What is a good turntable preamp under $500?

If you want to run a test without risking much, pick something within your budget from Music Direct. It has a 60-day return policy for full refund. Several of the units mentioned here are available there.

IFi Zen phono with the optional ipowerx power supply. 

Lounge Audio's LCR MK III.

If your intention is simply to get the rig up and running, purchase an old Radio Shack Phono Preamp. They are not screechy like the modern units and can be had for low $. Leave it plugged in for a week or so before judging as they are roughly 40+ years old at this point. 

The Schiit Mani2 phono preamp- Fremer gave it a very positive review:

https://www.analogplanet.com/content/schiits-mani-2-mmmc-phono-preamp-goes-head-budget-phono-preamp-class-0

Schiit makes high value components consistently performing above their price point.   At $150, this looks like a bargain.

Schiit’s website still shows the Mani and not the Mani2, but per Schiit after ordering:  ”To answer your questions, yes you will be receiving the Mani2 since Mani V1 is no longer available since it's been discontinued. ”

Yes, I meant to type MM. The Grado is a low level cartridge, I think it is called Prestige Black. Again, I know this equipment is considered lo-fi, but my original intention was just to see if I could get my turntable up and running. I have a Classe SSP in my main rig, but it only has one analog input, which I am using for my Lumin streamer. Hence the reason I am using the Pioneer receiver in a second configuration for the turntable. I have no intention of trying to get to the level of my digital system, but was hoping to find out the first step to improve it ( turntable, cartridge, or preamp).

So much bad advice it truly boggles the mind. Unless you upgrade from the Pioneer Elite you will spend money spinning your wheels. What Grado MM, I assume, (you wrote "nm") cartridge and stylus are you using? It has to start there. The Yamaha tt may not be awful but the cartridge determines everything, even if you keep the Pioneer Elite for the time.

Replace the TT and keep the phono preamp for now.

Take a look @ Grislybutter's new thread for a TT pretty much in your price range.

DeKay

Those Regas are not great values in my opinion.  The Pro-Ject Debut EVO is the pick of the litter for $600.00.  Your CA preamp will serve adequately...it's probably a $200.00 item.  The PF-20 is a toy, but better than any Garrard idler drive mass market 'table. The Rainier on the EVO will be better than the Grado, too.  If you want a new preamp, nothing will beat the Mani 2 for the $$$.  You seem to be budget constrained, so hitting the peak value quotient is essential.

What do you think of their intro model, the Planar 1and  the Planar 1 plus, which has. Built in preamp?

Go Rega, any model.   Just read the reviews. 

ah so sorry…..It is a Yamaha PF 20.  I don’t know why I thought it was a Gerrard.  I did have a Gerrard at one point in my life.

What model is the TT?

DeKay

Yes, upgrade TT first. Then get a equally expensive phono preamp (or an newer integrated amp with phono stage). Throwing $500 at just a new phono preamp probably will keep you wondering/expecting more.

Original OP question: get a used "ifi phono2". I have one and love it, very configurable for different cartridges.

Yes, the turntable is very old.  So, based on crustcoot’s comment, would I be better off getting an upgraded turntable first before upgrading the preamp?  I have been all digital for many, many years and my turntable is from the Stone Age😁.  Just want to get a decent analog system for a second system.

Rega FONO, in either MM or MC flavors (MC is slightly over your budget, MM is well under).

Hagerman cornet I, II, III used if possible and the biggest deal is the bugle

Hello?  Garrard is not a name associated with quality turntables unless you have a pro transcription model, which I doubt. Your CA preamp is MUCH closer to the best available than any Garrard mass market player. For $500.00 get a decent turntable, put your Grado on it and see what you have. 

+2 for the Bellari.  The headphone section performs very well to boot.

add parks audio budgie to tube list. never heard it. everyone luvs it

solid state:

darlington labs mm-6

ifi zen
newesst schiit mani-suppsedly it got better

solid state just over $500

audio by van alstine vision q phono

darlington labs MP-7

tube, including used:

pro-ject tube box s2,  under-$500 w/o/ tax, at least when i bought it, tho its prolly more now. goddam its real  good. 

heind ear 834p clone, $30o shipped w/o tubes
hagerman coronet 3
bottlehead moreplay

+1 for the Bellari VP130! Add a real Mullard or Telefunken 12AX7/ECC83 and you'll have a killer phonostage!

I would upgrade from a Pioneer receiver or save up for better speakers perhaps before spending money on a phono stage, but if that's where you want to put your money the Parks Puffin would be my recommendation at your stated budget. 

Darlington Labs MM-6 is all discrete and has zero negative feedback.

Phono stages get dramatically better with cost. You will probably find a $500 Phono stage better. I have been unhappy with low cost phono stages.
 

You can get surprisingly good sound out of a few thousands of dollars of analog. I typically recommend the investment in the phonostage roughly equal the TT.  I had an old AR turntable which I was finally able to put in next to my contemporary TT (through a $17K Phonostage)… it sounded terrible. There has been huge improvements in TT over the last 30 or 40 years. 
 

For the last few years I have been playing the game of having analog and digital neck and neck. Digital was better until my most recent upgrade, where vinyl moved ahead a bit. Both are totally satisfying. You can see my system. 
 

Just some random thoughts. 

Pro-Ject Tube Box S2, add some good aftermarket 12AX7 tubes. 

Yes, a Grado NM cartridge 

This

https://www.dagogo.com/jasmine-lp2-0-se-phono-preamplifier-review/

Here ya go!

 Bellari - VP130 Mk2 Tube Phono Preamplifier - Music Direct

What cartridge? I assume MM…

Choices under $500….just to call out a few

MoFi StudioPhono

Parasound Z Phono

Schiit Mani

Check out Hagerman phono stages.

Parks Puffin