|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
12.73.121.162
In Reply to: MICROPHONIC TUBES? posted by BOONIERAT on March 31, 2007 at 15:29:34:
With no signal tap it , if there is noise at speakers it is microphnic.
If it is showing up while listening to music replace.
Tazsmonn "The Cat Herder".
W66th.St./Richfield/Minneapolis/MN/USA
Cats are good room treatments, you should have 2 Or 3.
My detracters have never heard my system.
Follow Ups:
"With no signal tap it , if there is noise at speakers it is microphnic."May I humbly disagree? ALL tubes are microphonic to some degree, and perfectly healthy tubes that work just fine will often (usually?) make noise if tapped. If the noise dies immediately after the tap stops the tube is likely fine.
"If it is showing up while listening to music replace."
Agreed!
You may find a tube that is "microphonic" in one socket may work fine in a different location. So you can try it elsewhere if you like.
This is true imo, all tubes are microphonic to one degree or another....some families for than others, the 6DJ8 family for instance can be a challenge ime. You should be quite careful taping on tubes while hot in the circuit....I never recommend that. That said, if you get yourself a cheap pair of headphones, Sony makes a few decent and cheap pair and get yourself something akin to the George Kaye unit (I use it and love it) although hard to find as only 220 were made by George, you can sort out many of the bad offenders. Bear in mind we are talking small signal tubes with that unit including 6SN7s with his socket saver/adapter. There are of course more sophisticated instruments of measure regarding microphonics.....just depends on what you are willing to invest. If you here crackling, rumbling etc. through the loudspeakers (speaker sensitivity plays a role here) then you may want to purchase a known low microphonic set of tubes to use a reference from a reputable dealer.....just a thought.
There are naturally microphonic tubes and there are damaged tubes which can be microphonic. Many small DHTs are microphonic, but that's different from a faulty one. All I can say is that a faulty one sounds different and is more microphonic, rather vague I'm afraid. Faulty microphonic tubes are useful for testing filament supplies, but not much else.
This post is made possible by the generous support of people like you and our sponsors: