LKS 004 or monarchyM24 dac?

I own the LKS dac and Had it modified by Rick Schultz and place them on symposium 
Rollerblocks. Excellent dac Happy turkey day

I have used a Monarchy M24 in my system for close to a decade and love it. Recently, I replaced the WIMA coupling caps with some Mundorf Gold/Silver/Oil and this was a worthwhile upgrade. Tube rolling is also worthwhile but you don't have to spend much money to get great performance (my current favorite is the JJ Gold Pin).

As I'm sure you know, the Monarchy is a ladder DAC based on the Burr Brown PCM63 chip which is considered by many to be the best chip of its type ever produced. The LKS uses the ESS9038 chip and is a delta-sigma DAC. Some, like myself, prefer the sound of ladder DACs and others prefer delta sigma. I am biased, of course, but my choice would definitely be the Monarchy. 

One thing to note about the Monarchy is that it will not play anything higher than 20/96. If you must have higher resolution or DSD, pick the LKS. 

I have an NM24 DAC. Almost a year and a half ago I installed new tubes and replaced the two output coupling caps with Mundorf Supreme Silver Oil caps. The fresh tubes made a welcome difference immediately, as the installed tubes clearly were tired. Then about  three months ago I noticed the Mundorf caps beginning to blossom into their own. It has taken probably 200 hours of use over the past year for the caps to break in. And the resulting sound is absolutely wonderful, sweet, meaty, harmonically rich and complex, more timbrally accurate, and more real and “in the room.” The difference is astounding. If I could have a do-over, I would play the DAC with the old tubes for two weeks ‘round the clock to let the caps break in.

My DAC also happily sits on an FIM rollerblock stand, which is no longer available, but which is, I believe, similar to the Symposium stand. 

So +1 for everything the previous posters stated. I am not familiar with the LKS unit. I am certain you will like the Monarchy though, especially with the Mundorf caps. In my experience a very good PC and interconnects make audible improvements as well.

My digital player/ streamer is set up to convert 192/176 files and higher to 96/88. Invariably the higher sampling rates are audibly superior to, say, 44.1/16 bit files heard through the Monarchy.

Hope this helps. Best of luck whichever way you decide to go.

There is a newer LKS 005 now.