How to identify NAC72 boards

[chris5]

I may be a little biased but think I have a really nice NAC72, that looks to have a full set of boards in it. I’m struggling a little to identify just what they all are though, can anyone please point me to a reliable source of info or does anyone know what they are without looking them up?

Thanks, in advance, for any pointers

[Richard.Dane]

The FAQ here should help;

Naim NA3xx and NA5xx Pre-amplifier daughter boards

Earlier Naim pre-amplifiers used interchangeable daughter boards. While the very earliest NAC12s did not use daughter boards, most were updated, and the early versions of the NAC12 and NAC22 used NA1xx and NA2xx boards that used knife edge connectors but were superseded by pin mounted NA3xx boards. The NA3xx boards that can be found and used in later NAC12s are; NA325 - Switching Relay, switch-on output delay x 1 NA321 - Main gain, output drive x 2 NA324 - Input Buffers x 2 NA322 - MM …

[chris5]

perfect, thanks Richard

[Fatcat]

Looking at the capacitors, I’d say it’s been serviced.

[petermjames]

My 1978 NAC12 was converted to a 12S by changing the phono input boards from MM to MC.

[chris5]

good spot, 2014 was the last