[ckocagil]

Potential replacements for ultra low THD would be: OPA1612, OPA1656 and OPA1642 with bipolar, cmos and jfet inputs respectively.

[magic_smoke_ee]

There's a massive (old) list of them in Horowitz & Hill TAOE 3e Table 8.3a p. 522. I'm sure you can just go to Digikey or Octopart and do a parameter search for high-voltage, low-noise, BJT-input op-amps too. If one wanted to "use a Ferrari to go the grocery store", they could always use a $20 AD797 or LT1115 for audio applications. :o)

[ckocagil]

I picked those particular chips is due to their extremely good performance at a reasonable cost. Check their THD against AD797 and LT1115! :)