Considering the tested Spritzer universal ones are $35 and a decent 12v 1A wall wart is about $20, I'd probably just grab the guaranteed one for $35.
Though if it was really me, I have a couple wall warts that meet the specs laying around for model projects anyway so I'd probably take my chances.
I can do so too, and I have some various power supplies to test from.
And I can easily hook them up to try out.
But no need for me to brag about it!
If dede4metal can not , first failed attempt of buying a wall wart cheaper there will already have cost him more than buying one from spritzer!
The small added price from spritzer is his pay for testing and finding a wall wart that does feed a driver without adding anything to the sound.
And we all have expenses to pay!