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BBE Bmax-T Preamp tube? Help!

Discussion in 'Amps and Cabs [BG]' started by FroggyOne2, Nov 17, 2006.

  1. i am looking for opinions for a good preamp tube to use in my BBE BMax-T pre. It currently has a GrooveTube 12ax7 in it and I would like to change it, but not sure which direction I want to go with in a preamp tube.

  2. chris4001asat


    Dec 16, 2002
    Toledo, Ohio
    Warehouse Manager : Reverend Guitars
    I'm looking for opinions myself. I think mine crapped out last night. I got to the gig last night, and had virtually no signal going into my power amp. I had my active bass plugged into the passive jack, had the gain on 10, and still couldn't get enough signal to trigger the compressor. Not to mention I had to crank the bass, and it was still barely thumping.
  3. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    DFW, Texas
    I recommend the JAN-Philips 12AX7WA or Sylvania 7025 (basically the same tube).
    Good balanced and articulate tone for bass guitar.
    Find one used and tested or NOS.

    These tubes should last a very long time.
  4. chris4001asat


    Dec 16, 2002
    Toledo, Ohio
    Warehouse Manager : Reverend Guitars
    It was definitely the tube. My guitar player gave me a spare Electro-harmonix tube he had. Won't really know how it sounds till rehearsal wednesday night. He also told me the Groove Tube that was in it, are on the cheap end in the tube market.
  5. I replaced the stock tube with a Mullard from Lord Valve and it really opened up the overall tone. Better lows and clear highs (almost SWR like). Plus he suggested the 12au7 tube to reduce the amount of gain. That worked much better for my active basses.
    Mine did go microphonic on me after about 6 months, but the replacement I bought has lasted longer. It could have been from getting bounced around in the SUV. I usually put the rack on top of the speaker cab with a pc of foam between, and yeah, it does vibrate a lot when I crank it. :D
    Just my 2 cents. Good luck. :)

  6. This is what I was concerned about.. being the the signal from the Bongo is really hot! I will try the 12au7, now the question is.. which one to get!

  7. I suggest trying Lord Valve. I won't quote prices but his was very resonable, epecially for a Mullard. That particular tube evidently is not as popular as the 12ax7's and was lower in price, or he had a bunch of 'em. Either way it's a good deal.
    He's a trip to talk to and a real character.
    Good luck FroggyOne2. :D
  8. chris4001asat


    Dec 16, 2002
    Toledo, Ohio
    Warehouse Manager : Reverend Guitars
    Hey Shindig, did the 12au7 really lower the gain much? I've heard that you can send them in to BBE and they do a free a mod....but if it needs a new tube already, and that would do the trick, I'd rather just do that. I plug into the active input, and really can't turn the gain more than a 1/4 up.
  9. "Hey Shindig, did the 12au7 really lower the gain much?"

    It worked for me and my active basses (bart & demeter pre's).
    Like you, I could not turn the master much past a quarter. With the au7 I can go to half or a bit more.
    If I remember right, the mod to reduce the gain is a replacement of some resistors with different values. It should be available thru a search of this forum. I've probably got it somewhere in an email.
    I chose the tube swap because it didn't alter the stock circuitry and it changed the tone for the better at the same time :D . What's not to like? :smug:

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