Microphonic from Vacuum Tubes?
HI, I have a question regarding microphonic from vacuum tube. I have a Cary SLP-05, and I've changed the output gain tubes to some NOS RCA, and also recently purchased a pair of Linlai for the balanced buffer stage.
I now occasionally hear a loud pop in the music. It doesn't happen very often, but when it does, it is quite loud. This happens when I am streaming digital music, so it can't be those occasional pops you hear from vinyl.
Can someone tell me if this loud pop possibly caused by microphonic in my tubes? if so, how do I track down which tubes? My guess there is no easy way but change one tube at a a time, which can be extremely time consuming. Also I don't own a tube tester. I wonder that would help tracking it down.
Also I read something about vacuum tube damper rings, would that help calming down possible microphonic?
I still consider myself a newbie in tubes, so any hep will be appreciated. Thanks very much.
@xcool Really! That is telling you something. In that case play the LPs only for a week. If you don't hear any pops, I'd look into issues with your digital setup- as @acman3 points out, digital is quite capable of making loud pops!
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When you make a change and things go south its a good bet that the problem is associated with something you did. However, that bet can also blind you to what is really going on; pursuit of the problem in that manner can yield no results if its not really the issue. Equipment turning on or off can create pops that come into the equipment on the AC line. IME, most so-called high end audio 'conditioners' are not really all that good at their job and may be unable to filter such events, or they could even cause them. Some preamps are more susceptible to this sort of thing so it is possible that the Cary is working fine but simply can't reject events like this. I see this hypothesis as unlikely since we'd have heard of it before on this forum... And of course the popping could be a failing power tube that is arcing. So it is worthwhile to do your due diligence. |
@xcool Like I said, don't make any assumptions. Right now it sounds like you need to sort out for real which channel its in or if its in both. If its randomly in both, FWIW I'd be more suspicious of your source... but keep an open mind. That's the first rule of troubleshooting. The second is not to make assumptions. |
@xcool OK- keep in mind to make no assumptions. That can lead you on a wild goose chase. The first thing to do is swap the interconnect cables left for right at the amplifier inputs and see if the problem moves. If yes => the cable, preamp or source is on the hook If no => the amplifier is the problem. So do that and get back to us. Or, if the problem moved, the next thing to do is swap the connections from the source at the input of the preamp. If the problem moves its the source or its interconnect cable. If the problem stays put then the preamp is on the hook. If you get to that point then you swap tubes from one channel to the other, a pair of tubes at a time. Between each swap you play the system until you can determine which channel has the bug. If it moved you know which tube is bad, if it didn't then you proceed to the next pair of tubes and repeat the process - do this until the problem moves and then you've located the bad tube. Good Luck! |
It isn't. Microphonics isn't a popping sound, its the tube being able to vibrate in such a way that it can generate a tone; in some cases I've seen it be so bad you could yell at the tube and be heard in the speakers. What you are describing is something else. Tubes can make crackling and popping sounds which aren't microphonics and have nothing to do with that. But if we're talking about a tube, @larryi has some questions that really have to be answered to get anywhere. If in both channels and it were a tube, that tube would have to serve both channels which seems unlikely. Does this sound occur if the volume is all the way down? How do you know its in the preamp? |
