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Pre-amp tubes for Aguilar DB 680

Discussion in 'Amps and Cabs [BG]' started by ivanthetrble, Dec 6, 2003.

  1. ivanthetrble


    Sep 9, 2002
    OK, so I acquired a used Aguilar DB 680 pre-amp and I would like to replace the tubes (since I don't know how old they are). Suggestions? Is there that much difference in the tone of different pre-amp tubes? Some favorties brands and how would you describe the tone. Looking for a clean of a tube tone as possible. Not looking for grinding distortion. Amp will be Stewart World 2.1 with Bergantino HT322 cab, Lakland 55-94 bass. Thank all ya toob heads in advance.
  2. Lockout


    Dec 24, 2002
    Just to make sure you're aware of this...

    Preamp tubes do not need to replaced after a certain period of time, they should last throughout the lifetime of the amp. You should only consider replacing the tubes if either:

    a) You don't like the tone you're getting with the tubes


    b) One or more of the tubes is broken/microphonic

    If you're sure that your situation fits into one of these categories, then you can think about switching out the tubes. However, I'm not familiar many different tube brands and how they sound, so I'll let someone else come along and help you there. :)
  3. ivanthetrble


    Sep 9, 2002
    Humm, that is a bit different than what the folks at BassNW told me. Sure, they should last a long time but I would think that any tube would fade a bit with time.
  4. Ever worry about replacing the transistors and capacitors in any of your equipment? They all wear out eventually as well and just so happen to have equivalent service lives to preamp tubes. IOW, if it sounds fine now, it should continue to do so for the next 50 years WITHOUT tube replacement.
  5. Jim Dombrowski

    Jim Dombrowski Supporting Member

    Jan 16, 2002
    Colorado Springs, CO
    I decided to experiment with changing tubes in my DB680 when I bought it (used) and wrote to Aguilar asking for comments or recommendations. If I remeber correclty, I was told that the only tubes that will have any real affect on the tone are the first and last 12AU7 tubes. I tried a couple variations. With some tubes, there was not a significant difference. I ended up using a pair of vintage 5751 triple-mica tubes, and it sounds a bit smoother to me.

  6. Any USA NOS should be fine, if you have money to burn try: Mullard, Telefunken, or Amperex Bugle Boy(Holland). Black Plate Triple Mica (RCA)5751's an not bad either.
  7. This quote from one of the other DB680 threads is prolly worth mentioning...

  8. ivanthetrble


    Sep 9, 2002
    Per the Mesa Boogie website:

    "Power Tubes will generally last 1 - 1.5 years.
    Preamp Tubes will generally last 2 - 3 years."
  9. Lockout


    Dec 24, 2002
    Those statements are simply not true. As Psycho Bass Guy said, preamp tubes should last just as long as the transistors and capacitors in your amp, as long as the amp is cared for. :)

    Power tubes on the other hand may need to be replaced occasionally in certain cases, but not necessarily. I know of people who still have the original tubes in their vintage SVTs, which is an extremely long time for power tubes to last.
  10. vanselus

    vanselus Supporting Member

    Sep 20, 2000
    Boulder, CO

    Mesa sells tubes. Why wouldn't they say this?

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