Speaker ratings, amps & turntable?

The noticeable improvement will come from getting a better amplifier than the one found in most receivers. The Denon 3802 is good for movies, but you can do better than the Denon for 2 channel music. Most HT receivers do not put out their full wattage across all channels across the full frequency range.

Also, it is not always about the wattage ... speakers are more likely to get damaged as the amp goes into clipping (runs out of power) and the power that is produced is "dirty"/more distorted.

With all that said ... what's your budget for this? The NAD C372 comes to mind as a well regarded modest cost integrated amplifier that might work for you. You would most likely need to add a phono preamp to the NAD, which NAD makes for about a $100 more.

Regards, Rich

First of all, increasing the wattage has nothing to do with hearing a significant improvement. Many expensive SET amps only put out 2 to 10 wpc. Many SET fans say if the first watt doesn't sound good, who wants 200 more watts?
Of course your speakers have to be efficient enough to use flea powered amps like these (usually horns).
So quantity and quality are not related.

Now it gets more difficult, because quantity does not always equal quantity. For example, a 100 wpc Krell amp will drive your speakers louder than a 100 wpc receiver. Why? Because of the beefier power supply, which will provide more dynamic headroom. In other words, a 100 wpc Krell amp will play louder than a 100 wpc receiver before clipping sets in.

Now, that being said, Rich is right in that most speaker damage occurs by over driving an underpowered amp (clipping) than by driving a higher powered amp. In other words, it's harder to damage speakers with 'clean' power. The Hafler you are looking at is almost double the B & W's recommedation of 200 watts, but is probably less likely to damage your speakers than a 50 watt amp or your 100 wpc receiver. Your speakers are rated at 90 db sensitivity, which means that 100 watts will provide 110 db at 1 meter. That's pretty loud. It's unlikely that you will ever use more than 100 watts. Most of your listening is probably using 0.5-10 watts per channel.

Bottom line, the Hafler should be fine, as long as you don't turn the volume up to 11. :)

Cheers,
John