Hi Andreas,

I don't know when M changed from using the UMEC PSU to the XP POWER ECM40UT31 PSU but if you've already got the hood off your G68 then the easiest way to tell is to compare your PSU against those shown in the Wiki (Internal Pictures) for G68 and 861 - they both use the same PSUs although the 861 has more sophisticated post PSU regulation. Follow this link and scroll down to the 3rd picture down to see the old type (and again at the 14th picture down), scroll to the 15th picture down for the newer type:

http://www.Meridian-audio.info/viewphoto.php?compid=51

The cage for the UMEC is larger than the one used for the XP and bears the Meridian Boothroyd Stuart logo in two places. The newer PSU is smaller without any logo - unless of course you're looking at my G68 which has the old cage with a later PSU inside it ;-)

To be absolutely sure you can tell by looking at the position of the blue and yellow wires which lead from a connector on the PSU to the motherboard. If they are next to each other then you have the newer XP PSU. If they are at opposite ends of the connector block with 2 red and 2 black wires in between them then you have the earlier UMEC supply. Pictures 3 and 15 show the wire positions very clearly.

The position of the wires going from the PSU to the motherboard really is most important - get it wrong and you'll feed the wrong voltage to the motherboard which will have dire consequences!

Main: 861v8+ID41, 218, HD621, DSP8000SE u, DSP7200SE u, DSP7200HCSE u, Oppo BDP103D, LG OLED557BV.
Second: 218, DSP3200, DSW.
Other Rooms: 1) F80 + MS200. 2) F80 + MS200, 3) F80 + R Pi. 4) F80 + R Pi, 5) F80 + R Pi
Vintage: 207 CD Pro, Lecson AC1 + FM1 + AP3 MkII, Quad ESL 57s