Looks like you’re right, Fabiola. According to an article on Wikipedia:
“As in English, voiceless stops are aspirated (articulated with a puff of air immediately upon release) at the start of a word, while voiced stops may be incompletely voiced but are never aspirated. Voiceless stops are unaspirated after /sË / and /Êƒ/ (e.g. scanradh [sË kauÉ¾Ë É™] “terror”); however, stops remain aspirated after the clitic is /sË / (e.g. is cam [sË kÊ°aum] “it’s crooked”) (Breatnach 1947:33, 76). Several researchers (e.g. Ó Cuív 1944, Wagner 1959, de Bhaldraithe 1966, Mhac an Fhailigh 1968, Ó Sé 2000) use transcriptions like /sb sd sÉ¡ xd/, etc., indicating they consider the stops that occur after voiceless fricatives to be devoiced allophones of the voiced stops rather than unaspirated allophones of the voiceless stops, but this is a minority view.”
However, I would still say that aspiration is considerably stronger in English. Check for instance the pronunciation of “tasc” on the http://www.focloir.ie web site. It doesn’t sound like “task” in English…
Perhaps Lughaidh and others can expand on that.