Tubes/name top 5 units

My setup is based on this concept of great sound under a certain cost. Stated out with a $4000 limit. 

Once you get into it, the desire to improve the sound will make you desire better and cooler equipment. Stereo "porn creep" so to speak

My gear
Furman Line conditioner $150
Project Carbon Turntable $1000
Ortofon Blue Cartridge $350
Onkyo CD player $500
Audioengine B2 streamer/DAC $200
Cayin Audio tube amp 40 watts $2000
Tube upgrades $600
Monitor Audio Siver 500 speakers $3000
misc. wires & interconnects $200
this is the first time I ever added it up. $8000

a lot of posters on this site have spent many, many multiples of this.

Im really happy with my system. I am going to leave alone "for Now".

My Grandma's old RCA tv had tubes.I remember going with my Uncle to the local drug store they had a tube testing stand ,which was filled with tubes. I also worked in a whole sale electronic warehouse and I was a inventory clerk and I had to do the inventory on the tubes we carried back then...General Electric, RCA ,Westinghouse no foreign tubes back then ...funny .

Cayin Audio tube amp 40 watts $2000

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Hey
Big Cayin fan here

which Cayin do you have...
Let me guess Cayin 45 with EL34 and ,,which pre tubes??