272 and old hicap?

No, a 272 needs an XP5XS, XPS or 555.

The 272 gets its external power upgrade via a Burndy and therefore as Chris said it needs an XP5XS, XPS or 555. 

It's just as Chrissu & Finkfan say above, wonderful as a Hicap is, it just doesn't fit the 272.

It's my experience though that the 272 performs very well indeed in its 'naked' state, just as it comes out of the box.  I've been using one recently to replace a NAC552 - I've been getting random clicks & pops from my speakers and have been trying to pin it down to the preamp, hence the swap.  The 272, as I said, is an extremely good performer in these circumstances.  I can only imagine that it would blow your thingys off when powered with an XPS or 555PS.

I hope you manage to find an external power supply for your 272, but aim for the XPS would be my advice 

ChrisSU posted:

No, a 272 needs an XP5XS, XPS or 555.

Just like it says on Naim’s website. Who would have thought it?

It's interesting to note that many manufacturers only talk about their current and recent things on their website, so not seeing a 30 year old hicap doesn't actually mean that much.  But obviously you know naim better and know that everything they ever write is correct.  That's why everyone buys focal speakers now, clearly..... :-)