Hello,
I found that the circuit of a non-budget headphone amp Felix Envy (7000 usd) is the same. I have little knowledge about tube circuitries, but can you tell me what output transformer is needed for heaphones with impedance 300-600 ohm? Do I need any changes in the circuit to operate the amplifier for high impedance headphones except for the output transformer?
I'm not a headphone user so have very little experience with them but you normally want the secondary impedance to match the load. Not sure you need a 300B tube to drive a pair of headphones. Like how many watts of power do headphones need? At some point I probably need to do a headphone amp build with a low power tube and some output transformers like these https://edcorusa.com/products/gxse5-5k-5w-5k-ohms-single-ended-tube-output-transformer?_pos=2&_fid=a2965e667&_ss=c