Anyone have a pic to show me where to replace HEXFREDS in a Cary CAD-120S?

Don't do this! Find a tech in your area to do it for you. Don't risk damaging your amp or worse by attempting an upgrade yourself you are not qualified, by your own admission, to perform. Not to mention potentially tanking the resale value of your amp. A little common sense goes a long way here.

Follow your hot and neutral power cord leads(within the chassis) and among first connections, you’ll find three diodes, connected in series to each AC lead. Three will be facing cathode to AC supply lead and three: anode to AC lead. Mine had a single piece of shrink tubing, on each set of three and were strung between two terminal trips. If you know the cathode end of a rectifier from the anode end and are competent with a soldering iron. It’s a very easy process, to replace these with HEXFREDs. I mounted mine(in my Cary SLM-100s) on small blocks of Corian. If you feel competent and interested, I can email a couple pics of my install. Cary also offers the upgrade service, if not. (http://www.caryaudio.com/upgrades-and-modifications/)

thanks rodman. i'll DM you with an email addy. Thanks!

You've got mail!

You can do this simple mod with a little help. Very easy. Good luck! While you are it it replace those electrolytic power supply caps with film! Bigger improvement in sound.