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Using combo amp as cab

Discussion in 'Amps and Cabs [BG]' started by lowfrequency, Jun 16, 2002.

  1. This may be a silly question but...

    Is there any way I can use my Peavey TNT simply for the speaker - powering it with a separate head?

    Thanks kindly,
  2. Ty McNeely

    Ty McNeely

    Mar 27, 2000

    Yep...most likely.

    Depending on what choices you have, you can run a line out from the head to the "Power Amp In" of the TNT, or you could run a cable from the "FX Out" of the head to the "FX In" of the TNT.
  3. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA
    Power amp in is indeed an input designed for speaker only. I haven't seen a TNT in forever, so I don't know if it has that input or not.

    BUT, if you do this: "you could run a cable from the "FX Out" of the head to the "FX In" of the TNT."

    You are running off the power amp of the TNT, not the head. It will work, but you would be using only the preamp of the head.

    This is fine, as the speaker likely isn't rated for more power than the amp in the combo can deliver, so you aren't loosing anything. However, if you are trying to get the tone of the head, you might not. Depending on how much the power stage of the head effects the tone.

  4. Chas, Hunter,

    Thank you.

    Before your replies, I was a little leery of plugging a head into the "Power Amp In" - the manual states that this input is "provded for in-line patching of effects devices" but says nothing about bypassing the internal amplifier.

    2 more questions:

    Will the speaker work without the power to the TNT on?

    The speaker in the TNT is rated at 150W - can I use a 200W head so long as I don't turn it up too loud?

    Thanks again,
  5. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA

    The manual's description sounds like a description of an effects return. It is, in fact, a "power amp in" in that it is an input straight to the power amp. It DOES NOT sound like a place to plug in another power amp.

    I STRONGLY suggest you contact Peavey and get the real scoop before you plug anything into anything.

  6. K-Frog


    Feb 6, 2002
    Camden, AR, USA
    At least not without a simple mod. The PWR amp in is indeed only to plug something(preamp) INTO the power amp section of the combo, NOT to plug a power amp into the combo. You will definitely let the smoke out of your amp doing so.
    The simple mod is to use a DPDT switch and another 1/4" phone jack to plug a head or pre/power amp into. You have to use the switch to take the combo's head out of the speaker circuit. Wire the speaker to the middle teminals of the switch, the head to the two terminals on one end and the 1/4" jack to the two on the other end(a DPDT has 6 terminal, 3 pair). Switch it one way and you got speaker hhoked to combo head, the other way and you're connected to 1/4" jack and combo head is out of loop.
    The speaker will work without the combo being turned on if you're just using it as a cabinet. Speakers are passive in general, it's the "other" head that's going to do the moving and shaking.

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