Advantage of using a power amp?

Discussion in 'Amps and Cabs [BG]' started by creis2, Dec 5, 2012.

  1. creis2


    Nov 11, 2011
    Cambridge, MA
    I have two 4 ohm cabs I've been meaning to run together for a while. My Ashdown head doesn't go below 4 ohms, like most heads.

    I was considering a power amp. But even the lightweight ones take up a bit of space. I don't run racks, so by the time I add a 2u rack, I'm lugging a lot of stuff around just for two small cabs.

    Also, a good power amp can cost just as much as a decent micro head. The Carvin I was looking at was around $500, where around the same price, I can pick up a super lightweight GK micro head.

    Is there a difference between running my ashdown head into a 2 channel power amp into my two cabs or running my head with one output into one cab , preamp out into power amp in of a microhead, into the second cab?

    I would much prefer the microhead option. Saved weight and also I have a backup with me if one head goes down.
  2. The bx500 goes down to 2ohms i believe
  3. creis2


    Nov 11, 2011
    Cambridge, MA
    I guess I should have mentioned, I would prefer to have individual control over each power section. Also, I want my Ashdown to be the preamp either way I go.

  4. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    You can get a new Crown XLS1000 for around $250. Still rack size, but only 11 pounds. The XLS1500 is around $325. Also 11 pounds. They go to 2 ohms bridged, but you could run one 4-ohm cab off each side and individually control the power going to each one.
  5. Josh Thatguy

    Josh Thatguy Registered abUser

    Advantage of a power amp: WATTS. I compete for sonic attention with a guitarist using two Marshall tubehead fullstacks, so two bridged QSC 1450 power amps through a BBE rack preamp is good for my 'fridges.
    As per your "difference" question, YES, there's a difference between using your Ashdown as a preamp/tone control into a power amp with both your cabs versus running your Ashdown into one cab by itself, then using another head with the pre-in/power-out for the other. Chances are you're going to "flavor" the tone and loudness of the second cab to an unequal degree, if anything just because of the chain of wattage and inherent colorization on cab #2 running source/cable/preamp/cable/power source/cable/cabinet, and personally I think the on-the-fly complications trying to match the volume with each cab would be a pain. And this assumes your head would *let* you use one speaker-out AND the preamp out to another source; some amps do one or the other but not both.

    Also, "most" of the bass heads I've seen don't go to 2ohm, most go to 4ohm. A 2ohm head is a rare bird, but is typically a nice high-end tube head. Power amps can typically run 2ohm without question, though often the power figures advertised are 4ohm OR 4ohm bridged.

    Personally, I say a power amp/preamp in a rack package is ideal, but that's after playing since 1995 and getting tired of searching for more power in a package I can seal up in a case and stick in the trunk of a car or in the luggage bay of a tourbus, but throw on top of an 810 no matter what size venue or backline of other bands sharing a night on stage.

    POST SCRIPT: by the time I answered the phone then typed my reply, you'd already clarified you WANT individual volume control for each cab, so that sort of negates my "it's be a pain" explanation. I'm assuming they are different brand cabs or different speakers sizes..... whereas at first I was assuming they were two identical 410s or something. Ooops
  6. creis2


    Nov 11, 2011
    Cambridge, MA
    Thanks for the explanation. They're the same brand cabs, same speakers, but one's a 410 and one's a 210. No need for anyone to go into mixing speakers, and all of that stuff, I'm aware of what I'm doing.

    My ashdown gives me more than enough power into my cabs, plus, I don't play super loud.

    The only thing that is pushing me towards the power amp is that you said "this assumes your head would *let* you use one speaker-out AND the preamp out to another source; some amps do one or the other but not both.". Didn't know this.

    I'm not at all trying to be cheap, just be practical. I like the idea of having a backup head if needed, plus I like to run light. I don't run a complex rig, I play a bass I like into a head I like into a cab I like, I try to avoid things getting in the way of that.
  7. creis2


    Nov 11, 2011
    Cambridge, MA
    I'm doing a lot of forum searching, and coming up with little bits and pieces of info.

    I guess what I'm trying to do is "Slaving", if I'm not mistaken.

    Looking to run my Ashdown preamp and power amp into cab one. Use the Ashdown preamp out to go into a microamp to power my second cab.

    A lot less weight, no need for a rack, and I have a backup head if my Ashdown goes down (which is common).

    A power amp is another step towards a rig that looks like an airplane cockpit.
  8. TheRealKong


    Mar 17, 2011
    There are some hybrid bassamps hat go down to 2 ohm. Lots of Peaveys do. So does my old T-Max.

    One of my rigs is an Ampeg SVP PPro with a Thoman poweramp, called t.amp TA 1400 MK-X. It is a real cheap one, about 300 USD. But it is a class A/B-amp, 21 kg heavy. But there is enough power! 2x 700 watt @ 4 Ohm, 2x 550 watt @ 8 Ohm. If I want to run only one cab, I simply use only one side of the poweramp.

    I have one Peavey TVX 410 in 4 Ohm and one Peavey TVX 210 in 4 Ohm. In case of a bigger stage I used to use both cabs, one per side of the poweramp. Today I often use the SVP Pro and only one side of the poweramp into my Tecamp 810 L. Or into my 212 SWR with Beyma replacement speakers, 600 watt @ 4 Ohm. It works beautiful!

    Btw, my GenzBenz GBE 1200 goes down to 2 Ohm as well.

    So long - sayes Kong.
  9. Slave away, just don't blow the 2x10.
  10. What's your backup preamp?
  11. creis2


    Nov 11, 2011
    Cambridge, MA
    There's a lot of cool 2 ohm capable heads out there, but my ashdown gives me a tone I'm more than happy with.
  12. creis2


    Nov 11, 2011
    Cambridge, MA
    Thanks. Is there an advantage of a 2 channel power amp over slaving?
  13. creis2


    Nov 11, 2011
    Cambridge, MA
    No backup head yet. All I have is the Ashdown. I just find it to be more practical to buy a microhead instead of a power amp. Looking at the GK microheads. Not interested in their preamp section all that much, I'm more than happy with the Ashdown's pre.
  14. It would pay to try one out but preamp out going to micro bass amp power amp in is a valid plan.
  15. creis2


    Nov 11, 2011
    Cambridge, MA
    I'm defiantly going shop and find a microhead that I like, but I can figure that out on my own. Just wondering if my ashdown + my future micro head is a solid option for two 4 ohm cabs.
  16. Some of the power amps have nice processing available to cut the low lows out for you, do a low pass to emulate vintage, as well as limit the power if you need to get max loud one day outdoors.
  17. But then you are reliant on your Ashdown preamp.
  18. oldcatfish


    Jan 8, 2011
    If you go the poweramp route, you could always pick up a VT bass, BDDI, Tonehammer, etc. pedal that will provide enough juice to run a poweramp. Just stick in your gigbag as a backup.

    Personally, I'd just slave into a microamp like you are planning. That way for low power gigs, you could just grab your 2x10 and the micro.
  19. johnpbass


    Feb 18, 2008
    Glen Mills, PA
    Good point oldcatfish.
    I get great results running my Tonehammer into a poweramp.
  20. creis2


    Nov 11, 2011
    Cambridge, MA
    I currently have a VT bass. But my biggest fear of a power amp is the added weight and space. If a microamp + my head can essentially do the same thing a a poweramp, it seems buying a microamp is a better idea.

    90% of my gigs won't need the 2nd cab. So having a micro head instead of a power amp seems a bit more practical.