Is it ok to use a two channel amp for front L/R and use the receiver for the rest?

Discussion in 'Archived Threads 2001-2004' started by Kyle_Y, Feb 15, 2002.

  1. Kyle_Y

    Kyle_Y Stunt Coordinator

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    I just bought an Onkyo 797 which I really love, and it give me a lot of power, but can I use an extra two channel amp to power my front speakers? Will this throw off the balance of the sound? Won't the front L/R be louder than the others if I do this, or does it just work out? Or do I HAVE to buy a 5ch amp? I ask because for stereo purposes, I wish there was a little more omph for my 4ohm towers. I am looking at a Rotel or Parasound...favoring a Parasound HCA-1000A, or maybe a HCA-855A, but I would rather have the extra omph in stereo, no extra in surround is needed, can i just buy a 2ch amp?
     
  2. John Tompkins

    John Tompkins Supporting Actor

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    Kyle, there is no problem at all doing this. You can always db the volumes levels using the onkyos test tone and a rat shack meter.

    Having said that if it were me and I was only going to purchase one 2 channel amp with no plans on getting another 3 channel amp down the road, Then I would opt for a 3 channel amp as to keep the front soundstage on one amp..thanks
     
  3. Kevin. W

    Kevin. W Screenwriter

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    Yes! All its needed is a little calibration. The only problem I can think off is, you may get a different soundstage coming out from the centre because of the amps in the receiver and amp will be different.

    Kevin
     
  4. Chris PC

    Chris PC Producer

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    Yep. That'll work. You'll have more power for the other channels and if the main 2 channel amp you're using for the front speakers is good enough, it'll realy boost the sound quality and volume overall. I wasn't too fond of the Onkyo 797 music quality, but the receiver in general is really good. An amp is perfect to round it out.
     
  5. Kyle_Y

    Kyle_Y Stunt Coordinator

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    In that case then, what are some good 3ch amps under $1k? Would it be possible for me to buy a 5ch Parasound or Rotel, and bridge it, so that I am left with two bridged channels and one not bridged which I would use with my center? My center is 8ohms, or would that still distort the front soundstage? I really like the Parasound amps, but they do not have a 3ch amp, I was hoping I could bridge the 4 of the 5 to make that the front l/r and use the remaining channel for the center, ok, or just buy a 3ch amp? If so, which one?
     
  6. Leo

    Leo Second Unit

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    I did the same thing with my Yamaha 995 as a pre/pro and added 3 Marantz MA500 to power my front soundstage. The monoblocks for me were a better choice because I have plenty of flexibility to add more monoblocks when needed (I will be adding the last 2 channels for the rear at the end of the month - shopping around for 2 more Marantz monoblocks).

    Leo
     
  7. Kevin. W

    Kevin. W Screenwriter

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    Kyle_Y,
    Rotel make the 6 channel RMB-1066 which can be configured to 6x60, 5x70, 3x150 with combinations in between. Its an excellent piece of hardware in my opinion(currently have one). Should be easily had for about $500-600US. Here's a link to the specs:
    http://www.rotel.com/products/rmb1066.htm
    I've heard that bridging can effect the sound quality produced but I wouldn't know what to listen for. I've bridged the amp and ran my fronts(Paradigm Mini's/CC-350) at 3x150 and couldn't detect any sound degredation at all. If anyone has a link to info on bridging that refers to this problem I'd appreciate it. Down the road I plan on adding another one of these to my setup and running it at 6x150.
    Kevin
     
  8. rodneyH

    rodneyH Supporting Actor

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    Kevin, I have a the Rotel RB-976, it looks like the 1066 has replaced it, but in reality they are the same amp exept for the front heat sinks. The specs are EXACTLY the same, so I assume they are the same amp. Having said that I like my 976, and think it was/is a VERY good value.
     
  9. Kevin. W

    Kevin. W Screenwriter

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    rodneyH,

    Question regarding the gain nobs on the front. Have you ever played around with them? What are they for? I almost bought the 976mkII a while back when I first was looking at amps. I'm glad I waited cause another dealer sold me the 1066 for $50 more than a demo 976. Both are excellent pieces of hardware with the Rotel name.

    Kevin
     
  10. Kyle_Y

    Kyle_Y Stunt Coordinator

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    I have just one question. The 1066 bridged to three chennels sounds great, but my front tower speakers are four ohms, in the manual, it says that in bridged mono mode, the impedence can only go as low as 4ohms, will I not be able to do this? I do not have a Rotel authorized dealer or service center in my area, so I will have to buy it used, and I don't want it to get here and I find out that the amp will not drive my speakers. It sounds like a good idea though. So does this mean that according to the manual I downloaded, that if I bridge the 1066 into 3x150, that I have to use 8ohm speakers[​IMG] ? If it will absolutely not work, I may have to spend the extra bucks for a 5ch amp or just buy a 2ch amp even though the front soundstage may be a little off.
     
  11. Alex F.

    Alex F. Second Unit

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    I can heartily recommend the superb Adcom GFA-5503 three-channel amp (200 watts/channel @ 8 ohms; 350 @ 4 ohms). Smooth, clean, open, liquid, with great soundstaging, rugged, and affordable. Available at Audioadvisor.com and elsewhere.
     
  12. rodneyH

    rodneyH Supporting Actor

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    Kevin, I really don't know why they would put the knobs on the front (many of the other rotels have gain controls, but are much different style/small flat head screw driver types).

    I don't really use them too much, since my pre/pro (parasound avc-1800) have all of the adjustment internally, like all/most pre/pros and receivers. I have used them a few times in the past but I acn't even remember off of the top of my head, why I did. If the option wasn't there, I don't think it would matter too much.

    I have been using the unit to power my front 3 speakers (B&W CDM7NT, and center), and have used an 80 watt/channel NAD for my rears. I am stepping up to another amp of my mains (the 400s from marshsounddesign.com), It is supposed to be a very very good amp, and some say far better than its (relatively) low retail price of $2300, some reviews say that it competes with the amps double and triple the price. Not that I am not happy with the Rotel, but I have a very good freind in the audio business and he is gettting me the marsh at a GREAT price, and since that means I not only upgrade my amp to my mains, it also means I can use my rotel (@150 watts) instead of my NAD (@80 watts), so in reality, I am upgrading 2 pieces for the price of 1.

    If I had to pay full or close to full retail, I would buy the rotel stuff-NO QUESTION (actually I get the rotel stuff at over 20% off, but the other amp is a deal I can't pass up)
     
  13. rodneyH

    rodneyH Supporting Actor

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  14. Kyle_Y

    Kyle_Y Stunt Coordinator

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    Rodney,

    I'm sorry, is the 400s a 2 or 3 channel amp? Ideally, I want to just buy a 2ch amp, since I only want more power to my front L/R, but if it is goign to make an obvious difference when panning, then I don't want to do that. The Adcom 5503 Alex mentioned is too much, $1500 retail. I can get a very good 2ch amp used for $700, but for a reasonable 5ch amp used I will have to pay at least $1k and I only need 2channels, and I can't seem to find a good, not too expensive 3ch amp.
     
  15. rodneyH

    rodneyH Supporting Actor

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    ya, it is a 2 channel and it is about $2300 in price. So, it may be a little more than you wanted, BUT if I were you I would get teh rotel 1066 (3x150) for around $500-600, then later if you ever want to upgrade get a "better" 2 channel. For the $ I think that the 1066 is a great deal and that is why I did it (but the different part # at the time I bought). I think that that is a good way to start getting into seperates. I first got it with a my recievers-Yamaha 793, then the yammi 795, then the 995, then I finally got a pre/pro (since I could finally find one at under $1000). I bought the NAD amp off of a freind (his Bro is the guy who owns the dealer I know) and got it for like $200-used, so it was a relatively inexpensive way to have seperates.

    Have fun
     
  16. Kevin. W

    Kevin. W Screenwriter

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    Kyle_Y,

    Basically when you bridge instead of seeing 8ohms as 8ohms the amp see's it as a 4ohm load. Since your speakers are 4ohms the amp would then be seeing a 2ohms load which I wouldn't recommend for the amp. What make are your speakers? It will be a hard decision between the Rotel and Parasound. With the Rotel you get the flexibility of bridging and since you would only be powering the fronts 70w vs 85w for the Parasound HC-885A

    Kevin
     
  17. Kyle_Y

    Kyle_Y Stunt Coordinator

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    My Speakers are A/D/S speakers rated at 4ohms. My previous Pioneer DTS DD receiver would go into overload protection often so I had to get the Onkyo 797, which has never gone into protection thankfully, and it sounds very good for a receiver, but I would like a little more, which is why I am asking about a new amp. Maybe I shoudl just wait and buy a Parasound 1205A which is THX ultra certified with 125x5. Adding an external amp is not a priority for me, but it is something I want, and later I can always sell the 797 and buy a pre/pro.
     

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