Billheiser
Headphoneus Supremus
Perhaps not intentionally but this does come across as some what condescending perhaps why not simply identify the companies it is a interesting subject and I suspect many would be interested in learning more.
Yes possibly condescending, i see your point. Sorry! Anyway, i'll tell you the three out of the top four, but the one that has nailed it i wont mention because we should be allowed to have some secrets. F1 driving teams don't go telling the competition how they tune their engines if you know what i mean.
1: Softube
2: UAD
3: IK Multimedia
Generally F1 teams tell you their name if they exist. I haven't seen Ferrari or anyone else run a plain black car with no logos.