Just a power amp, turntable and speakers?

What is the reason that you need a pre-amp? If I only want to listen to records on an older Marantz turntable, can I simply run it into a high powered power amp and out to some floor speakers? I'd be interested in hearing any and all opinions/input on this topic.

No, you need at least a phono preamp with a volume control.
(Very few phono preamps have volume controls, which is why most people, myself included, have a preamp with either phono boards, or a seperate phono preamp.) The phono preamp is also necessary to correct the cartridge's signal. It comes out of the cartridge with a RIAA std. phono curve signal, which needs to be corrected, or else the sound would not be a flat frequency curve.

Hope that helps, (and I am sure you will get a lot better, and more detailed explaination from others on this site.)
Nope. Generally, the TT needs a phono preamp and you also need a volume control somewhere. Get both in a preamp.

unless you are mistaking a power amp for a receiver.Then your phono preamp,volume and tuner are all included.20+ years ago.
you could get an amp with volume control, but you will still need a phono-pre. You could do an integrated, although i do not know it any integrateds have phono stages.
get a vintage marantz integrated amp....plug your table in.....you are home free.
I actually just got an HH Scott 436 integrated unit, but it seems like it's a little underpowered for the speakers I'm running. I was just wondering if I could employ just a Crown or Marantz power amp alone, and take the Scott out of the picture since the turntable is the only input. (I only have experience with modern integrated receivers)

Any suggestions on an appropriate power amp to pair with the Scott 436? Is there a reason to avoid a late model Crown? Or should I go with something more age appropriate?
As has been said, you need a volume control in the circuit, which is what a preamp does. Otherwise it would simply play at full volume all the time. Plus you must have a phono preamp, either built in to the system preamp, or a separate unit. The phono signal is very low output, plus it is equalized with an RIAA curve, and sounds horrible without the proper re-equalization.
Does your Scott integrated have pre-amp output jacks on the back? If it doesnt, you cant add a separate power amp to it.
Yes, the Scott unit does have a pre-out.
Are you sure that it is pre-amp out, and not just a tape out, which will not have volume control.
Damn, you're right. It's just a tape out. I was thinking it had a true pre-out because that's what the seller told me. Not a big deal, I didn't pay much for it.

I'm going to get something new I think. I'll read up a bit on this site first, for sure.