Ok, there are $300 receiver with 100w, and $2000 power amp with 100w. What would be different? Is it just a matter of someone lying or bending truth in terms of their spec? I know high current gives you better sound even given same wattage. However, even that "high current" seems to be relative since pretty much every makers say their amp is high current. So, back to wattage, what would I get from 200w amp which I couldn't get from 100w amp? Would it just sound louder at same volume? Or, would it bring out more details in low volume? Are all 200w amps need separate circuit to run reliably? Lots of question...
Yoon, You have opened a Pandora's box. First series of questions: you should expect a world of difference between a $300 100W receiver and a $2000 100W amp. In the first place, the receiver is very likely not giving you 100W and the transient situations where it might even come close to fulfilling that are few and far between. MOST receivers are rarely capable of giving their stated continuous power unless they are a good bit more expensive than your example. This is becoming more of a truism than ever with the continuing growth of multi-channel. Consequently MOST sub $500 receivers will never measure up to their power claims. IMO, some of it is deceptive (as in 'read the fine print') and other results show something more obviously false. In the second series of questions, you would hear a 3dB increase at a minimum which on most systems is a (-)2-3 click on the volume to achieve the same sound level. The sound quality jump from receiver to amp should be more noticeable than the switch from amp to amp but this is a generalization. What is most critical in determining the advantages of any particular equipment in this kind of analysis would be having a neutral, accurate speaker set. Any changes to the overall level of detail, coloration (if any), fullness and accuracy of sound at the volume extremes, etc. can be better appreciated with such speakers.
It depends on how they rate the 100W. Most high end separate amps rate it at full bandwidth(20Hz-20KHz), at a low THD(>0.1%), at an 8ohm impedance and with all channels driven. Lower end receivers might rate it at a single frequency(usually 1KHz), at a higher THD(1%), at a lower impedance(6ohm or 4ohm) and with only 1 channel driven. Denon has been known to rate their receivers at 6ohms, which raises their power output. Also, the headroom would be different. Better amps will also be able to almost double their power output with a halving of impedance. For example, an amp rated at [email protected] will be able to produce close to [email protected] A receiver rated at [email protected] might only produce [email protected] It all depends on the size of the power transformers, the capacitors and output stages of the amplification stage. The larger these are, the more power the amp can produce.
The way the power output of a receiver is specified is set by the FTC. I've never come across a receiver that didn't meet its power specs as so measured. The reason for a 200W amplifier is because 100W is not enough to get the loudness you desire, resulting in distortion. You can of course decide to accept a lower volume level, and then 100W may be entirely satisfactory.
