here are typical rear panel views of amplifiers
here is a typical rear view of a avr
as far as what the differences are... you may want to read this thread:
http
/www.avsforum.com/t/1345971/stereo-receiver-vs-amplifier
basically a avr is a preamp+amp+media functions (radio, mp3,video processing, etc) while amps can come as just an amp requring a seperate preamp to control volume or can be integrated preamp+amp so that they do control volume.
a avr is able to switch between any of its sources easily while not all amplifiers have this option.
if you have many input sources a avr is likely best. if you have a single audio source an integrated amp (with volume control) is likely going to get you more for your budget. of course you may want the features of a avr... i dont know. i'm just listing differences.
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i can only go by prices i can find. i'm not familiar with all of the popular hotspots in eu for speakers so i only use ebay.co.uk, amazon.co.uk and google to see what prices i can find. it looks like you get the wharfdale 10.1s for about 70gbp less than we pay. keep in mind the prices i listed above were usd (if i didnt specify gbp then its in usd)
since you did save a bit this means you would have a few options..
-you could get a center speaker maybe (going to be tight on budget)
-you could step up to 10.2
-step up to a receiver with 10.1
-just keep the extra cash in your wallet
-perhaps have enough budget for a cheap subwoofer
of course it all depends on the deals you can get and if you like the wharfdales to begin with.
there is another thread where a guy got them and likes them though. your choice.
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amplifier and avr output different wattages at different impedences. this is often listed on the spec sheet.
for example a dennon avr-e200 (not i'm not recommending this one just providing it as an example) has various outputs
at 6ohm it outputs 110w per channel
at 8ohm it outputs 75w per channel
it has a maximum power output of 165w per channel.
http

/usa.denon.com/us/product/pages/productdetail.aspx?pcatid=avsolutions(denonna)&catalog=denonna_us&catid=avreceivers(denonna)&pid=avre200(denonna)
now i'm not any audio expert by any means. there are a few people more well versed than i am but from my own research...
if an amplifier is not able to handle the load you can get clipping. basically the ends of the wave are cut off. again i'm not expert but i believe this is how you can damage your speakers.
this is why the maximum output of the amp or receiver should be larger than the typical requirements of the speakers.
ie if you have 100w speakers at 8ohm a receiver which can output at 100w/8ohm is likely going to work if the maximum output is something like 165.
then speaker sensitivity comes into play. i've heard that high speaker sensitivity means you can use a lower powered amp and it still works. honestly that part has me confused as well.
the diamond 10.1 has a max power handling of 100w/6ohm so something like that receiver would work at 110w/6ohm, 165w max. i believe volume has to do with how much power is used as well. the speakers might not be using 100w all the time.
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100w@6ohm is a fairly common figure for bookshelf speakers.
i would not just go connecting any old speaker up though as speakers often sound better when matched in sets.
ie a full diamond 10 system will likely sound better than something hobbled together from 4 speaker brands. of course you can put together a system and have it sound good but you really must know what you are doing.
if you want to go bigger than 2.0 in the future perhaps an avr is a better solution? lots more inputs, it has video processing, 5.1+ support and in general its more upgradeable than a stereo amp which will always be stereo. of course they do make amps in 5.1 i believe but they are typically more pricey than some of the lower end receivers.