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tube pre amp question

Discussion in 'Amps and Cabs [BG]' started by dadodetres, Jul 11, 2005.


  1. dadodetres

    dadodetres

    Dec 19, 2004
    URUGUAY
    hi! i have a SWR grand prix and was wondering if the gain is before or after the tube...

    so if the gain if after: sending a hot signal can cause tube drive, but being before its the same, cause i control it woth the knob....


    also: can i damage the pre or the tube by doing this?


    and other question: if i put the pre amp on several hours before, will the tube be hotter so it can give me a warmer sound?
     
  2. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    methinks the "gain" you're talking about is within the tube itself. 12ax7 tubes (and many other preamp tubes) have 2 gain stages within them, which can be used at different points within the circuit. "Gain" pretty much occurs within amplifying components, such as tubes and transistors.

    and as far as i know, no. you wont get a different sound out of a preamp tube by warming it up. IIRC, they tend to stay pretty much the same temp after a minute or less.
     
  3. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    No. You can get warmer by using a different tube through... Many Tube pre's and I would expect the Grand Prix to be one, will sound better with a better quality tube. I'm not sure what the flavor of the day is in 12ax7 tubes, especially in your Pre. You might want to ask that in a separate post.