Why not to use two pnp or npn as current source ? You can adjust current by changing resistor , voltage linited by transistors you use, with 2n5401/5551 plenty of voltage. Only disadvantage is that it needs three wires, but i saw two wires version too.
You may find those legendary articles helpful in understanding why JFET CCS is better:
https://audioxpress.com/assets/upload/files/Sources_101_P1.pdf
https://audioxpress.com/assets/upload/files/Sources_101_P2.pdf
It is not only CCS impedance or PSRR in question. BJT sources have considerable current/temperature dependency. JFETs are not immune either but I find that J113 CCS at 4-5 mA and 12-15 V Vds is almost temperature independent.
https://audioxpress.com/assets/upload/files/Sources_101_P1.pdf
https://audioxpress.com/assets/upload/files/Sources_101_P2.pdf
It is not only CCS impedance or PSRR in question. BJT sources have considerable current/temperature dependency. JFETs are not immune either but I find that J113 CCS at 4-5 mA and 12-15 V Vds is almost temperature independent.
in this tread https://www.diyaudio.com/community/threads/lsk-pre-baf-2013.244106/post-6619509
juma likes the LM317l
juma likes the LM317l