Just because a speaker can absorb 250 Watts doesn't mean that 250 Watts will make it sound better. Wattage ratings on speakers are almost worthless. If your current system produces enough clean volume for you that's all the power you need.

Most Onkyo TT's have never been considered "high quality".

IMO all receivers are mediocre.

What about your current system are you unsatisfied with?

The power rating on a speaker is like the speed rating on a tire.

You don't need a 130 MPH car becuse the tire is rated for 130 MPH, and you don't need 250 watts because the speakers have that rating.

The 250 watt rating is the approximate power level at which you will melt and burn out the speaker coils.

The SENSITIVITY rating is what allows you to figure out the needed power. If the sensitivity rating is 87 db per watt or more, 60 watts is adequate.

I suggest that you buy a Music Hall A15.2 amplifier from Music Direct for $499. IMO this is just about the best integrated amplifier you can buy for under $1000. It sounds really good, and even has a phono stage built-in to connect your turntable to. It will make your system sound a lot better than an old Denon HT receiver.

The second thing I would do is invest in a Music Hall 2.2 turntable, which generally sell for $450 complete with cartridge. It is very good for the money, and will be another big improvement.

Those are very old speakers, but they were very high-quality in their day (unlike the trash sold today with that name on them). If they sound good...what the heck.