Iamnate, specifically to your question about using an outboard amp.
Basic question, how sensitive are your JBL speakers? Does the NAD under power them or are you wondering about a better quality amp section?
I've only used mine as a full integrated (and Nmmusicman's suggestion is likely a good one) but years ago there was an audio topic program on a LA FM station called "In Fidelity". The guy who hosted that used the preamp section of a 3020 with a Dyna St 70 to drive his Quad 57 speakers. Considering how revealing the Quads are it must have had good sonic qualities. Note here I'm not suggesting the St 70 for your situation. That would be a different question.
Basic question, how sensitive are your JBL speakers? Does the NAD under power them or are you wondering about a better quality amp section?
I've only used mine as a full integrated (and Nmmusicman's suggestion is likely a good one) but years ago there was an audio topic program on a LA FM station called "In Fidelity". The guy who hosted that used the preamp section of a 3020 with a Dyna St 70 to drive his Quad 57 speakers. Considering how revealing the Quads are it must have had good sonic qualities. Note here I'm not suggesting the St 70 for your situation. That would be a different question.