The noise sounds as if it's coming from right in front of the driver when your in the drivers seat. To pin point the sound would be on the bulkhead, halfway down.
It is a light knocking sound and it does it every time you lift the throttle pedal, but it doesn't make it when out of gear or with the clutch dipped.
I know this sounds like it would be an engine mount or something making the noise from rocking when you let off, but i'm sure it isn't. It makes it in every gear even if you just rest your foot on the pedal then let it off, so even when no acceleration is applied. I've looked all over underneath and in the engine bay, everything seems rigid and tight.
I recently changed the clutch cabled and it may have got louder since, but that might just be me.
Anyway i'm hoping someone else has had the same noise before and can shed some light, your more than welcome to suggest ideas but I've probably looked at everything you'd suggest.