Upgrade phono stage?


I am looking to make and upgrade an I think the weakest link is my phono stage. I listen mosly to blues, then rock, folk, jazz. The Zphono is not bad but i would like to get a bit more out of vinyl. Thanks.

My system is:
Primaluna PL2 w/kt88
Pro-ject Xpressions TT v1
Parasound Zphono
Triangle Comete es
Ortophon Super OM20
Shure V15VxMR stylus bent
Grado Gold love the sound

I have a budget of about $500 for used gear.
This is what I have been looking at but im open to any and all suggestions in my price range.. I am open on tube or SS. I would prefer mm/mc with adjustments as I would like to try a MC cart sometime.

Pro-ject Tube Box SE
Graham Slee
Jolida JD9a
Dynavector P-75
Wright WPP200C
grinnell
go with the wright, sweet sound, good value in the used market but plan on replacing the tubes.
the grado gold is solid, but an at150 will be a dramatic improvement...less than 300 bucks
I suspect your cartridges are the weak link. I haven't heard the Grado Gold, but if you are in love with the Grado sound, I had a Sonata, which was pretty good and would fit in your budget - you might even do better and get a used Master. I upgraded to the Statement Reference, which, even at $1200, was referred to as a "budget cartridge", which may help put your Gold in perspective.
to hear a big improvent over your z phono you will have to spend more than 5oo