A step up to 1400m for the first time since winning last season's Group One ATC Sires' Produce Stakes is expected to suit Godolphin-owned colt Microphone when he chases his first win as a three-year-old.

The James Cummings-trained Microphone is the early favourite for Saturday's Group Two Autumn Stakes at Caulfield dropping back to racing against his own age after finishing sixth in his return from a spell at The Valley in the weight-for-age Australia Stakes (1200m) against older horses on January 24.

The colt won four of his six starts as a two-year-old and was second in the Golden Slipper but he is yet to win in two starts this season.

Microphone was third in the Roman Consul Stakes at Randwick in his only appearance last spring before his connections scratched him from the Group One Coolmore Stud Stakes at Flemington because of an unsatisfactory result after a routine blood test.

Microphone had also been nominated for Saturday's Group One weight-for-age CF Orr Stakes (1400m) but will run in the Autumn Stakes, with multiple Group One winner Avilius to represent the stable in the Orr.

"Microphone's first-up run in the Australia Stakes was pleasing and he clearly demonstrated that he was looking for further," Cummings said.

"He got going again late and the 1400 metres here will be more suitable."

Microphone was runner-up to I Am Immortal in a Blue Diamond Preview in January last year in his only run at Caulfield and he got reacquanited with the course on Tuesday morning when he was taken there and galloped with stablemate Duca Valentinois, who runs in Saturday's Group Three Carylon Cup (1600m).

Under the set weights plus penalties conditions of the Autumn Stakes, Microphone carries top weight of 59.5kg in the field of 10 and was $3.90 favourite in an early market on Wednesday ahead of Banquo and Adelaide Ace at $4.80.