Perhaps a Stupid Question

+1 What millercarbon said.

I have a Pioneer PL-630 turntable and hardwired it with shielded (cotton) 20GA Duelund wire and KLEI Absolute Harmony RCA plug IC’s.

You’re going to have to decide if you need shielded or unshielded though.

The improvement was noticeable right away and improved more with burn in.

I got my ’custom handmade’ IC’s from Chris Webber of parts connexion for a reasonable price, especially since only one pair of KLEI Absolute Harmony RCA plugs were needed for one end.

I’m still deciding on what power cord to use as some are just too big and not to flexible enough but I think I have it narrowed down to a (used) Triode Wire Labs 12 plus American Series power cable.

I would buy a BlueSound Node 2i and listen to high res and MQA.  Time to leave the antiques behind.

To put it kind , all cables from before 1990 are no good and needs to be replaced!!! 
In My Own Opinion 
And be aware of hevy metals in the solder =)

@jrpnde, I would do what millercarbon suggests, but then look into going two steps further.
1. replace the tone arm wire with litz2. replace the crap headshell leads with cardas or some other litz.

once you do that you will be shocked at super level your TT will perform at.

and as others have noted, you can go nuts on IC replacement cables, but just be sure what ever brand you select is shielded.

MM and MC carts do not do well with un-shielded  cables.....

Unless you're comfortable with soldering, and think you can do a job that will do justice to an expensive audio cable, I would leave it alone.  Changing the power cable is just nonsense though.

If it is the original, I would suggest replacing the ribbed platter mat. I did this with my old P112-D. A felt replacement should be inexpensive. IMO vinyl should be supported under the entire playing surface and clamped to even out minor warps.

If you opt to replace the IC, it may behoove to replace the wiring in the tonearm to the cartridge...

Would require a careful investigation of the manner and means the originals have been routed, and how 'permanent' they'd been done.

I've done this sort of activity, but it's not for the impatient nor clumsy....

Do what @millercarbon says. He hooked up my system with tweaks and knowledge and mine sounds better than the best in any showroom. 
Everything counts 

glupson

LP on one of the pictures seems to be bigger than the platter. Wouldn't that have some potential effect on vibration, or something else?

Not necessarily - some turntables are designed that way. If you look at the profile of an LP, you'll see the center label area and the outer edge are thicker than the rest of the LP itself. That's a throwback to the days of automatic record changers and stacked LPs. (With the raised center and edge, the grooves of a dropping LP theoretically wouldn't contact the LP below.)

This can be used to advantage today, especially on a turntable with a threaded reflex clamp. If the LP extends beyond the platter, the LP can be made to be flat against the platter. If the platter and LP were the same width, the LP would be "dished" if you tried to clamp it to the platter.

elliottnewcombjr,

That turntable is truly interesting, but I have a question.

LP on one of the pictures seems to be bigger than the platter. Wouldn't that have some potential effect on vibration, or something else?

If you do change the cable, then consider that you will buy an expensive cable, and most likely want to use that cable later on a different TT or Tonearm.

Solder cable with RCA Male; solder RCA Female Jacks at TT or somewhere. Solder Din connector at TT, or somewhere?

Another reason I would not change it now.

I seriously doubt you will achieve an audible difference. If the cable was deteriorated, that’s a different issue.

I would look to upgrading the TT sometime, perhaps one with the potential to change the tonearm.

Think long range now, what arm(s), cartridge(s), alternate mono cartridge; future phono input(s), try MC someday? (I finally did age 72).

These will definitely have audible differences.

mono lps definitely sound better played with mono cartridge, no reaction to vertical movement, and with stylus shape for those size grooves.

smaller size table choice: single arm with removable headshell, primary headshell stereo cartridge; occasionally change to headshell with mono cartridge. Each time adjust tracking weight and anti-skate. You get pretty quick after a while. Most probably just use the resulting VTA the arm height is set for the Stereo cartridge. Back to stereo headshell, readjust again.

or, larger TT for two separate arms

It took me a whole lotta years, joined this forum, ... I changed everything for two separate tonearms, setup ready to use, back and forth mono/stereo effortlessly during a listening session.

Stereo cartridge in main arm; mono cartridge in 2nd arm. I wish I did it years ago, never paid attention, never occurred to me I would do this.

check out this, 3 arms, fairly compact,

https://www.ebay.com/itm/Transcription-turntable-Denon-DP-3000-tonearms-Grace-960-Grace-565-Denon-DA50-/114368866746?nma=true&si=8bF7YGBC7gvXGQ0%252B95%252Ba638%252FNKE%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

listing ended, but no bids, could make seller an offer, but local pickup NJ. If I didn’t have my current setup, I would run to get it.

Check out the round tonearm base(s), rotates to achieve different arm lengths with a single hole. I like that idea.

When you have done what Miller says, look into some not-too-crazy priced well designed footers for your 'table, and you will be rewarded with better performance. 

Most turntable manufactures were aware of excessive capacitance in tonearm cables causing issues so they used low capacitance cabling for the tonearm. Today there is better and it can be purchased fairly cheaply. Look inside and see if you are up to replacing them yourself.
If so the easiest route to getting a quality cable replacement is to contact the BlueJeans cable company and have them make a set of cables with RCA connectors on one end and have them strip the other end so they can be soldered on. They can sell you very high quality cable for little money. All of the cable specs are on there website, no voodoo magic, just sound engineering.
As far as the power cable unless it's damaged I would leave it alone. It only draws 7 watts of power. Or about 60 milliamps. Some fancy powercord may look neat but it will make absolutely no difference unless you imagine it to.

BillWojo

I still have one of those, mine's a 75 Technics but same thing, hardwired and absolute crap. Between the IC and power cord its tough to say which is worse. These are not at all matched to the table. They are nothing more than a cheap wire with the absolute minimum conductivity to get recognizable music out of there. 

They are in no way matched to the table. The table itself has nothing to do with it. The cartridge/cable interaction is what drives sound quality, and they never made any of them for any specific cartridge so you can forget about that. Any decent aftermarket wires will be a big improvement well worth the effort.  

What I would do is first of all open the table and have a look to be sure this is something you can do. While you're at it you should at least look at the power cord. I've actually done this stuff by the way. Replaced the hard-wired power cord on a motor. Definitely will hear improvement, even with a very budge priced wire.  

While in there be sure to check the bearing. I sure hope after all these years you have at least lubed it a couple times. If it can be opened, cleaned and lubed then do that. At the very least put a few drops of oil on it.  

Then shop around for as good a used interconnect and power cord as you can find. Do your best to ignore the well-meaning types who will tell you to DIY your own. They think they can do better than professionals. They are so misguided they don't even know. Besides when they are years old there are some really, really good wires that are dirt cheap. If all you spend is $75 or $100 each you will be shocked at the improvement.  

Then just remove the appropriate end, unsolder the wire and solder in place. Pay attention to details like how the IC connections are made. If you get noise when done it will almost certainly be due to missing something here. Good solder joints with no exposed wire and you should be fine.  

This is a totally worthy project. My first table was the Technics SL1700 and that one wasn't ever really modded. But my next one Basis 2005 the motor power cord was modded just like this, a literally $75 power cord was a big improvement over the rubber power cord Basis put on this $2500 table. So imagine the difference on yours from the flimsy Pioneer cord. Not to mention the patch cord. Yikes! I can see it now! Shudder! 

Go for it! Any questions feel free to DM millercarbon any time.