Hello Ajpat -
All my amplifier designs share the same pedigree, so there are inevitable similarities. The DNA-225 is a newer design, so it includes a variety of improvements developed since the DNA-2 was created. On the other hand, the DNA-2 is somewhat more powerful and is laid-out as a dual-mono topology, so it could be said to have certain advantages. Which amp is right for you depends on several factors, and I would be happy to go over these with you. Please e-mail or call me directly.
Best regards,
Steve McCormack
www.SMcAudio.com
760-732-0352