Suggestions to upgrade from Lyra Delos

It appears that you have done some trials on "free" or near free set up modifications, many of which can have quite a big impact on the sound.  I hope you have tried changing vertical tracking angle; for example, lowering the arm pivot point will add bass weight to the sound.  I found that the Lyra cartridges I have used are quite sensitive to changes in vertical tracking angle.  I hope you have tried changes in loading as well.  With most tube phono stages, less loading than utilized with solid state phono stages tends to work out well (less loading means HIGHER value of resistance, such as 47k ohm). 

Not so free changes that will really make a difference involve the tubes used in your phono stage.  Telefunken 12AX7 and 12AU7 run the gamut from warm and smooth sounding to lean and very punchy and dynamic; it depends on the specific tube.  I run a lean and dynamic variant (ECC803S) that has become crazy expensive.  You could try other tubes that are known to be on the warmer side (that warmer side is often the "magic" attribute some seek in tube gear).  To me, a pretty safe recommendation that almost always seems to please are Amperex Bugle Boy tubes.

Given that the Delos is quite a nice cartridge, Raul's recommendation that you at least consider a phono stage upgrade is a reasonable suggestion.  I don't know about your Hagerman phono stage, but, I do know that a good phono stage makes quite a difference.  

@larryi 

Yes, I've adjusted VTA.  I have also played with loading and gain previously as well as after this most recent change.  Right now I'm running it at the lowest possible load and 60db gain.

I have tried a variety of tube complements in this preamp, and so far the Telefunken combination is the most 'natural' sounding without being overly colored.  The Mullard repros it came with are a waste of time.  I like the Telefunkens slightly more than the vintage Mullards.  I'm working on (because as you've said, it's not exactly 'free') sets of NOS Siemens, Bugle Boys and Vintage Raytheons.  I've actually ECC803s in this stage and it was a very weird sound signature - felt like the midrange was being thrown in my lap.

As I said, I'm looking into other phono preamps a notch or three above this one.  Sutherland, Herron, Musical Fidelity NuVista, and a few others.

But, I do think I've got this finally dialed in for the moment so I'm going to continue playing with it to see how it goes.

I do agree that ECC803S can have a forward, sort of aggressive, midrange (assuming you are talking about real, old stock, tubes); what is appropriate in one setting, or for a particular taste, is not appropriate in another.

I wish you the best in your search for a phono stage.  It can be a daunting task given how many candidates are out there.  I have not been in that market for a long time, so I have only run into different models incidentally.  I heard systems that sounded quite good with Audio Note (uk), Lector (Italy), Zanden (Japan), and Doshi phono stages.  I own a Viva (Italy) phono stage myself.  If you like to fiddle around with your sound, you would love the Zanden because it gives you a choice of equalization curves.  Sometimes, the "wrong" curve actually sounds better than the correct curve so it is nice to have that option.

Another option is to look for an outboard step up transformer to feed the MM input of your phono stage.  While I know there are all sorts of theoretical reasons for eschewing step up transformers, I've always preferred the sound of systems employing them (my Viva has a built-in step up transformer).  There are plenty to chose from, including custom-wound transformers made for your particular cartridge/application (look at myemia.com, a company noted for transformers and autoformers).
  

Didn't read whole thread but this caught my eye:

I've got it very low loaded and a decent amount of gain, so I don't think it's really the phono preamp

Reduce the loading to open up the sound.

@larryi - yes, I was talking about vintage/NOS tubes.  That's all I use.  I appreciate the suggestions, and I've been interested in the Vifa as well. I'll look into the Zanden, for sure. 

@noromance - yeah, I thought I was at the lowest load setting on the Hagerman and it turns out I wasn't. (It isn't obvious because the gain adjustment, which is built the same way doesn't operate the same way and neither are labeled or marked, so I had assumed that I was already at the lowest load based on knob positioning). That's what I meant earlier when I said I tweaked load as well. 

Again, it's definitely sounding better overall and on quality recordings it's sounding rich and full so, I think I have addressed short term issues.