Yes, another audiophile at a crossroads story and request for advice

SPDIF cable is not high or mid end based on recommendation of the customer technical support person i purchased from. He said it was a waste of money to spend more  there. 

It sounds like you have done your homework on the DAC and it is to your liking. I will disagree with your technical support person regarding the digital cable. While not a solution to all of your problems, I highly recommend you do some research and try going up the chain a bit there. My system improved when I upgraded this cable.

One follow up question, when you listen to jazz on your vinyl setup, do you hear more of the sound you are looking for?

I am going to throw this out there, it seems like your system is solid for what you are using it for. Have you thought about replacing your current speakers and opting for a NOS set of tubes in your Integrated and dac? I have been back and forth with SET systems and regular push/pull tube systems and I loved the texture I was getting with my Klipsch Forte IV’s with my 45,2a3 & 300b amps but I ended up missing that extra headroom from higher powered amplifiers. I used a Audiomat 30w integrated with my Forte IV’s and loved the extra oomph and used that as a place keeper until my what I call my Super Quad ESL 57’s were being created by Kent at Electrostatic Solutions in KC(Robin Wyatt YouTube video for reference). I only mention the Quads as my other pair of ESL 57’s sound exceptional with the Audiomat EL34 tube amp. I used my Audiomat with Holland metal based EL34’s and 62’ Mullard 12ax7’s and it was everything you are looking for in sound. I am done with my search with the exception of a DAC as I miss my Wavelength Cosecant N2 dac.

My current setup:

Herron Audio 360 ESP Reference

McIntosh MC75 original issue with GEC KT88 NOS and Telefunken driver tubes.

432EVO Aeon Streamer/Roon Core

Rockna Wavelight Dac

Herron VTSP-2a phono preamp

STS Thorens TD-124 with Jelco 850L and Ortofon TA-110 Tonearms

Koestsu Urishi Black and Haniwa HCTR-01 Mki MC cartridges

Solid tech rack and Still Points ESS rack

cables are Western Electric speaker wire and Herron Audio Interconnects

Good Luck!!!

@wolf_garcia I’ve read good reviews and your positive comments regarding use of the Loki to sculpt the sound to taste is an interesting idea. My RME DAC has a graphic equalizer feature that I’ve not yet used or explored. I’ve been reticent to try it, but I should check it out before changing out any hardware. 
@zlone I got into jazz about 15 years ago, all my records were bought ~ 10 to 15 years before that so all my jazz physical media is on CD. If my no cost experiment of engaging the equalizer in my DAC doesn’t provide the sound i’m searching for then I’ll try a higher quality SPDIF cable. Do you have one you would recommend for my current system and sound goals?

@ezstreams that's the hard part to suggest, I think, since there are so many possible combinations of gear, tubes, peoples listening perceptions, etc.  

For me, I just kept a notebook and marked down how each combination sounded so I could refer back to it.  This is especially handy when swapping out speakers to help get the right combination.

You could just try ordering some different sets to see what works.  Another thing I ran into was that just because a tube is more expensive, doesn't make it a better performer in a given application.  Sometimes, a cheap tube can sound great, just as an expensive tube.

A DAC with a graphic EQ? Who knew? The Loki Max is a deluxe EQ unlike anything else out there (in the analog world anyway).