As per title… Upgraded the CPU in my Dell from an i5 4460 to an i7 4790k.
Opened Cubase 11 and the audio, even the click, is completely distorted. (multiple projects, even new ones, not just a certain one)
Checked in Cubase 9.5, audio works fine.
Played a few mp3s in Windows Media Player, audio works fine.
Re-installed Cubase 11; problem persists.
Now idea why a CPU upgrade would cause this to happen to just one version of Cubase, but that is the only thing that I did today.
Surely it was not the CPU update, but some ASIO thing.
I didn’t change any settings with regard to that. I’ve been using the same Scarlett 18i8 for years. I was using Cubase 11 just fine yesterday.
Like I said, that was the only thing I changed about my system.
I’m open to the idea that it’s somehow not related to the CPU upgrade, but it would be bizarrely coincidental.
Have you been into the bios after upgrading the cpu? Are you overclocking?
I went into the BIOS briefly just for a look; changed absolutely nothing.
Never overclocked a thing in my life; never looked into it.
I imagine though, that such things might cause system-wide problems, and not just affect one application…?
But have you verified that your settings have not changed?
Have you reinstalled the driver?
Do you know that some installers query the CPU and motherboard during install?
Is the fan secure?
Does this CPU get hotter?
Changed drivers in Studio Setup, still distorted.
Downloaded Cubase 12 free trial. Same problem…
I didn’t suggest changing drivers…
The first thing you mentioned was ASIO (drivers), so I tried changing to a non-Focusrite one to see what would happen.
Have I reinstalled the driver for what…?
Any setting or driver that goes on the ASIO path can be suspect.
Since I can’t go through all the possibilities on your system, I can only speak generally.
OK… Absolutely bizarre coincidence it did indeed turn out to be.
I have a bunch of plugins bypassed on the Control Room inserts. I decided to try and actually turn them fully OFF to see if the problem went away, which it did, when I turned off the bx_solo plugin.
When I opened it, it was saying that I needed to activate it, and that there was a 14 day free trial… I checked their website; the plugin is still completely free. I signed in when prompted and now it seems to be working again.
So an ‘unlicensed’ (even though it’s completely free) instance of bx_solo that was BYPASSED on my Control Room inserts was causing terrible distortion, and it chose just to happen right after I installed the new CPU.
On the positive side, it forced me to just do 6 BIOS updates. 
I wonder if the change of cpu meant the authorisation didn’t match your computer anymore. Cubase 12 has certain things that if changed will lose authorisation. Cpu at least doesn’t sound like one of them but this plugin does. Glad you found the problem.