Sorry I missunderstood what upgrade you were looking for. I thought is was a CODEC upgrade. The upgrade you are getting may help you, I had an MSD4 a few years back that when used as a D/A convertor it would cut off the first 2-3 seconds of each song on a CD as it searched for the proper code. I called Mcintosh and they fixed if for free.
Did McIntosh give a quote on doing the upgrade, I would not be suprised if they do it for free. I had to just pay the shipping back to them and they fixed and shipped it at no charge. I had bought the MSD4 used and when I told them I wasn't the original owner, the response was "Does it say McIntosh on it? then it's no charge" If they do charge you call audioclassics.com and see if they can do it cheaper and they may be able to answer if the upgrade will fix the problem.
Did McIntosh give a quote on doing the upgrade, I would not be suprised if they do it for free. I had to just pay the shipping back to them and they fixed and shipped it at no charge. I had bought the MSD4 used and when I told them I wasn't the original owner, the response was "Does it say McIntosh on it? then it's no charge" If they do charge you call audioclassics.com and see if they can do it cheaper and they may be able to answer if the upgrade will fix the problem.