After my 15 year old Goldmund amp broke, I bought an A21 in 2015 to fill the need until either the Goldman could be repaired or replaced with a top of the line power amp. After almost 2 years, local shops are still trying to fix the Goldmund and the A21 has done a wonderful job in my system. Strong bass, natural mids and extended highs. In addition to the trigger voltage feature, it has a input signal sensor that I use to couple it with my Conrad Johnson preamp because the CJ does not have a trigger outlet.
Very good sound - maybe a bit lacking in timbre and soundstage when compared to some of my expensive amps of the past. Built like a tank. Runs cool, even when pushed to high volumes. I'm in no hurry to replace it.
My journey to refresh my audio system began with the replacement of my Sonus Faber Grand Piano Domus with the Sonus Faber Cremona Auditor M. After that, it was the DAC (Perpetual Technologies P1/P3 combo) to Wyred4Sound DAC2 DSDse, then my CD Transport (Northstar 192 Transport to Wyred4Sound MS-2 music server), and finally my Power Amp (I ran the DAC direct to the Power Amp). This took the longest as I wanted to make sure that the eventual replacement to my Bel Canto S300 would be a worthy one. Besides equipment, I also changed out my cables (DH Labs HDMI cable from Wyred4Sound MS-2 to DAC, SoundSilver Clarity silver conductor XLR cables from DAC to Amp, & TelluriumQ Ultra Black loudspeaker cables from Amp to Loudspeakers). Hence, it was a total refresh.
I did my usual research online, and trawled the various online audio magazines for suitable candidates. My requirement for the replacement amp includes relatively high power (more than 300W at 4 ohm), good damping factor, high current capable, reliable, and of course musical and within my budget (not more than $3000). Since my Bel Canto is a Class D amp, I am ok with looking at another Class D amp to replace it, although I did not restrict my search to just Class D amps. That was a good move, because that was when I came across the Parasound A21.
I am acquainted with Parasound, as my first audiophile quality CD player was a Parasound CDP-1000, and later I bought a Parasound DAC-1500 to upgrade the overall source quality. That was back in 1996. Back to the present time. Over the course of the next 3 months, I went on and auditioned similar priced amps from Wyred4Sound, Bel Canto and eventually the Parasound. I guess it was the fact that the A21 is a Class A/AB design that made the difference (between the Wyred4Sound & Bel Canto). The Class D amps, while very good sounding and good at what they can do for the price, there is a noticeable hardness in the upper registers and frequencies. This became very apparent once I noticed it, and it is present in all recordings and playback. For the A21, no matter how hard it was driven, there was no hardness at all. The upper registers and frequencies sounded sweet and very listenable. In crescendos and complexes musical passages, the amp sounded relaxed and musical. It did not give me any listening fatigue at all. In fact, it made listening to music enjoyable again.
As mentioned in any other reviews, the A21 does not favor any particular frequency range. He music just came through as it was meant to be. Of course,the quality of the sound is dependent on the quality of the recorded music, as well as the source and ancillary equipment. In my system, the A21 really allowed me to enjoy my music in ways I did not before. The entire system is more coherent and musical than before the refresh. And now Inhabe the added benefit of convenience with the Music Server from Wyred4Sound. Listening to music has never been this fun and easy. I did not miss the cleaning and preparing of my CDs before playing etc. After all, listening to music is supposed to be fun and relaxing.
In summary, the A21 was the final piece of my equipment refresh journey. It was an apt one, as it truly allowed wonderful music to be played in my new system. For the price, it is an excellent value and, most of all, it does not leave me wanting to look for something better (which I am sure there are for a lot more money). As so many reviewers have said before me, the A21 is a no-brainier and indeed highly recommended! Thank you Parasound for making such a wonderful product at this price point, and bringing musical enjoyment to the masses! I am once again a fan.
I have had amplifiers by McCormack, Pioneer, SAE, Odyssey and a few others. This amp by Parasound is head and shoulders better than those amps.
I had wanted an Odyssey Stratos for many years. But as fate had it, when I got one tI had nothing but problems with intermittent noise and hum. After many, many months of trying to get it fixed I got rid of it. When I took the plunge with the A21, it was massive and quite powerful. But it delivered in a subtle way, as well. It was good with at low volumes and natural sounding at higher volumes. I paired it with a Parasound P3 preamp and it was just.... astonishing.
The only other amp I heard and liked as much, was a Musical Fidelity integrated dual mono that was twice the price.
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. I'd always watched the volume levels in the townhouse since the side walls are shared with neighbors, so when we got to the house, I was finally able to crank it up, and I mean loud.
That's when I noticed for the first time that the sound seemed bright, and uncomfortably so. At the moderate levels I'd been using previously and the previous pre amp, an Anthem TLP-1, it wasn't forward sounding, but with the XDA it sure was. Many different solutions were tried, but to make a long story short, after researching Parasound I thought the A21 would be an improvement.
Was it ever. I compared it side by side with the XPA amp. Using certain tracks, I could get distortion or sibilance when vocalists pronounced an "esss" at volume peaks of 82db. Swap in the A21, same tracks and volume, absolutely no distortion. It was bizzare and repeatable. That's when I noticed that the A21 had nicer highs, and mid range vocals were smooth and detailed like the XPA wasn't. Better bass too, more accurate. I sold the XPA amp. It is a decent entry level amp, and an improvement over receivers, but in the end that's about it.
The A21 is built like a tank, and images like I'd never experienced. It has many options including variable gain knobs, auto turn on/trigger on, rca outputs, XLR/RCA inputs, and Class A operation for the first 10 watts. Class A is nicer sounding although it is subtle for most. By comparison, the only thing the XPA amp line has is the XLR inputs.
After some more experimenting, I got their P7. Then I got Audioquest Type 4 speaker cable(in bulk by the foot at $120 for 24 feet.), and Morrow Audio MA3 interconnect cables. Every change brought about an improvement in the end result. The amp has the benefit of having great detail and resolution so better speakers will reward you with air and detail that gives superior imaging than a bargain brand amp. After 2 years, I really feel like it's the last amp I"ll ever buy.