Any hopes of pulling back a first leg deficit of 18 points were dashed as Edinburgh took a six-point advantage from the first two heats at the St Boniface Arena.
The Devils team manager Lee Trigger said: “It was disappointing to go out of the cup, but it proved to be a good meeting with a good battling performance by our riders.”
Plymouth fought back midway through the meeting with a couple of 5-1 heat wins by Jack Holder and Todd Kurtz in heat nine and Ben Barker and Stefan Nielsen in heat 10. But Edinburgh hit back with a 5-1 in heat 11 and, from that stage, Plymouth’s realistic target was a win on the night.
Barker, guesting for Charlie Gjedde, scored 10 points for the Devils with Holder also in double figures. Reserve Nielsen had another impressive evening with nine (paid 10) from his seven rides.
But the Devils could not match Edinburgh’s Sam Masters who ensured the Scottish side’s cup progress with a 15-point maximum.
Plymouth: Ben Barker 10 (5 rides), rider replacement for Kyle Newman, Jack Holder 12+1 (5), Todd Kurtz 8+2 (5), Sam Simota 6 (5). Reserves: Stefan Nielsen 9+1 (7), Ellis Perks 2 (3).
Edinburgh: Sam Masters 15 (5), Erik Riss 7+2 (5), Kevin Wolbert 7 (4), Jye Etheridge 0 (4), Ryan Fisher 4 (4). Reserves: Max Clegg 8+1 (5), Dan Greenwood 1 (3).