Need help with new amp

Discussion in 'Amps and Cabs [BG]' started by Wadge, Oct 31, 2003.

  1. Hi all, I have a question:

    I have a Trace Elliot, 2X15 Cabinet, 4ohms. This is powered by a GK 400RB Amp. After having bought the amp I discovered that is can only power a single 4 ohm Cabinet or two 8 ohm cabinets.

    I would like to add a 4X10 cabinet in the future to the 2X15.

    The questions are: 1) Must I get another 4 ohm cab or can I get an 8 ohm cabinet to go with the Trace Elliot 2) I also have an SVT-3PRo preamp - is there a power amp which I could use to have mulitple cabinets.

    Your help would be greatly appretiated (I've been playing bass for 13 years but I know next to nothing about electronics and the physics of it all.) Thanks in advance
  2. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member

    Err ...that's why it's best to check these things out before buying!!

    You have two options - trade in the cab or trade in the amp for something that does what you want!
  3. The GK400rb is only about 200/250 watts into 4 Ohms if I remember right. That should sound reasonably loud through your 2x15 4 ohm cab.
    If you wanted to add a 4 x 10 to that rig I think the amp would be pretty underpowered, not to mention the impedance miss-match problem presented by the Trace Elliot being 4 Ohms.
    ie, 2 x 4 ohm cabs would present a 2 ohm load to the amp, and GK do not recommend driving their amps at 2 ohms. I'm not sure what the impedance would work out at if you used an 8 ohm cab with the 4 ohm one, but the amp might not like it and the boxes would probably have very different output levels.

    An option would be to use your Ampeg pre into a stereo power amp and drive the miss matched speaker cabs in stereo. You could control any volume differences of the seperate cabs with the power amps main output controls. If you did decide to go this route you could even buy another 4 ohm cab rather than 8 ohm which would then give you an even out put from both cabs and would also allow you to bridge the power amp channels for even more power if you need it.

    Thats my opinion, get a few more before you make any decisions.
  4. Scott D

    Scott D

    Apr 21, 2003
    Minneapolis, MN
    Uh, the Ampeg SVT-3 Pro is a head, not a Preamp...

    You could be thinking of the SVP-Pro, or the SVP-BSP, Or possibly a B1 (actually a 150W head, but alot of people use them as preamps)
  5. I took it that he meant the SVP Pro pre-amp, otherwise I don't see why he would be asking after power amps.