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2 pre amps - 1 L/R Power amp

Discussion in 'AV Pre-Amp/Processors & Power Amps' started by grey torq, Jul 27, 2005.

  1. grey torq

    grey torq
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    I note that some of the newer (expensive) stereo power amps have more than one input an 'A' input and a 'B' input selectable from the power amp. This allows you to have a hifi for music pre amp on the 'A' input and a processor for movies on the 'B' input.

    My question is that I am about to go for a setup like this but I can only afford a power amp with one set of phono inputs, do I have to keep plugging in and out when I switch from movies to music?

    If I used a phono 1-2 adapter and plugged one of these into each power amp input and then connected both preamps would this be safe as long as only one preamp was on at a time - or are there electrical dangers I am overlooking?

    Appreciate any advice.
     
  2. Joe Fernand

    Joe Fernand
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    grey torq

    If your power amps have a single line Input would you not 'cascade' the front Left and Right multi channel Outputs from your AV Processor via your HiFi Pre Amp/Line Stage?

    Best regards

    Joe
     
  3. grey torq

    grey torq
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    Err yes this is what most people do by way of compromise but the signal path is source -processor(pre amp) - hifi preamp - power amp.
    There are 2 preamps in this path each with variable volume this can not be ideal even if it is conveinient.
    Idealy you should go straight from the processor to a power amp - hence my question above.
     
  4. Joe Fernand

    Joe Fernand
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    Hello grey torq

    That'll be:

    Multi-channel source > AV Processor (front LR) > Line Stage > Power amp

    or

    Stereo Source > Line Stage > Power amp.

    Granted the volume issue may be tricky to begin with but will you really 'hear' a big drop in signal quality running the Front LR from your AV Processor via your Line Stage?

    You could always introduce a 2 (or more) to 1 Switcher with Stereo audio in and outs - if you got one with IR control you could integrate it into your set up and ensure the Power amp never 'sees' both 'sources'.

    See http://www.zektor.com/hds4/index.html

    Way more features than you need so possibly you could find something simpler for less money.

    Best regards

    Joe
     
  5. booktrunk

    booktrunk
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    I understand what you want just a set of reverse splitters in the input to the power amp. So that you can just plug both in.

    Sounds easy enough, but i've no idea how upset the power amp or the speakers would be when you accidentally leave both on so you have both of them putting stuff into the power amp I guess it would just sound awful. :)

    A small QED switch would resolve this issue not sure what effect it would have on quality.

    With regard to having the seperate stereo pre-amp and the A/V amp or processor. If you haven't already got all of your kit and you can get a stereo power amp that does have a pass through for an A/V input this really is the easiest answer. Or instead of a seperate power amp a stereo amp of high quality that includes the passthrough. That way you get decent stereo and your A/V sytem with no problems at all.

    I do this with my Rotel 1068 and 5 channel power amp. I have a Musical Fidelity A308 sitting on the front of this for stereo duties. The pre-outs from the A/V Processor go into the Aux2 input on this amp which is configured as the A/V input no messing about with volume on the A308 it all just works.
     

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