Clark has been able to bring in eight players on a permanent basis, as well as Tottenham Hotspur defender Grant Hall on a season-long loan.
"If you include Matt Green and Jonathan Spector, you're looking at 23 senior players, which is terrific for the first day of pre-season training," said the Blues boss.
"Me and my staff identified the positions where we needed to bring players in and we're delighted with the ones that we've got. There were lots of other clubs in for these players but we managed to convince them to come to us when they saw the training facilities, the stadium and the support the club generates.
"By not relying on loans we know there's no worrying that if they do well they'll be recalled. It means we can have a more settled team and settled squad, although you can’t legislate for injuries."
Clark continued: "They are generally young, hungry, dynamic footballers. Attacking-wise we've added a lot of pace to the squad now, so that's something we can look forward to in the games.
"That’s something you need in the Championship and will put the opposition under pressure and that's something we need to do.
"But first and foremost from last season we need to eradicate the goals against column which is why we've brought in some really good defenders - in Jonathan (Grounds), Grant (Hall), Gavin (Gunning), and David Edgar, coupled with the ones we've got and Neal Eardley coming back."