Adding a stereo amp to a receiver

Discussion in 'AV Receivers & Amplifiers' started by Gary_W, Apr 27, 2007.

  1. Gary_W

    Gary_W
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    Hi all,

    Not sure of the best forum to post this in as it concerns AV, 2 channel and a healthy bit of speaker so mods please feel free to move if needed :)

    The upgrade bug is biting, and it seems to be accepted wisdom here that a £1k AV amp will be worse at 2 channel music than a £500 stereo amp.

    My current setup is the Denon 3806 into AE Evo 3 front speakers (8 ohm) and it claims to fire 120w per channel into these. I am looking at upgrading the speakers and intend to audition the MA RS-8 for the front pair which are 6 ohm. The Denon claims it will whack 160w per channel into them.

    Most of the stereo amps out there are far lower than this; I can't find any in the <£500 price range that do more than 70 per channel into 8 ohms. The first contender that looks like it will do the job is the £750 Cambridge 840.

    Can someone please tell me how powerful I need to go?

    Thanks

    Gary
     
  2. Keiron

    Keiron
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    Be careful with watts. Current delivery is more important. I'm no rechnical expert but I know that a 40 watt amp I had went louder than the 100+ watt amp I have now!

    I'd get a stereo power amp and use the pre-outs of your receiver (if it has any), effectively upgrading the power amp section of your receiver.

    Look for a brand with a good reputation (Rotel etc) second hand. Power amps don't really wear out.
     
  3. Henryslater

    Henryslater
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    I've got Evo3's and a Marantz 5400 which I think throws out about 100wpc into these speakers.

    It goes plenty loud - you must have some good neightbours :rotfl:

    I realise that you may be after more 'control' but you could experiment and determine that adding a power amp makes the sound 'worse' or makes no real improvement.

    I tried bi-amping with a pair of CA amps a couple of years ago and blew up the lot - speakers included :D

    Of course, I then had to upgrade :D
     
  4. Gary_W

    Gary_W
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    Thanks for the replies so far.

    Keiron - how do you know what the current output is? Every manufacturer seems to quote watts which only tells part of the story... I did think about the power amp route, but I have certainly read opinions that it is all aspects of an AV amp (interference, component quality, pre amp, power amp) that make it less suitable. For this reason I thought that a dedicated amp that then takes the pre-outs from the AV amp for home cinema and takes the music source directly would be the best way forward.

    Henry - I realise that, for music, a 70w amp should be fine (unless you subscribe to the ad campaign by MF saying that I'd need at least 120 watts to handle the transients). The thing that gives me concern is that if I am watching a movie at -5 on the receiver (which happens) and then there is a nice explosion, I would like the 2 channel amp to be a happy bunny. Do I need to match the Denon watt for watt or is a 70w amp going to do the business? I will certainly consider the Cambridge amps (which seem to get good press) but wonder whether I really need to go up to the &#163;750 monster...

    Oh, and the house is detached. Which is just as well with the SVS PB12 Ultra sub doing its thing in the corner. Instant ASBO if you are in a semi....

    Gary
     
  5. Mark F

    Mark F
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    In my experience, no. I added a Cyrus PreXvs and SmartPower+ (60 watts) to an Arcam AVR300 (110 watts). A big improvement in stereo and also a small improvement for AV (even with the volume cranked up).
     
  6. eric2

    eric2
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    Hi Gary,

    I'm in a similar situation to yourself in that I've got a Denon 3805 and I'm looking to upgrade the stereo side. But also might change the 3805 to something that is future proof on the AV side. I don't want to be upgrading again for a long long time! My initial thought was to upgrade to one of the upcoming amps like the Denon 4308 to have HDMI 1.3 switching etc for a future HD player then add a integrated amp that can be plugged into the pre-outs of the Denon. The problem is there only seems to be a handful of integrated amps that have a AV button or some kind of switch that allows you to use the AV amp volume control for the AV side. The 3 I know that have this feature are:

    - Denon PMA-200AE &#8211; It looks a ridiculously bulky and ugly beast but I presume the Sonics of the amp would work well with the Denon AV amp.
    - Musical Fidelity A3.5 or A5
    - Cyrus amps

    I did get chance to compare the Cyrus 8 vs2 against the Denon 3806 in 2 channel and the difference was massive, which proved to me that I'm not going to be happy with the stereo performance coming from any AV amp.
    I know Cyrus are just about to release the AV Master 8 which could replace the Denon amp but sure it won't have the features of the Denon amps. There seems very little choice in the market for those wanting the best of both worlds in one setup.
     
  7. Gary_W

    Gary_W
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    Mark - That's good to know. I wonder if there is a rule of thumb for this kind of thing....

    Eric - The Cambridge 740 and 840 allow you to configure the inputs to ignore the volume control, thus allowing you to use it for home cinema. These are two of the amps I'm considering. £500 for the former, £750 the latter.
     
  8. joffy1780

    joffy1780
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    Have a look at the Arcams,which also allow this kind of configuration.I believe the A70/80(but could be the 75/85) allow this.
    FWIW I added 2 Arcam Alpha 9s to my Pioneer 1015,to bi-amp my B&W 602s,and the improvement was vast,particularly for 2 channel stereo,but also for multi-channel music/movies.

    Oh and the Musical Fidelitys A3.2,3.5 and A5 allow this also.
     
  9. KelvinS1965

    KelvinS1965
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    :thumbsup: Sorry to jump in on your thread Gary_W,:D I'm in a similar position, I've got a 3805 and I'm thinking about digging my NAD350 out of the loft now I have some decent front speakers. I figure that at the volume levels I listen at (-20 to -15) then the NAD should be able to keep up, no problem. There is so much BS talked about watts that it's hard to see the wood for the trees.:D

    My NAD350 is 80 watts continuous max, but the Denon3805 is quoted as 120 watts. I'd guess that the Denon figure is for only one channel driven and that in real world use with all channels driven it is probably less than the NAD. The other point worth noting is that you probably couldn't hear the difference between 80 and 120 watts as I believe you need to double the watts to increase the sound level by 3db (the minimum 'step' that we can detect).

    I stand to be corrected (and probably will be:D ), but I reckon quality rather than quantity should be the goal. I also agree with the poster who suggested secondhand route as power amps don't tend to wear out, maybe just the occasional crackly switch more through lack of use.
     
  10. eric2

    eric2
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    Thanks Gary,

    Let us know how you get on. The Cambridge 840 is about the same price as the Cyrus so it would be interesting to compare but I guess that's difficult as Richard sounds (as far as I know) don't sell any of the Denon, Arcam, Cyrus or MF amps.
     
  11. eric2

    eric2
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    The Denon PMA-1500AE is another option if your looking at an alternative around the &#163;500 mark. No idea whether its a quality amp or not but wouldn't matching sonics be more important than watts etc?
     
  12. Knyght_byte

    Knyght_byte
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    the 3806 will struggle to power the RS8's in multichannel properly, it will handle them to a degree but bug out during massive on screen moments....you'd really need the 4306 at a minimum for speakers that large...

    people often assume because you cut the bass at 80hz to the sub that the floorstanders bass drivers wont be doing anything, wrong, they handle freqs above 80hz.....so you get more powerful sound, but only if the amp can handle...

    so you are right to want to add a stereo amp.....

    personally i'd say go 12 months interest free somewhere and grab an MF A3.5 as it has the HT input for multichannel use......its a brilliant amp, will happily handle the RS8's :)

    otherwise, only amp that will have the power close to your price bracket is the Roksan Kandy......

    however i'd seriously recommend you get demoing in the shops to see what the differences are, possibly even consider a home demo if the shop is willing...
     
  13. Gary_W

    Gary_W
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    Thanks for this. The MF stuff does look lovely, but I'm already pushing it with the concept of the MA silvers all round (I need a 7 speaker set) so the outlay on that lot is upwards of £1.5k before I've considered updating the amp :eek:

    Regarding your comments as to the 4306 being able to handle the MA's but not the 3806 - I'm not disagreeing with you, but please could you tell me more about why you believe this to be the case. On paper, the 4306 has 10w per channel more and that's about it in the sonic department. What is it that makes the 91dB RS-8s difficult to drive on the 3806 that the extra 10 w on the 4306 fixes? If it really is the case that 120w is not suitable to drive these speakers (which is what the MF advert suggests) then looking at the 120w Cambridge is pointless...

    Gary
     
  14. ssuellid

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    My old Denon 3802 has no hassle driving my Dynaudio 62s - a far harder load, according to the specs (4ohm 86db), on an amp than the RS8s. This was to extreme drunken detached house volume levels.

    My Cyrus 6 and 8vs stereo amps did struggle to drive the Dynaudios tho for AV - fine for stereo use. But I know of people using the 8vs with the RS8 and apparently it works fine - tho I find MAs a bit bright for my liking.

    Nice feature of the Cyrus amps is that you can fix the volume on the AV input - so no faffing about getting the front stereo volume right when you use it in an AV set up.
     
  15. Knyght_byte

    Knyght_byte
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    ok, those channel power figures are when driving a single (or sometimes two) channel at a single frequency to a certain level of THD......with AV amps they usually allow a much higher THD before considering the sound to have suffered.....

    when you are driving most of the channels, you will seldom get near to the rated power, especially in scenes with massive transients....

    the 4306 has a different PSU which is more capable than the 3806's.....i forget now where i read that, i dont tend to bookmark very much..lol....so although it only looks like 10 watts extra, when all channels are driven it provides more than that.....and its PSU is more reliable with big demand swings...

    a quick example, my Denon 3803 is supposed to be able to output i think 110watts on 8hms or 150watts on 6 ohms....however with all channels driven it peaks around 50watts a channel iirc......luckily its pretty good with transients so it copes just about with my Silver S6's.........my Musical Fidelity A5 however is quoted at 250wpc, and given it has a 750watt consumption, accounting for pre-amp stage, LED's and heat loss, it can actually provide that 250wpc because it has a state of the art PSU and high quality power stage.......but then the 3803 cost (rrp) &#163;900 or so for a 7.1 channel full on AV receiver, the A5 is a fairly basic dual mono integrated costing (rrp) &#163;1,500......
     

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