i use an F4 as my headphone amp, but i have hard to drive headphones. Best solid state amp ive heard with headphones. I also used an inline attenuator for headphones that werent so hard to drive.
You first have to change the LU1014 triode cell from 1.3A bias to 200mA.
See :
https://www.diyaudio.com/community/...l-fet-class-a-zgf-headphone-amplifier.225577/
Then you can simplify the Aleph current source with a single LM317HV :
https://www.diyaudio.com/community/threads/hybrid-zen-amplifier-lm317-efficient-and-simple.402477/
Of course you need to adjust resistor values to suit your requirements.
Best to simulate in Spice first.
No copy and paste.
Patrick
See :
https://www.diyaudio.com/community/...l-fet-class-a-zgf-headphone-amplifier.225577/
Then you can simplify the Aleph current source with a single LM317HV :
https://www.diyaudio.com/community/threads/hybrid-zen-amplifier-lm317-efficient-and-simple.402477/
Of course you need to adjust resistor values to suit your requirements.
Best to simulate in Spice first.
No copy and paste.
Patrick
This is a power amp for 4~8 ohm speakers.
I already told you how to change it for headphone in post #4.
First is to understand how the circuit works.
Patrick