Summary: I noticed an earlier review comparing the A21 to an Emotiva amp, and since I owned and reviewed an Emotiva XPA-3 amp back in 2010, I thought I'd review this excellent amp. I bought the Halo in 2012, after moving out of a small townhouse and into a largish detached home. I had been using the XPA-3 with Paradigm Signature S6 speakers, a emotiva cd player and their XDA-1 DAC as a pre amp.
Summary: Purchased in July 2014. The amp has been around for years. No 21.2, no 21ES.....just the same amp; and there is a reason. This has got to be the one giant killer of sustained value the audio world has ever seen. The power and circuitry are phenomenal. I have played this amp through the Rockport Altairs and the Odyssey Audio Kismet reference. In a word, the flow of music was so evolved and liquid....silky with abundant detail.
Summary: l bought the Parasound halo a21 and the differences of improvement in the sound quality are just unreal, it's like too good to be true, before the parasound i had an Emotiva XPA and after listened to the differences btw the emo and the parasound i got to the conclusion that emotiva made my speakers sounded so bad, the sound quality is night and day differences, I'm was shocked!!
Summary: The A21 has got to be one of the best kept secrets ever. I bought it second hand for less than half the original retail price. Wonderful performance driving any speaker load, and I've run it with seven different speakers thus far, both conventional and planar. The amp is like a diesel engine, pulling an incredible amount of low-end grunt from recordings where I had formerly never known it existed.
Summary: The parasound Halo A21 is a heavy amplifier. Great quality looks and build, handles on the back and heat fins on the side, the blue lights look good at night. 250 watts per channel, it has plenty of power to run inefficient speakers, such as my JSE infininite slope 1.8 with 4 drivers. Using Cardas quadlink speaker and interconnect, this needs a good break in period and open cabinet where the heat can escape.
Summary: The Parasound A21 is an extremely heavy amp weighing in at 60 pounds. It is rated for 250 watts per channel, 8 ohms. It is capable of running in mono mode, with balanced or unbalanced connections, and gain adjustments on the back. Great build quality, large handles on the rear (may be needed when moving this) and is deep at 22 inches, requiring a large and strong shelf.
Summary: I had upgraded my speakers (PBN Audio Montana SPX) after listening to them in the shop powered by a set of Halo JC1 mono blocks. I got them home and hooked them up to my McIntosh 6 ch home theater amp ( 85/watts/ch ) which is not a bad amp but they were missnig something. I can not afford nor have the room for the mono blocks so my salesman suggested I try using the Halo A21. I brought the amp home hooked it up and there was the sound that I so loved in the showroom.
Summary: This is one serious amp.I cant believe Parasound can market this product for 2 large.I shopped at high end shops in the north Jersey area and they showed me amps at two times the price that could not shine the shoes of this beast.I recieved the amp via ups and they left it on my stoop while I was at work.No need to worry cause no ordinary thief was gonna be able to carry this piece of audio excellence away.Boxed up the weight was 77 lbs.
Summary: Good Lord is this a great, great amplifier. The sonic prowess and downright agility this amp can muster with a dregree effortlessness is worthy of accolades. You have a world class designer coupled to a company that's large enough to take advantage of economies of scale and deliver those savings to the consumer. Thank You John Curl, Thank You Parasound! Finally, I've got the sound I've been after but could never justify the cost.
Summary: I have to completely agree with the other reviewers. The A21 provides world class sound at a mid-fi price. This was on my shortlist of amps 200 watts+. I got the upgrade bug and went for a Pass Labs X250.5. The Pass is a work of art and is a real brute. Throws the largest and widest soundstage of any amp I have owned and had tremendous bass slam but like most high end solid state, it is extremely hyper detailed in the upper frequencies. Now I'm not slamming Pass Labs.