Top is 6F8G 6C8G. If want to try 6F8G 6C8G. Bottom is 6SN7 6SL7 CV181 6N8P 6H8C 5692 B65 ECC32 ECC33. Amplifier design use 6SN7 6SL7 CV181 6N8P 6H8C 5692 B65 ECC32 ECC33. Top ceramic socket with gold pin for long life.
eBay