changing the tube in a Hartke 3500 head (how do I do it?)

Discussion in 'Amps and Cabs [BG]' started by facet squared, Jul 22, 2001.

  1. I've heard that the tube in the preamp of the Hartke 3500 is prone to noise and pops, and I think this is happening with mine. anybody know how to get to the tube to change it? should I just take it somewhere to have it done? if anybody has done this themselves please anwser back as you are exactly who I want to hear from...but anybody else is welcome to reply.

    any tube recommendations are welcome too. If possible please descrie the sound of the tube. Keep in mind that I do not have much money so $60 12ax7's are out of the question. I would like to be able to get a slight amount of overdrive out of the tube, but I realize that with the way the Hartke works this may actually not be possible.

    I know I ask a lot, so I appreciate all responses. thanks.
  2. and how often should you change the tube?
  3. Firstly make sure the amp is unplugged (and maybe been off for some time)
    Unscrew all the small screws from the top plate cover and lift off. You will see the tube on the left.
    Just gently pull it out and put the new one in taking care to line up the 9 pins. Fairly easy because there in a gap.

    I had my pre-amp tube in my 3500 for over 8 years. Replaced it with a Mesa Boogie 12AX7 (ECC 83) that I had spare from a 400+, and noticed no change in my sound. Put the original straight back and it is still fine another year later. This amp has been heavily gigged without any problems for nine years.

    Unlike power tubes, these pre-amp tubes don’t need changing unless you have a problem.

    Had the orig pre-amp tubes in a Fender Bandmaster for over 25 years.

  4. And ofcourse.. wear rubber gloves !
    the grease on your fingers will burn on the tube ( just like halogene lamps ) and will decrease the tube's life-span
  5. I.'.I.'.Nakoa

    I.'.I.'.Nakoa Guest

    Aug 10, 2000
    Fort Worth.
    i was about to ask the same question, . but on my hartke, sometimes, when i turn it on, i real low volume, no matter how high i turn it up. then i turn the tube pre amp knob to 0 and the solid state up. and it kicks in, then i turn that off, an turn the tube back up. anyone know whats wrong?