forum. We're particularly interested in truly outstanding posts that might be added to our FAQs.
You may also use this form to provide feedback or to call attention to messages that may be in violation of our content rules.

You must login to use this feature.

Inmate Login

By default, logging in will set a session cookie that disappears when you close your browser. Clicking on the 'Remember my Moniker & Password' below will cause a permanent 'Login Cookie' to be set.

Moniker/Username: The Name that you picked or by default, your email. Forgot Moniker?	Examples "Rapper", "Bob W", "joe@aol.com".
Password:	Forgot Password?
	Remember my Moniker & Password ( What's this?)

If you don't have an Asylum Account, you can create one by clicking Here.

Our privacy policy can be reviewed by clicking Here.

Inmate Comments

From:
Your Email:
Subject:

Message Comments

Original Message

RE: Whistling Tube Question

Posted by bob_ on June 28, 2020 at 04:07:02:
Hi,

I'vo got exactly the same problem. One of my NOS 12ax7 gives me the same squeaky noise with some hum. It lasts for about 10-15 minutes after powering the amp on, not the whole time, but is random sequence, like: 1 minute of whistling, than 10-30 seconds of silence, again few seconds of noise, and again few dozens of seconds - silence...and so on ...
I tried to clean the pins with isopropanol but that did not the job. Do you think it is a good idea to gently use a very fine sanding paper? Like 1000 or 2000 size?