Who are the most underground high-end companies

a couple more..

Music Reference
Theta

Kyocera. I believe they got there start in the marine industry. Still a player in the semiconductor sector. I remember their TTs, amps, preamps.

octec11: Some well known designer was involved with Perreaux, was it Nelson Pass? Can't remember.

Verastarr Cables, boutique cables at real world prices.  

"The brick-and-mortar shops raks 50 percent off the top"

deepee99, you're spot on with that assessment. I have not paid retail on anything in over 10 years.  It's quite appalling to see the ridiculous pricing in high end audio. It's seems to me some of the manufacturers are more focus on audio jewelry than the art of music.  

i've a few for you Taters:
Selah Audio in NC - you hear a little about them now & then. They make very good sound line-array speakers & the owner is a very good person to talk to.
Moon Audio - Drew Baird runs this operation from Raleigh/Durham area. Very good & cost effective cables (atlas they used to be inexpensive. Don't know if he's raised his prices a lot)
Green Mountain Audio in Colorado Springs - my favorite cone-driver speaker manuf. I've owned his speakers & my brother still does. Like someone wrote earlier. I'm not on his payroll - just an enthusiastic supporter of his really good sounding speakers, One of the very few speakers that are time-coherent, which is the only way to go.
K & K Audio - which is run by Kevin Carter. His best selling product has been his phono stage. Very little spoken about him though he does have a forum over on Audio Asylum. Really nice fellow to deal with - calls a spade, a spade & very knowledgable. 

a few auto-correct typos - please excuse.

good to see that a few others mentioned Green Mtn Audio - I 2nd.

Also, 2nd Scott Nixon - I’ve his non-oversampling DAC in my bedroom system that uses the Philips TDA1541/43 chipset. Excellent sonics. I think that he still makes new tube DACs.