what preamp goes best with mccormack dna 500, follow up....

I would absolutely look at the Backert Labs Rhumba Extreme preamp as being a great match for that amp.  Contrary to jafant's suggestion,  I would steer clear of c-j preamps - their output impedance curves are all over the place with changes in volume and the big McCormack works best with XLR inputs anyway.

You’ve got a very good amp and preamp.  Maybe try some tube rolling in the Herron to inject more sparkle and life into the sound?  Frankly, if I’m you I’m looking at the speakers.  Many newer speakers have more natural detail and better 3D imaging and a bigger soundstage with better overall transparency than speakers of yore.  As an example I’d mention these Joseph Audio Perspective 2s in their gorgeous Sapele wood finish that’ll likely expand your audio horizons in all directions.  If not, just sell them for little/no loss, but IMHO that’s the prime area for an upgrade given what you’re looking for.  Just my $0.02 FWIW, and best of luck.

https://www.usaudiomart.com/details/650009107-joseph-audio-perspective-2-graphene-original-not-upgraded/

blackbag 20   i cant afford that stuff

jafant thanks, knew you would chime in, i have a conrad johnson.....et3se

jwpstayman,  i was considering the xlr type amp

soix   thinking about selling off some of my stuff to get me one good preamp

kennesawjet

The CJ ET3SE is fine for an older pre-amp. If you enjoy the CJ house sound, there is plenty of room for upward mobility. Keep me posted.

Happy Listening!

Your weak links, in my opinion judging by the components list, are your source and interconnects (AZ Wow).
Heron is supposed to be a very nice preamp and DNA-500 is an awesome amp. I used to own DNA-225 and drove it with ARC LS-25 preamp and ARC CD3 cd player. If you want to pursue the preamp change, ARC should be on your list but again, I think you will end up in the same situation unless you upgrade your source and cables (in this order).