Prabhupāda: Oh, yes. Therefore it is called mahā-mantra.
Doctor: But I was told that the Sudarśana-cakra words, mahāmāla parakramāyā maha patanivaya bhakta jane kalpanaya, that is a very powerful mantra.
Prabhupāda: Yes. Everything in relationship with God is powerful. But the name in this age is the most powerful: kīrtanād eva kṛṣṇasya mukta-saṅgaḥ paraṁ vrajet (SB 12.3.51).
Doctor: And the word oṁ has been praised in the Upaniṣads, but . . .
Prabhupāda: Oṁ, veda, praṇavaḥ sarva-vedeṣu. Kṛṣṇa says that raso 'ham apsu kaunteya prabhāsmi śaśi-sūryayoḥ praṇavaḥ sarva-vedeṣu (BG 7.8). Praṇava is oṁkāra. Sarva-vedeṣu, "That praṇava I am." That is sound representation of Kṛṣṇa.
Doctor: Then that one word as a mantra, is it not . . .
Prabhupāda: Yes.
Doctor: . . . the highest sort of word?
Prabhupāda: No. If you keep Kṛṣṇa that, "This praṇava is the sound representation of Kṛṣṇa," then it is all right. If you think it is separately powerful than Kṛṣṇa, that is nāma-aparādha.