Enquiries should be made into the debilitating effects of playing gigs in stadiums. In clubs, Faithless are one of the most fearsome live acts around. In a vast but half-full ice rink they are lost in space. When the normally ice-cool Sister Bliss is reduced to stabbing dramatically at her keyboards (the equivalent of the 1980s rock guitarist's facial contortions), there is clearly something wrong.

In large venues, you simply can't do the same show that works brilliantly in a club. Stadiums demand bigger choruses, bigger chords and big but empty gestures aimed at the bloke in row Z who has dropped his burger. If you are Bryan Adams or Bon Jovi, this comes naturally. If you are a socially aware dance act whose music has always sought to balance euphoric beats with subtlety, it doesn't.

These sort of events demand a show, but Faithless make do with a handful of strobes and a projected backdrop. Musically, they have spoiled their best songs by trying to adapt them. There are longer middle eights, Simple Minds-style trance and horrible Joe Satriani guitar solos. The bigger dance numbers - God Is a DJ, Insomnia and Tarantula - suit the occasion, but they are mystifyingly outnumbered by slower grooves. When a visibly nervous Zoe Dickson steps up to sing the wistful Crazy English Summers, her voice is rendered cruelly metallic.

In the soulless void, Maxi Jazz emerges as a beacon of humanity. He smiles, which may even be spontaneous. His bleak homelessness rap Bring My Family Back survives unscathed. However, coaxing the crowd to raise one finger during unity anthem We Come 1 is a gesture so crass even Jim Kerr would give it the middle finger.

On the most basic level, an hour and 20 minutes for £20 is shocking value for money. Perhaps Faithless realise the mistake of abandoning their natural habitat, and have dashed off to find a club.

· Faithless play Plymouth Pavilions (01752 229922) tonight, then tour.