"I'll just stress for a final time that the Parasound Halo A 21 and A 31 are awesomely talented. Living with them has witnessd an endlessly appealing combination of jaw-dropping grunt and dynamics with a warmth, even-handedness and general civility."
Stereo&Video (May, 2014) "This amazing group of equipment best demonstrates the audio industry's present state of the art."
SoundReproduction.com, October 2005
"Out of the box the A 21 sounds wonderful. I sampled several Red Book CD's of different recording quality and musical genera's and quickly came to the realization that the A 21 was indeed a very special amplifier, and I could not wait to begin the serious evaluation after burn-in." - Shane Mattson
Audioholics, December 2004
Product of the Year Award 2004 - Two-Channel Power Amplifier
"For those who desire the power of a Mack truck with the finesse of a Mercedes Benz in a two-channel amplifier, look no further than Parasound." "With the assortment of unbalanced and balanced inputs, triggered output, and ground lift option no stones were left unturned with this well built, attractive design."
Audioholics, October 2004
"The A 21 and A 51 amplifiers are both loaded with usable features above and beyond most other amplifiers in today's market." "I cranked the volume way up and found myself free of that inhibiting audio alarm in my head that nags at me to turn it back down. Using the Parasound amp allowed my speakers to portray every aspect that I had come to expect without adding any noticeable sign of distortion or flaw." "The Parasound Halo A 21 and A 51 are top rate amplifiers at a great value. Parasound seems to have attended to every aspect of their design including the excellent build quality internally and externally matched with great looks." Overall Rating: 5/5 Stars - Ken Stein and Steve Dellasala