Tube Microphonics

HBombToo
HBombToo Posts: 5,256
edited October 2003 in Electronics
I do believe I understand this phenomena. I hear it on an SACD that contains 1 of my most favorite artists, Stevey Ray trck 12. Sounds amazing but I can hear it. I don't have the same redbook cd for a comparison but if I did... my perception could start another hall of shame entry:D

in my understanding microphonics(mp from here going forward) is feedback between the grid and cathode started by sound pressure.

Twin:D

i just turned on the keep alive:rolleyes:

i guess i should have done another 70/150 post:confused:
***WAREMTAE***
Post edited by HBombToo on
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  • organ
    organ Posts: 4,969
    edited October 2003
    I still can't hear it with my tubes but I'm sure it's there. All tubes are microphonic. What does it sound like on your system? If it's bothering you, there are a lot of tube dampening devices out there. Russman bought some for his pre amp tubes.

    Maurice
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  • organ
    organ Posts: 4,969
    edited October 2003
    Forgot to ask...Are you using a tube pre or amp? It's not listed on your signature. What brand/model#?

    Maurice
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  • HBombToo
    HBombToo Posts: 5,256
    edited October 2003
    I can start it at will by tapping the 6dj8's in my Audible Illusions Modulus. I hear it loud and clear over an sacd played on my solid state HT. Stevey Ray Vaughn track 12. or something like that.

    Twin
    ***WAREMTAE***
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  • organ
    organ Posts: 4,969
    edited October 2003
    How long have you had the 6DJ8's for? They've probably gone bad or are on their way out. Tubes become very mp when going bad. When my JJ pre amp tube went bad it became very mp and a light tap was clearly audible throuh the speakers. I tried tapping on my pre amp and power tubes and didn't hear anything. You might want to try a new set of tubes. Very nice amp btw.

    Maurice
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  • HBombToo
    HBombToo Posts: 5,256
    edited October 2003
    Originally posted by organ


    1.)Tubes become very mp when going bad.

    2.)Very nice amp btw.

    Maurice

    a gas leak is the killer.

    Thank you but the jury is out while i'm in repair mode
    Twin
    ***WAREMTAE***
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  • madmax
    madmax Posts: 12,434
    edited October 2003
    I can hear some microphonics when I tap on any of my tubes. Lets see, that would be about 49 tubes. I don't think they are going bad. A lot of it probably depends on the other associated electronics. Many use vibrapods or similar under their tube amps and preamps to keep floor/stand vibrations away. If the sound level is high enough for air borne vibrations you can use brass rings on the top of each tube. I forget who sells them.
    madmax
    Vinyl, the final frontier...

    Avantgarde horns, 300b tubes, thats the kinda crap I want... :D
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  • organ
    organ Posts: 4,969
    edited October 2003
    OK, I just check all my tubes again....The only ones that are mp is the pair of 7199 driver tubes on the Dyna. I still had to tap them pretty hard with my finger nail to hear anything from the speakers and it was barely audible. No mp on the other tubes though.

    Maurice
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