Harmony Central Forums
Announcement Announcement Module
Collapse
No announcement yet.

12ax7 lights up like a light bulb?

Page Title Module
Move Remove Collapse







X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • 12ax7 lights up like a light bulb?

    I have some RFT 12ax7 preamp tubes in my Chimera. When I turn the amp on, one of them always flashes really bright for a split second then fades to normal. It sounds good and is not micro-phonic. Has anyone ever seen this? I'm afraid it will mean a short lifespan.
    <div class="signaturecontainer">Rivera K-Tre <br />
    Randall T2 <br />
    <br />
    Carvin, Gibson, ESP<br />
    <br />
    Good deals with: Shredtilurded, Juggernaut, Guillatool1( x2 ), MatrixClaw, CRANK,Clonexx, Chris the Asian, Slav123, lfrz93, ldonnell89, Khoifish321, bankboy, JJPSGAK, DTorg, jdr94, Yo_Squig, coolblues309, samthinguy, MorgMetal666, Uberthrall, Duke318, Harris, Katana, mctallica1, JerEvil, GuidanceofSin, phreddy, O'Rourke, Toshiro, the4thlast1, aywilson, shask, NeoAngelo, TomCray, scottcrud,sdgails, GibsonVMan, 100 watt</div>

  • #2
    I had one that did that, but it only did in the PI position. So i switched it out for another one that didnt -though they were both chinese 9th gens.

    Apparently some tubes just do that inherently.
    <div class="signaturecontainer">Missionary ov <b>t<font size="3">e</font><font size="4">h </font><font size="5">b</font><font size="6">o</font><font size="7">os</font><font size="6">t</font><font size="5">e</font><font size="4">d </font><font size="3">m</font>idz</b><br />
    I like to build things <img src="http://img3.harmony-central.com/acapella/ubb/smile.gif" border="0" alt="" title="Smilie" class="inlineimg" /><br />
    <font size="1">Good people: TomVanDeven, I.P. Freeley, Science!</font></div>

    Comment


    • #3
      A couple old RCA's i have in my splawn do that. They sound great so I dont worry about it.
      <div class="signaturecontainer"><font size="1"><font color="Navy"><br />
      '12 Carvin DC800 <img src="http://img3.harmony-central.com/acapella/ubb/love.gif" border="0" alt="" title="love" class="inlineimg" /><br />
      '08 Loomis FR EMG 707's<br />
      </font>---<br />
      <font color="Green">Splawn Quickrod EL34's (Purple)<br />
      AxeFX Ultra<br />
      ART SLA-2<br />
      </font><br />
      <a href="http://www.youtube.com/aconstantbattle" target="_blank">http://www.youtube.com/aconstantbattle</a><br />
      </font>---<br />
      <img src="http://img3.harmony-central.com/acapella/ubb/love.gif" border="0" alt="" title="love" class="inlineimg" /> Super Sexy Splawn Society <img src="http://img3.harmony-central.com/acapella/ubb/love.gif" border="0" alt="" title="love" class="inlineimg" /></div>

      Comment


      • #4
        Some tubes do this. I think it is some current limiter thing built inside them.

        Comment


        • #5
          Dunno about a current limiter, but my NOS valves seem to do it more than current production.
          It can be pretty scary seeing a
          <div class="signaturecontainer"><a href="http://www.youtube.com/paolojm" target="_blank">www.youtube.com/paolojm</a></div>

          Comment


          • #6
            I have some too. Don't know why they do that. Sounds good so no worry... i call it "prewarm-up".

            Comment


            • #7
              I have a 6L6 in a Herbert that does that. Only after the amp has been off for a awhile though.
              <div class="signaturecontainer"><div align="center"><font face="Garamond"><font size="2"><b><img src="http://img3.harmony-central.com/acapella/ubb/Totally_jammin_out.gif" border="0" alt="" title="Jammin'" class="inlineimg" /> Gibson|PRS|Mesa Boogie <img src="http://img3.harmony-central.com/acapella/ubb/Totally_jammin_out.gif" border="0" alt="" title="Jammin'" class="inlineimg" /></b></font></font><br />
              <a href="http://www.rig-talk.com/forum/viewtopic.php?f=19&amp;t=67094&amp;p=769514#p76951 4" target="_blank"><font face="Garamond"><font size="2">100+ Good Deals/Transactions between Harmony Central, Rig-Talk, and The Gear Page</font></font></a></div></div>

              Comment


              • #8
                I have a bunch of Mullards that do that. It's normal.
                <div class="signaturecontainer"><div align="center"><font face="Century Gothic"><font size="3"><font color="black"><i>Vintage</i> V100 ICON <font color="black">&quot;Lemon Drop&quot; </font></font></font></font></div><div align="center"><font face="Century Gothic"><font size="3">Fender American Standard Stratocaster</font></font></div><div align="center"><font face="Century Gothic"><font size="3">Seagull Entourage Rustic S6</font></font></div><div align="center"><font size="3"><font color="black"><font face="Century Gothic">Traynor</font><font face="Century Gothic"> Custom Special 50</font><i><font face="Palatino Linotype"><font face="Century Gothic"> (YCS50)</font></font></i></font></font></div><div align="center"><i><font size="3"><font color="black"><font face="Palatino Linotype"><font face="Century Gothic">Traynor YGM-4</font></font></font></font></i></div><br />
                <br />
                <div align="center"><font size="1"><font face="Book Antiqua"><font face="Garamond">Good transaction with: NickPierro</font></font></font></div></div>

                Comment


                • #9
                  All my Amperex, Mullard, and Siemens 12AX7s do that.

                  Can't remember if my Mullard CV4024 do as well
                  <div class="signaturecontainer"><b><font size="1">AMPS</font></b><font size="1"><br />
                  <font color="Blue"><b>Peters Hydra<br />
                  Peters Chimera </b></font><br />
                  Peavey 5150 -FJA Modified-<br />
                  Peavey VTM120</font><br />
                  <font size="1"><b>CABS</b><br />
                  <font color="Blue"><b>2-Mills Acoustics Afterburner 412A</b></font>(G12K-100XHellatone 60L)<br />
                  2-Peavey 5150 Cabs(G12T-100)<br />
                  Peavey 5150 Cab (WGS Veteran 30)</font><br />
                  <b><font size="1">GUITARS<br />
                  <font color="Blue">ESP Horizon NT-II (Neck:Painkiller/Bridge:Painkiller) </font></font></b><font size="1"><br />
                  Gibson Les Paul Studio (Neck: D-Activator/Bridge: D-Activator)<br />
                  Ltd EC-1000 (Neck:Evolution/Bridge:EVO2)</font><br />
                  <font size="1"><font color="Blue">Great Transactions w/:sdresdre,lumpy555,angelhair0,boleiro,Dark Aegis, ErikHoppy,hemiram2006,Rhammer19,mincy</font></font></div>

                  Comment


                  • #10
                    RFT 12AX7 do this. It's not isolated to the Chimera, that's for sure.

                    Also from my FAQ:

                    "Some preamp tubes also glow brightly briefly on power-up; this can be normal and not a sign of a bad preamp tube."

                    I have some Chinese 12AX7B which do this too.
                    <div class="signaturecontainer"><b><a href="http://www.petersamplification.com" target="_blank">http://www.petersamplification.com</a></b></div>

                    Comment


                    • #11


                      Like that? The video says it's a leaky tube with gas in it.
                      <div class="signaturecontainer"><a href="http://www.myspace.com/stopbreathing45" target="_blank"><font size="4">My band: STOP BREATHING</font></a></div>

                      Comment


                      • #12
                        Sounds like it's time to turn out the lights and invite some girls over

                        Comment

                        Working...
                        X