Can a Headline be used with a Superuniti

Docoff, you can't really use a Headline with the Superuniti - at least not easily or the way it was mean't be used - mainly because there's no tape out.  You only have a variable pre-out on a DIN4.  It might be possible to use that if you make up some sort of DIN4-DIN5 adaptor but you'll still be juggling two volume controls, which is less than ideal for both convenience or performance.

p.s. Of course, I'm sure you know that the Superuniti has its own onboard headphone amp, but just to be sure...

I used a Headline with my SU for a couple of years.  I had a model that had the captive lead removed and a DIN5 input installed by AVOptions in the US.  I was also told by a dealer at the time that the DIN5 captive lead can be reterminated as DIN4 or there was a version of Headline with captive RCA leads.

I just ran a lavender DIN4 to DIN5 cable and when I wanted to listen to headphones I switched the internal amp setting to external.  I was told by Naim support that “65” on the volume control was unity gain and then simply use the control on the HL.

The SU/HL/NAPSC combo with Focal Elears sounded great and a significant step above the relatively poor headphone amp built into the SU.