tube power amp for my thiels cs6 speakers

my present system includes cat sl-1 mk 3 preamp,krell ksa-200s power amp thiels cs 6 speakers shunyata orion speaker cables and krell kps 30 i cd player.any suggestions for tube amp under 5k including used ones? i do not listen at very loud levels-75 to 80 dbs sound pressure from my listening chair.

2.4 Ohms is tough load for tubes. There is a pair of VTL 450's for sale here that fit into your budget that might do. You might want to have a talk with VTL first.
Look for a Dynaco St-80 or St-160 by Panor. They have 2 ohm taps. The 160 is 80wpc and should easily handle your needs. The 80 may get mushy on dynamic peaks.
I have a pair of CS-6's and use VTL 300 Deluxe Mono Blocks which are fully upgraded. They do a darn nice job. I would go with the VTL 450's. The added juice would be a nice addition to great amps.

Good Luck
McIntosh MC275 has a two ohm tap. Rated at 75 watts a channel but it's more like 90 watts.

You can get them used on the GoN for $2300 to $2800 or better yet get two for 5K and use them in mono for 150 watts or 190 watts with upgraded NOS tubes.
those speakers are not made for tube amps.
As already mentioned the higher powered VTL's are a good choice also consider conrad-johnson, used Premier 12's or P 8's would work well. Their current models would work also but might not fit your budget. Good luck and happy listening!
I might also suggest a cj premier 140 used will be in your price range as will the premier 12's the 8a's will be a stretch. Tube amps and Thiels are very good together.