1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

power amp thru FX loop...

Discussion in 'Amps and Cabs [BG]' started by Hrothgar, Nov 30, 2004.

  1. Hrothgar

    Hrothgar Guest

    Sep 22, 2003
    I just ordered an Acoustic Image Focus 1R and had a question about something. If you plug in a separate power amp thru the effects loop does it by-pass the head's power section or add to it? Would that affect the minimum resistance load? If someone could tell me how that works, I'd appreciate it!
  2. ErnieD


    Nov 25, 2004
    :hyper: I just posted a similar question on the other "Should I power amp" thread above yours. They are saying to run the power amp to your line out in your head. Maybe check that thread later for a reply of you don't get a clear answer here. I am waiting for a similar reply, though you have some other good questions here, hope they can help us. Later.
  3. jondog


    Mar 14, 2002
    NYC metro area
    Power amps are not additive. You cannot plug one power amp into another -- if you do you will release the magic smoke. If you want to use multiple power amps, you need multiple cabs. An fx send would be before the power section.
  4. LajoieT

    LajoieT I won't let your shadow be my shade...

    Oct 7, 2003
    Western Massachusetts
    I'm no amp expert but if I understand correctly you are asking about taking the effects loop signal output, feeding it into a power amp, and then feeding the power amp output back into the effect loop return of the original amp? If I'm right with that understanding I'd strongly suggest you not do it. I'm quite sure that there is no way that the effect loop return circuit can handle a high power signal like that and will likely fry.

    Of course I may not have understood your original intent...
  5. Hrothgar

    Hrothgar Guest

    Sep 22, 2003
    It says on the Aoustic Image website in the owner's manual that you can run a separate power amp through the Send jack (it becomes a line out) of the FX loop (or a separate Preamp through the Return jack). I'm just confused on this: it is a parallel FX loop, which means it does not interrupt the original signal. So when you put a power amp through it does it then interrupt the signal flow to the power section and "take over" or is it used separately to power another speaker and the original signal is not interrupted at all (which seems the more plausible scenario).
  6. Hrothgar

    Hrothgar Guest

    Sep 22, 2003
    it seems we have similar questions, but mine is a more specific one, since I already know how to plug in a power amp to my head. My question is will it (1) interrupt the signal flow rendering the head's power section useless, or (2) not interrupt the signal flow and become a separate power amp that is just 'borrowing', per se, the head's preamp section giving me, in essence, what would amount to two heads? And are there any concerns about this?
  7. IvanMike

    IvanMike Player Characters fear me... Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    generally speaking, plugging a cord into the effects send jack of a head does NOT interrupt the signal going to the power amp section of the head. Plugging a cord into the effects return jack of of a head does. Some amps like most SWR heads have a side chain effects loop which allows you to blend the signal from the effects return with the original signal, so as long as you don't have the effects blend control set on maximum (wet), some of the original signal still makes it to the poweramp of the head

    So............ If i understand you correctly, you're thinking about using your effects send as a line out from your head to a seperate poweramp to drive more speakers. (BTW, plug the speaker out of a poweramp into your effects return of your head and kiss your amp bye bye). Using the effects send as a line out generally works just fine. Both your head's poweramps section and your second poweramp will get a usable signal from the preamp of your head. I've done this a gazillion times. There are a few heads such as eden where the effects send is pre eq and very low level and is no good for line out type signal. I'm sure yours is fine.
  8. Hrothgar

    Hrothgar Guest

    Sep 22, 2003
    Thanks for the help!! that's eaxactly what I was looking for.