Way before my time. I would have to look through dusty schematics in service.
I know Nait 1 does not have an output resistor but does have a Zobel; I was listening to one recently 
If you have a specific vintage amp (chrome bumper) I can go to service and look at schematics. Iām away currently.
As a general rule, chrome bumper is most sensitive - as per manuals. Olive is more tolerant but take care. Triptych (circa 2002) is very good, DR is excellent as is new classic.