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Compact/lightweight head for 2 Aguilar GS112s.

Discussion in 'Amps and Cabs [BG]' started by philthygeezer, Apr 19, 2005.

  1. philthygeezer


    May 22, 2002
    I would like to lighten the load on top. I actually have 3 GS112's so 2 ohm load handling would be a plus. I'm thinking I may not need more than 2 cabs anyway.

    What would you recommend?
  2. KJung

    KJung Supporting Member

    For 2ohm load, the only small heads I am aware of are the iAmp800 and the Acoustic Image Clarus. The AI clarus sounds WONDERFUL with acoustic instruments, but is a little tubby (IMO) for electric... especially if you are a roundwound type player.

    If you are comfortable with 2 cabs (4ohm) minimum... the Walter Woods is a wonderful (if expensive) head. I would recommend the Ultra (which is what I use). The Eden550 is also a wonderful small head, and for the money (along with the iAmp800) might be the best deal out there for small, powerful, reliable heads that sound good loud and soft and decent with both upright and electric. Hope that helps.

  3. KJung

    KJung Supporting Member

    I forgot about the Thunderfunk (and I own one!).... another great, small head at 4ohms minimum. I have mine in a rack and forgot how small it was as a stand alone head.
  4. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL
    EA iAMP-800

    i've safely run mine in 2 ohms w/ a pair of Epifani UL210's (4 ohms each), and the sound was MONSTROUS. also, the EQ lets you dial in plenty of punch and plenty high end for the aggie's somewhat darker nature.

  5. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    Maybe a class D poweramp with some lightweight preamp in a small rack... Other than that I think everything has been mentioned.
  6. tombowlus

    tombowlus If it sounds good, it is good Gold Supporting Member

    Apr 3, 2003
    Fremont, Ohio
    Editor-in-Chief, Bass Gear Magazine
    Ideally, for 2 ohm or 2.67 ohm load situations, my first choice is my iAMP 800 (which I do not find to be hissy ;)). But, with some cabs I have also had a lot of luck using my Walkabout with a 2 ohm or 2.67 ohm load. The manual says that it is stable to 2 ohm, but that the "preferred minimum load" is 4 ohm. Either way, mine has never had a problem running a 2 ohm load. But, the iAMP 800 will push three or four GS112's with ease, and it has a lot of headroom and very tight lows.

  7. I second the Thunderfunk and according to Dave Funk the T-Funk will do 2 ohms it just will not produce any more usable power....Chime in here Dave.....


  8. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL
    mine's cool. quiet as a church mouse. but dag, that musta been a real pain. if there's anything i cant stand, its hiss from my rig. :(
  9. the dude

    the dude Supporting Member

    Sep 19, 2004
    Dave told me the same thing. Just be sure to use 12 gauge speaker cables.

    Here's a list of 2 ohm capable heads. Looks like one other lightweight (other than the iAmp and Clarus) is the SWR 350.
  10. Thunderfunk


    Mar 27, 2004
    McHenry, IL
    O.K. Let’s say that I’m a manufacturer that makes a dinky little amp for cheap. Since it’s a dinky little amp I design a 2x10 enclosure to go with it. This keeps my costs down and I can sell a bunch of them. Since I want to get the most power out of that little amp, I design the enclosure to be 4 ohms. Everything’s going along great.

    Then some customer says, “I want to run two of those 2x10” cabs to equal a 4x10.” Now our plan is falling apart. The amp might run 2 ohms, but it’ll get hotter, and strain the output devices because they’re putting out more current. If you don’t play it too hard you might be fine. Or, the manufacturer can just design the 2x10 to run at 8-ohms, but then you’re complaining that when you're only running one cab, the amp doesn’t put out as much power. Nobody’s ever happy.

    Or you could just buy an AccuGroove with the AccuSwitch and set it for 4-ohms, or 8-ohms as need be.

    A lot of guys think an amp that can drive a 2-ohm load has more capability than an amp that can’t. Totally not true. If you think you’re getting free power by running at 2-ohms, then why not run the amp at 1-ohm? Or even better, zero-ohms and get an infinite amount of power? Or the guy that has a 4x10, and a 1x15, and he plugs them all in, only to find that the 15 drowns out the 4x10 and he’s fighting with the EQ to try and “fix” the “problem.”

    When a power amp’s designed there’s two basic questions. How much power, and at what load? The amount of power is set by the voltage the amp operates at and the intended load. If the amp can swing 40-volts into a 4-ohm load, you’ll have a 400-watt amp. In order to generate 40-volts into 4-ohms you‘ll need to deliver 10-amps of current. So now you have your design goal. Attach a 2-ohm load and what happens? 40 volts divided by 2 ohms = 20 amps of current. 20 amps times 40 volts equals 800-watts, right? Free power, right?? Wrong. The transformer can’t deliver 800-watts. It’s physically only big enough to deliver 400-watts. And the transistors are rated for 10-amps because that’s the design goal, and the transformer and the transistors overheat and the amp blows up.

    So, why not design the amp to deliver 400-watts at 2-ohms? O.K. Now the transformer only has to put out 28.3-volts into 2-ohms, but needs to deliver 14 amps of current. It’s still a 400-watt transformer, the voltage/current ratios are just different. And what do you do? You plug in your favorite 8-ohm speaker and it only puts out 100-watts, and you’re still not happy.

    Now add the problem of Beta droop that can happen when you operate an amp at 2-ohms, and the 8-gauge speaker wire you’re carrying around because otherwise you’re wasting power consumed by wire losses, and at certain frequencies the speaker impedance is dropping to 1-ohm or less, and even though the manufacturer said it’ll drive a 2-ohm load, you’re just waiting for disaster. All this so you can “optimize” your rig by using the speakers you already own. Can the Thunderfunk drive a 2-ohm load? Sure it can. Will I say it’s a good idea? No, I won’t.
  11. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL
    well, if there's one thing i cant stand, its hiss. hate it hate it hate it! hope i made myself clear. ;)

    but all the more reason i really dig my Acme cabs, which are very quiet, and who's tweeters are of the smooooooothest i've ever played thru.


    can you go into detail about the "Beta Droop (Drop)"?
  12. Thunderfunk


    Mar 27, 2004
    McHenry, IL
    All bipolar transistors exhibit a decrease in gain at higher currents, causing a type of distortion referred to as beta droop. It is difficult enough to maintain good linearity with 8- and 4-ohm loads, especially in light of the radically variant reactive characteristics of loudspeakers and crossover networks. Doubling the already shaky current problems of 4-ohm loads by descending further downward into the 2-ohm realm seems to be a borderline exercise in audio psychosis. This is one reason that I do not recommend 2-ohm speaker loads, and why the amp is designed to max at 4-ohms. Can it drive 2-ohms? Sure. Would I? No.