Power to an 80’s DSM8+ analog drum modules

[talkboxert]

Hi there, I am trying to power my DSM 8+ which way originally powered (and also could receive accent I think) over 5 pin Din by the master drum module I think the DSM1/2 .

I bought this power supply: https://nl.mouser.com/datasheet/2/260/G ... 291644.pdf it has din but the pinout is not right (see pinout/colour codes on page 4)
I just cut the Din plug of than connected white (-15/0.3A) to black, black to blue and yellow (+15/0.8A) rerouting the pins as follows:

Pin 1 - -15v
Pin 2 - Ground
Pin 3 - +15v

This is the info I got from Clive who was involved in the original design back in the day.

When I powered up the module both + and - lights came up, so I was quite happy. However 1 problem is the sound seems to be triggered almost at audio frequency. The trigger input triggers the pitch eg etc, I hear the drum voice changing as I tweak, but everything is overshadowed by this low rumble of soft triggers, that keeps the "trig light" kind of flickering all the time. So some interference channel reaches the trigger input it seems.

Possible solutions:

-The PSU doesn't have the right specs +/-15V at 0.8 and 0.3 a respectively.
- I left the outer shielding wire that surrounds the 5 coloured cables unconnected thinking it does nothing, maybe connecting this provides a solution?
- I confuse COM with ground in this instance, the mean well PSU has no ground on the 220v end.
- I wired it up wrong and the accent input revceives a voltage from somewhere? Seems unlikely since + and - seem to be in the right place since both lights come on.

Any help is much appreciated,