Slave Amp or Power Amp ???

Discussion in 'Amps and Cabs [BG]' started by Oren Hudson, Aug 8, 2008.

  1. Oren Hudson

    Oren Hudson

    Dec 25, 2007
    Gastonia, NC
    So what's the difference between a slave amp and a power amp? :confused: Particularly interested in using a power amp rather than a slave amp to add watts to the existing amp on a bass rig. Is this possible and/or a good thing? If so, how would I hook the 2 together? :cool:
  2. Jazzman


    Nov 26, 2002
    Raleigh, NC
    They are the same thing. A power amp is more of a general term, and a slave amp is one application of a power amp.
  3. spode master

    spode master

    Jan 21, 2007
    Normally when you see bass players with multiples of the same rig with the Same head on stage.

    The bass player uses only one of the head as the Pre-amp/Tone Control, then Daisy chains the Line out of the amp to the amp in of another.

    The first Head that the bass is plugged into is normally considered the Master, the rest are Slave amps, the signal and levels are all determined my the Master amp pre's.

  4. ErnieD


    Nov 25, 2004
    I think I asked the same sorta question on a Carvin amp thread today, no replies yet. But I wanted to buy a Carvin DCM1500 power amp or similar amp, to hook it up to my GBE750 amp head. I play this huge room about twice a month, no PA support, loud gitard and I wanted to run a Carvin amp thru my head to get about 1500 watts bridged at 4 ohms.

    My amp works fine for all my other gigs but this huge room takes all I can give my GB amp, the clip lite just stays lit too much for me to feel safe, no distortion but I think that's next. Ive taken as much lows out as I can, added mids and highs more than I ever do. So I too would like to know how I could hookup a, prolly Carvin, power amp to my GBE750 head.

    What inputs/outputs would I use? what type and how many cables do I need? And mostly is this even do-able? I think we're on the same topic here. Anybody?
  5. bongomania

    bongomania Gold Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    Your amp head should have a jack that says "preamp out" or "line out". Run that output to the input on the power amp. Easy-peasy, only one extra cable needed. Oh yeah, unless you are using a combo amp, in which case you'll need an external speaker cab that can handle the extra wattage, and a cable for that to connect to the power amp. For the connection out of the preamp into the power amp, double check the manuals for both devices to see whether you need a balanced (TRS) or unbalanced (TS) cable.
  6. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    If you don't have speakers that can make use of the extra power it will make little, if any, difference. OTOH adding a second identical speaker with your existing amp will give an additional 6dB output, the equivalent of four times the power you now have.
  7. ErnieD


    Nov 25, 2004
    Yeah I usually use 2 cabs at big rooms, NV215 + GB Neox 212T w/GBE750 both 4 ohms, amp can do 2 ohms. It's quite loud for that big room but I do see the clip lite way too much for my eyes, no distort, just too much clip on too many notes.

    And I know how we all feel about this but NO PA for bass with this band. Only 2 15" Carvin PA cabs on stands, 3 vox & kick drum in PA only. Loud@zz gui****, loud but very good vocalist and many Harley's coming/going all thru our gig, front garage type doors wide open, just a big, loud place.

    I even emailed Jim @ Bergantino asking him which other of his cabs would match up well with my NV215 and he implied that a more powerful amp would open up the NV215 cab. Dont really want to buy/use another amp head. So I figured, though being very careful with volume and low knobs, to add a power amp thru my GBE750 and try the NV215 alone, bridged @ 4 ohms aprox 1500 watts with that Carvin amp. I'd also have the 2nd cab 212T, handy if the NV gets to working too hard, so I guess my new power amp needs to do 2 ohms or a good +600 watts into each channel at 4 ohms.

    Been wanting to use NV stand alone at some big gigs and Im getting real close to talking band into running just a little bass thru the mains, may just happen. So without adding a 3rd cab or having to buy a 2nd larger cab, will the external power amp work for me with the NV cab? Its rated 600 watts so I'd be careful with the possible bridged 1200+ watts or so into it. Just trying things out to get good, clean and loud. :bassist:
  8. ErnieD


    Nov 25, 2004
    will hookingup a external power amp then bypass a amp heads' internal amp, thereby only sending the external amps' power into any cabs? Correct?
  9. Jeff A

    Jeff A

    Oct 22, 2005
    Run GBE750 into GB Neox 212T and use DCM1500 (as slave amp) bridged into NV215.
  10. BetterBottomEnd

    BetterBottomEnd <- Not me I just like looking at her

    Jan 9, 2007
    Cable Wi
    The main amp's power section will still be running. You could plug a cab into that as well as the power amp. As long as it's a solid state power section though theres no real need to plug anything into it though.
  11. TGH Bass

    TGH Bass

    Feb 8, 2008
    Toronto, ON
    One thing that I haven't seen in this thread is this...

    No amp can output more power than it's stated value. When you use an amp as a slave, it doesn't suddenly go from it's stated power output to that output plus the stated output of the master amp.

    Therefore, each amp you're using must have speakers hooked up to it to get a total output of the combined amps power.

    For large halls I use my SVT-2 Pro with my Stewart 1.2 as a slave. Each amp has 2 Markbass 410 cabinets hooked up to it. The SVT pre-amps the Stewart and therefore controls the "tone" of all my cabinets. I can use the output masters on the Stewart to control the volume of the cabs hooked up to it. Total watts for this set up is around 1500 watts. Shockingly clean enough to require the "drive" on my SVT to be pushed a bit. No clipping!
  12. AA bassist

    AA bassist

    Jun 17, 2010
    i need more help i have a GK1001rb 2x10 i run with a 15 ext cab, i want to run another 15 cab i own with another head as a slave is this possible so in all 3 cabs and two bass heads
  13. dincz


    Sep 25, 2010
    Czech Republic
    Now I'm really confused! You don't know the difference but you want to use one rather than the other?
  14. AA bassist

    AA bassist

    Jun 17, 2010
    i wasw wondering if it was possiblr to run all 3 cabs and both of my amps together is al
  15. Bassdirty


    Jul 23, 2010
    The answer is:
    It depends.
    You didn't give the specs of the 2nd amp head, or the speaker cabinets.

    Most likely there is a way, but we need the specs.;)
  16. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    In my mind a slave amp is a power amp Identical in looks to a master head using the same output stage as the master but with only a volume control. The idea was to drive cabinets with each but only need to mess with the controls of the master to affect them all. In practice the slave would cost virtually the same to make as the master and players thought it looked cooler to have identical amps. Slave amps are quite rare.

    A power amp is usually stereo and SS although some tube ones do exist.
  17. So I could use my SVT CL as the tone master and slave out my Hartke 3500 for 650 watts total as long as I had a 4 ohm load still connected to my SVT in theory? So if I only wanted to use one cab rated at 700 watts and it needed to be the one plugged into the SVT because of the load necessity would I run the "slave" out from the SVT into the main input of the Hartke; then from the Hartke effect loop "send" back into the SVT "power amp in"? This also depending on whether the Hartke doesn't need a speaker load.
  18. you would leave the Hartke in the van unless you were running lots of cabs. Then you would take line out of SVT to power amp in of Hartke.
    S-Bigbottom likes this.
  19. I must have misunderstood the Master/Slave amping concept. I knew one purpose was for running a lot of cabs with the same amp tone but I also thought it would allow you to have more watts going into a single cab if desired?
  20. yes, you are coming to the realisation that you thought wrong.

    One amp channel per cab.

    Minimum impedance per SS amp channel.

    At least one cab per tube amp channel.