Parasound Halo a-21 , One overlooked great amp


I have owned many pieces of audio gear.I can spend 3 x this much money
And still not do to much better or at all. John Curl the ex chief designer
For Mark Levenson designed theParasound Halo line and the A-21
Is a true classic in every sence this unconventional amp
Uses J fets for the input stage, Mosfets, for the driver stage and
8 matched Sanken Bipolar transistors for the output stage per channel even the specs are under rated by some 50 wpc into pushing over 450 wpc
And over 60 amps peak per channel .the 4 huge Elna capacitors
Gives plenty of storage. As well as the custom transformer.2 things I have found that dramatically improve this amplifier since this is a a A- AB design the1 st 10 watts are in pure class-A
Because of the current on tap there are 4-8amp T fuses inthe circuit board
1 for the plus and minus rails per channel, and a 12 amp Tforthe main fuse on back the Hifi tuning fuses- Supreme although expensive for these30 mm Fuses transform this amp across the board , also the better the high current Power cord you use the more you will be rewarded,
I am using a Synergistic Research T3 HC which may be expensive
And the fuses retail for $450 but the end result is like a major preamp upgrade over 10 percent across the board which is Huge inAudiophile
Terms. This amp is unique in that there is no negative feedback inthe circuit, and it is direct coupled ,with NO coupling capacitors at all in the amplifier signal path to dilute the signal,just the big power supply caps that have a
Small .1 uf cap used just as a bypass for hi frequency noise.
My friends new Bryston 4bsst2 was no where as natural once I gave the
hifi tuning fuses time to settle in . I got rid of the Bat vk500with bat pack
It was to colored compared. For under $2600 with fuses this amp can easilly compete with any amp at 2 x it 's price. The only amp I found that is a little Better in several areas is the Hegal-20 amp but it is more than 2 x the cost. Don' t let the reasonable price make you over look this classic
Amplifier the Parasound Halo A-21 is one of the best buys in all of audio
And can drive planers ,stats, or big cone speakers with ease and sound
Excellent doing it !!
128x128audioman58
I heard that the internal components have been changed couple of years back and are not the same brands, as when they were launched. Nevertheless this is a great amp. Overlooked? Hardly. Every piece that comes up on audiogon is sold within a couple of days, if not hours.
I have not tried the HiFi Tuning fuses on mine, as it sounds superb, as-is. But I did pose this question before in this forum and understand that people indeed have got very good results with the HiFi Tuning fuses.
Also good to know that you have actually heard the Hegel 20. I was thinking of this amp when I wanted to get a power amp in my system. Checked with folks on this forum. Besides the cost, the fact that I could not listen to the amp before buying, was a big deterrent.
Been very happy with the A21. Waiting to use the Balanced option, since my TVC is also balanced. But I don't have any source that is Balanced, hence have not used the Balanced option. And that reminds me, the A21 is better with Passive preamps, than the H 20, since it is has a higher sensitivity number.
Balanced is really no better ,Because the A-21 is not a true balanced amplifier
True balanced means you have to have transformer for each channel
Plus and minus. This amplifier RCA -balanced still connect together down stream
I owned the JC-1's a few years back and they were great mono-blocks. Parasound makes some fine gear. The only reason I sold them was because I went to tubes.
Well, after Thankful resurrected this thread, all I can say Audioman is - Balanced on this amp makes a ton of a difference in my system, as it provided me with the gain I needed. Also I feel the sound stage is also raised up considerably. The next thing I await is a Balanced CDP. The current CDP is RCA only and that is how it connects to the TVC.
Yes you are right ,you get more out put for the impedance is 66 which Is 2x the
Single ended, and therefor more output
The point I was trying to make is that it is not a true balanced amplifier
Pull the cover and see if you have a transformer plus and minus for each channel .
Audioman... you have good taste in what a great amp should do, or shouldn't!

Back in my home country my main system consists of a Pass front end onto the Krell 300cx. My system here while overseas is a Rowland front end onto the A-21. I should add the A-21 has nudged aside some Rowland 201 mono blocks for now... and they may just end up on the market!

This A-21 is one of the most musical amps I've owned, or heard. I've found decent power cords help significantly, I might give those fuses some serious consideration - thanks!! Allan
Another very happy owner chiming in, my Paradigm S6 present a difficult load that this amp handles without breaking a sweat! I'm looking to get the soon to be released Parasound preamp, P5, when it comes out this summer. It will have XLR outputs(not sure if its a true balanced design) so I'm curious to see if there'll be benefits there.

Can anyone recommend good XLR cables for a budget of 150?
Hey, I thought I'd update this thread and bump for a great amp. I ended up with a P7 preamp and Morrow Audio MA3 cabling with Eichmann silver bullet RCA's. With the Oppo 95, what a combo. It's the best system I've ever owned, and I'm done trying to tweak.

It's been kind of a long way to get there, trying all Emotiva components with Paradigm S6 speakers. I ended up really not liking the overly bright harsh sound. 4 years later after losing the Emotiva stuff, slowly getting the above mentioned components, I've gotten an education along the way. Forums like this have helped a lot.