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

@kennesawjet I had pretty much all AZ cables including Wow and all the way up to Absolute Copper. As you go up the line you get a noticeable improvement in clarity, resolution and soundstage while retaining the warm sound signature. One of the best combos and values is the pairing of Silver Ref II and Matrix Ref II. As to the ARC preamps, I’ve never heard one that sounded unnatural or mechanical and I had the following preamps in my system: LS15, LS16, LS25, Ref1 and Ref6. 

These were paired with various amps and speakers starting with DNA-0.5, DNA-125, DNA-225, Pass X250.5, Pass X260.8 (with Ref6). Not trying to convince you but your statement about ARC sound is a bit unusual and inaccurate in my opinion. Keep in mind, you have to have all your components on the level. These preamps are revealing and will show you what’s up and down stream. It’s likely that either the source, the amp or thd speakers you heard with ARC preamps were not up to par. A low quality digital source will make itself known thru a transparent preamp like the ones I mentioned above. So perhaps that’s what you heard…just a speculation…since we hear things differently. Your system, your ears, your room. 

+1 @audphile1 You might try waiting for a suitable used AZ Silver Ref interconnect to come available (I’ve got a couple pair but won’t part with them) and try that in place of the Wow and see what happens, and it’s also the cheapest and easiest thing to try. If it provides an improvement in the right direction you’re probably onto something, and adding more Silver Refs will give you even more as in my experience their qualities are cumulative.  I’ve used the Silver Refs with my McCormack 0.5 for many years and find them to be a very synergistic match and provide precisely the sound characteristics you’re looking for.  I can only imagine they’d be a big improvement over the Wows. 

@kennesawjet I am not familiar with your particular preamp and couldn't locate any information googling herron v1. 

If it is a tube preamp you know their tubes often loose fidelity slowly over time.  If it is a tube pre and you haven't changed tubes in a while I think it may make a marked difference for the better.  If by chance it uses 12ax7, as mine does, you might consider trying 5751 tubes in the line stage (not phono stage). GE 5751 black plate triple mica tubes are affordable and very good.

Of course if your preamp is SS, forget the above.