Ringing from the tweeter

Hello fellow Audiogoners,

First of all, I wish all of you a wonderful holiday season filled with great listening and beautiful music, and other joys.

Now to the question. I recently noticed a faint, intermittent ringing sound coming from the left tweeter. It's audible upon powering the system up, with both the volume control turned up or all the way down, although it appears more faint with the volume up. The only source connected to the line stage is the phono preamp on Aux, but the ringing is present on all sources selected. It does disappear when the mute button is pressed on the line preamp and seemingly gets lower as the system warms up, but never fully goes away.

The ringing does not appear to affect the sound when the record is playing, but I did not hear it before and the system has not changed. The system consists of a solid state phono preamp, tube line stage, and tube monoblocks.

What do you think could be the culprit? The power line? One of the driver or power tubes, or the worst case scenario, the tweeter? And how can I isolate the culprit?

Any opinions and suggestions are welcome. Thank you.
Hi Marek,

The symptoms you've described appear to point to the line stage as being the culprit, and I suspect in particular the first tube in the signal path within the line stage.

If you can determine that separate input tubes are used for the two channels in the line stage try interchanging those tubes and seeing if the problem moves to the other channel.

Before doing that, though, it would probably make sense to interchange the cable connections between the two channels at the outputs of the line stage, to verify that the problem is caused by something "upstream" of that point. If the problem moves to the right speaker when you do that, restore those connections to their original state and then interchange the cable connections between channels at the inputs of the line stage. If the problem then does NOT move to the right speaker you will have pretty much verified that the line stage is the culprit.

Have everything turned off while you are changing any connections, of course.

All the best to you and yours as well, for the holidays and the new year!

-- Al
Sounds like a tube is ringing. Wiggle the tubes in their sockets. You can flick small signal tubes with your finger. It might stop for a while. Caution! This will send nasty sounds through your speaker. Disconnect the speaker to be totally safe. I usually just turn the volume way down or off. Never had a problem. You need to hear anyway when you find the suspect tube. If it comes back, you probably need new tubes.
Disconnect the speaker to be totally safe.
Steuspeed, note that Marek (Actusreus) is using tube power amps. As you may be aware, tube power amps (or at least those which utilize output transformers, which means the great majority of them) should not be operated without a speaker or equivalent resistive load connected. Especially if a signal is being put into them. And a loud noise transient that may be caused by tapping a tube, and probably even more so by manipulating a tube in its socket, can certainly constitute a "signal" in this context.

And of course turning down the volume control will not make any difference with respect to that concern if the tube is located "downstream of" ("after") the volume control in the signal path. As would be the case with all of the tubes in the power amps, and quite possibly all or most of the tubes in the preamp.

-- Al
Thank you for your wishes and advice. It's greatly appreciated as always.

I was going to wait for a few days before switching the interconnects since I just wanted to listen over Christmas and not tinker, and the ringing continued until some time last night when suddenly it simply went away.

I just turned the system on and there is no ringing. I guess perhaps sometimes the best way to fix things is to wait and let them fix themselves...We'll see.

Steuspeed, you may be onto something there, so if the problem comes back, I'll just make sure the tubes are in their sockets firmly, with the system off.

Happy New Year!