turntables

Dear @g_nakamoto: Mainly depends on what level of quality performance you want to listen and how many LPs you own.

Pioneer design good, very good and excelent levels of products. Your TT model is not really in any of those levels for today standards, it has really poor measures as specs.
Of course that can works at some limited quality level performance. Its tonearm is not good neither.

You can get an inexpensive Pioneer vintage TT looking at the 600 series, as the PL 630 that's very good motor with good tonearm.

As I said all depends on what you want.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

I bought a PL-71 in 1974 from Radio Shack, when I was attending a university in Cookeville Tn.  Back then, there just weren't many Hi-Fi stores around, unless you went to Nashville, even then maybe a couple.  Audio Systems and Nicholsons.  Anyway, I stopped playing vinyl around 1987 and went to the CD.  About 8-9 years ago, I decided to get my old Pioneer back out and started with replacing the stylus in the original shure V-15.  After trying a few different cartridges, I installed a Koetsu Urishi Black.  It sounded awful until I beefed up the mass of the tonearm.  The difference was like day and night-truly.  I lubed the spindle and cleaned the pots that adjust the speed and the performance of the old Pioneer is very good.  Some can't tell the difference between it and my VPI Scoutmaster.  Proper motor speed, good flawless arcing, sufficient tonearm mass and of course proper cart set-up is all I need.  The main thing I found, was the stock tone arm just didn't have enough mass.  You really have to experience this, to hear the difference and it's amazing what increasing the mass will do, for the sound.  Definitely keep the "51", get a good cart and experiment.  

Dear @handymann : " keep the 51 ".  Depends on what the OP is looking for.

In the other side the 51 and 71 are not similar TT. The 71 had a way better tonearm and I mean by a wide margin and its motor was better too. You can't compare in between and think that in both TTs he will has same quality level performance because it's not that way.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R. 

Let me amend my last post about the PL -51. Why not buy a good cart, like the Lyra Delos and install it on the 51. If results are not satisfactory, invest in a new TT and put the new cart on it. Nothing ventured-nothing gained. 

If you enjoyed that tt when you used it many years ago - and the rest of your gear is similar in quality ( in other words - you haven't had upgraditis for the past 30 years) -  then a new stylus is likely going to get you where you were - and that might be just fine -  but just make sure the tracking and alignment get properly adjusted at the same time -  if the kids ruinined the stylus - chances are a proper set up and once over by a qualified shop is in order - I know in Toronto - one retailer offers this service incentive per year for free - obviously to sell gear - but - you may only need a new stylus