Has anybody come accross discrete opamp implementations for sale online (such as the Welborne labs or Johnhardyco units) as replacements for monolithic units and has anyone used them or compared them with monolithic opamps?
Some of the best discrete OPamps out there are the ones made
by Forssell Technologies! Forssell
I have both the DLR-1 and the JFET-993 and they sound great! The 993 can be used with 600 Ohms, and the DLR-1 is made
for higher resistance loads (>1k). The DLR-1 sounds a bit better. It is almost as good as Borbely's Superbuffer1!!!
They are all pure class A, and made up out of JFETs and some very good SMD resistors (Tantalum nitride).
This is how I have evaluated the 993 and the DLR-1 (I have used sockets for the pins so I can interchange between the DLR-1 and the 993 - I just pull them straight up like pulling out an DIP OPamp from an IC socket).
Caddock MK132 resistors, MICA cap for the feedback resistor, ELNA Cerafine 47u cap and WIMA FKP-3 0.1u.
Silver wire for the signal path.