Again on the tougher side today. Actually went down for breakfast after seeing 18A and completed this after breakfast :-) When I solved it some weeks ago.
ACROSS
1 Minstrel with instrument entertaining king, old and gloomy (10) TROUBADOUR {T{R}{O}UBA}{DOUR}
6 Perch for member of male voice choir (4) BASS [DD]
10 Beams, having last bit of summer pudding (7) RAFTERS {
11 Fantastic day, none getting fed up (7) ANNOYED*
12 Checks acts designed to get publicity (6) STUNTS [DD]
13 Work concerning small car (8) RUNABOUT {RUN}{ABOUT}
15 Theologian, until converted by article, right behind revolutionary force (6,6) MARTIN LUTHER {RAM<=}{UNTIL*}{THE}{R}
21 Enter without permission, using pressure when breaking lock (8) TRESPASS {TRES{P}{AS}S}
22 Area in good order around university hall (6) ATRIUM {A}{TRI{U}M}
24 Criticise expert with a remedy (7) PANACEA {PAN}{ACE}{A}
25 Opening home with key, not against letting one in (7) INITIAL {IN}{
26 Brute with book out to make a point (4) EAST
27 Live with desires for possessions (10) BELONGINGS {BE}{LONGINGS}
DOWN
1 Wearing fresh rose in season (8) TIRESOME {TI{ROSE*}ME}
2 Unprepared, not operating with screen (3,5) OFF GUARD {OFF} {GUARD}
3 Pause, having broadcast bare facts with rapidity (9,5) BREATHING SPACE {BARE*}{THINGS}{PACE}
4 Deer receiving small quantity of medicine (4) DOSE {DO{S}E}
5 In difficulty? Meet guru, unusually enthralling old man (2,1,3,4) UP A GUM TREE {PA} in {MEET+GURU}*
7 Hospital in no way working carelessly (6) ANYHOW {H} in {NO+WAY}*
8 Calm lawyer on time in spot (6) SEDATE {SE{DA}{T}E}
9 Call after battle for sign of promise to unite (10,4) ENGAGEMENT RING {ENGAGEMENT} {RING}
14 Fail to keep quiet in underground chamber, making narrow escape (5,5) CLOSE SHAVE {C{LOSE} {SH}AVE}
16 Inspector with dream department (8) DIVISION {DI}{VISION}
17 Stubborn type, endlessly engaged in legal actions, raised motivation (8) STIMULUS {MUL
19 Fastener's main element (6) STAPLE [DD]
20 Misbehave and catch up in game (6) TENNIS {SIN}{NET}<=
23 Floor covering useful in our houses (4) LINO [T]
GRID

