ADA4622 Stability

Hi.  I'm using an ADA4622 opamp with +/-12v power for a 1Hz to 40kHz preamp feeding an Apex PA78 power amp (see schematic below).  I'm seeing large and quite frequent noise spikes at the preamp output, unless I have a small load capacitance (including my scope probe) across the 2k ohm load resistor.  LTSpice simulation shows no anomalies... I'm starting to question stability of the opamp.  Has anyone seen this before?  Anything wrong in my schematic?

Thanks in advance.

Dave