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Groove Tubes Studio Series Bass Tube Preamp

Discussion in 'Amps and Cabs [BG]' started by Blue, Apr 1, 2005.


  1. Blue

    Blue Supporting Member

    Jun 19, 2004
    Central NC
    I have a mid 80's (?) Groove Tubes Studio Series Bass tube Preamp - and I need a schematic. Anybody have one?

    Thanks in Advance
     
  2. Blue

    Blue Supporting Member

    Jun 19, 2004
    Central NC
    afaik, it is very similar to the SWR SM-400 Bass Amplifier Head, except it has no power amp.
     
  3. Blue

    Blue Supporting Member

    Jun 19, 2004
    Central NC
    .... and I'd be interested in "Sound Comparisons" from anyony that has had these ....

    Groove Tubes Studio Series Bass Tube Preamp
    A.M.P. BH-440
    SWR SM-400 Bass Amplifier Head
    Thunderfunk
     
  4. IvanMike

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

    Nov 10, 2002
    Middletown CT, USA
    best bet is to ask groove tubes or swr for a schematic..........

    the gt preamp is identical to the preamp section of the studio 220 and sm 400 (the original models). IME you wont find a single difference in sound.

    from what i've heard the amp and thunderfunk sound pretty darned identical, (although rumor is the tf sounds a little better) the closest thing there is to a soundclip comparison like you're looking for is on www.basstasters.com

    for swr i would check out the clips of the electric blue and grand prix (IME, all original SWR preamps including the GT one sound identical). then you can check out the thunderfunk clips.

    i've only been able to compare the original amp to swr. IME, the amp was warmer sounding (although not as warm as an eden) and had a much more "plug and play" sound than an swr.

    FWIW, i dig swr, amp and eden.
     
  5. IvanMike

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

    Nov 10, 2002
    Middletown CT, USA
  6. Blue

    Blue Supporting Member

    Jun 19, 2004
    Central NC
    I was able to get a copy of the SM-400 schematic, signed by Rabe in 1989, but GT said it "no longer had" the schematic of their version.

    I confess to being Eden Stupid - have never played one, but I have an original AMP-420 and a Thunderfunk; the AMP is clearly "thicker" than the Thunderfunk. Ask me in a couple week and I'll compare it to the GT.
     
  7. synaesthesia

    synaesthesia

    Apr 13, 2004
    UK
    Hey Blue

    The schematic is the same as the SWR 220 and if you ask SWR they will send you one. I have a copy somewhere on Jpeg if you care to email me.

    I had one and modified all the (8) TL072 chips with NE5532 chips, which are lower noise and it does make a difference;virtually no idle noise/hiss. The difference is sort of like a tape with Dolby on, probably 8 - 10 dB drop in noise floor. BTW, you can do this mod with most SWRs.