Quote Originally Posted by skeet0037 View Post
Can anyone tell me if I am able to use my HK PM640 Vxi integrated amp as a pre amp with a David Hafler DH220 amp. until I am able to purchase a proper pre amp.

Thank you..
Welcome to AR Forums, Skeet.

Unfortunately it looks like this older HK amp has no 'Preamp Out' connections which would be necessary to use it as a preamp. It has only 'Tape Out' connections: usually these are not useful to control a power amp because they are not affected by the volume control.