Probably not. The Atom and the THX 789 are known for how quiet they are. I use the Atom with high impedance phones: HD 6XX, HD 600, AKG K240 Sextett; lower impedance
phones: Grado SR60, MEZE 73 Classics, Superlux HD 681 EVO, and the Atom works quite
well with each of them. The THX 789 comes in handy with really power hungry headphones, where its balanced mode really shines. Otherwise it's overkill.
The THX 789 is still a bargain at...