Responses from fixedincome

The best speaker cables you’ve had
Mogami 3103, homemade.  Replaced Analysis Plus Oval 9's which replaced everything else I have heard since the 1960's.  Outstanding speaker cables!  
Mixed Brand Pre-Amp Power Amp Pairings that Work
My Mark Levinson 380s matches very well with my AGD Audion Mono Blocks.  Sounds super with my Spatial Audio X5s.  Very neutral and revealing combination.    
Do you build anything for your high fidelity system? If so, what do you make?
A two shelf, equipment stand made from 1-3/4" "rustic" dark walnut.  60"X18"X21" tall.  Solid as a rock holding the TT, Phono-pre, CD Transport, DAC, Pre-amp, Mono-blocks, and AC Regenerator.  Lots of plaining and notching and doweling and sanding... 
recommended speaker cables and interconnects
Analysis Plus is the only manufacturer of cables that I use for Speaker, Interconnect and Power Cables.  I find them clean and neutral sounding, with no "house" sound.    
How do I get the best soundstage?
Get Jim Smith's book titled "Get Better Sound."  Read it, then sweat the small stuff.  
Denver and Front Range furniture maker -- just did my audio rack!
Very nice!  I'm building my own out of dark walnut.  A bit longer in my case to accommodate both analogue and digital front ends and mono blocks.  The wife insists on 5 inches clearance from the floor for cleaning.  
Spatial X5 speakers
I just passed the 500 hour mark on my X-5's and they are still changing for the better!  Stunning! I have them paired with AGD Audion mono blocks and a Mark Levinson 380s preamp.  Beautiful results.    
speaker choice for new 20x30 audio room
Spatial Audio X-3's would be my first choice. Dave  
Pairing Spatial Audio X-5's with ADG Audion Mono Blocks
I am approaching 450 hours of "break-in" time and "liquid" is a very good way to describe the sound!  The Bass is just recently reaching levels above and beyond what I have experienced with any other speaker.  Clear, tight and expressive, the dec... 
Products you added to your system in 2021 that made most impact to your music enjoyment
Spatial Audio X-5 Speakers made the biggest improvement. AGD Audion Mono Blocks came in second.  
Speakers for a Large Room (20’x37’)
+1 for the Spatial X Series. My room is 25'X25' with a cathredral ceiling topping out at about 14'.  The X-5's are stunning!  Detail retreval is like nothing I have ever heard.    
suggestions for a new stereo floor speakers
Loose the box and get a pair of Spatial Audio Lab speakers.  Stunning performance, real world pricing. 
What is the most important component to consider while building a new system?
What is the average life expectancy of a DAC?
My previous one lasted 15 years for me, and was used when I bought it.  It was a Chord DAC 64 
Mark Levinson - refurbish or start fresh
Pyramid Audio is where I had my ML 380s refurbished.  They are located in TX and are an "authorized" service shop.  Door to door including shipping time was a month.  Shipping, inspection, repair/refurbishment and return shipping was under $1,000....