What to do with broken McIntosh Pre-Amp

If you choose not to get it fixed.  This is an alternative.
https://www.schiit.com/products/saga-2?gclid=Cj0KCQjwz8bsBRC6ARIsAEyNnvqllaIsuLvQd6vC9HJQ7IwdvF_3v0WJXXWKUVx4PNYqMhNHcDVJS-oaAm6HEALw_wcB

or you could send it here

Thank you all for your recommendations.  I’m going to try that $50.00 Chase controller for now and send out the pre-amp for repair later.

The folks at Audio Classics are  THE source to repair your  MAC. Steve or any of his staff will work with you and offer options or solutions based on your conversation They ‘hear’ you and are as honest as the day is long.  good luck whatever route you choose 

Search the Internet for a good used tubed preamp like an Audio Research, Conrad Johnson, or Vacuum Tube Logic