Parasound A21+ power amp for my front L/R speakers -- overkill? Other options?

M

mtrot

Senior Audioholic
First, this system is in our mid-sized family room and my listening mix is 50/50 music/movies, 5.1 for movies, 2.0 for audio listening. My setup includes an Anthem STR preamp and I use the Home Theater bypass feature for movies. For two-channel, I have an Anthem STR preamp, which is connected to a power amp. Up until now, I have been using a massive Krell FPB 400cx for my fronts, so I don't want to either step down much in audio quality or break the bank replacing it. The reason it has to go is that we just got a new BDI equipment console and the Krell will not fit inside and I don't want to put the 100 pound beast on top of the BDI's glass top, either. It appears that I might be able to squeeze the A21+ into the BDI.

What I'm looking for is good bass slam with tower speakers and it seems the A21+ should be a reasonable replacement for the Krell in that regard. The silver A21+ is now on sale for $800 lower price than the black model. I figure such an amp will drive most any speakers I might get in the future.


Another option is the Anthem STR power amp, but Anthem now wants $6,500 for it. I can get the silver Parasound A21+ for about half that. Anthem rates the STR at 400 wpc, while the A21+ is rated at 300 into 8 ohm, although the A21+ is significantly heavier. The STR looks like it would more easily fit into the BDI console.


Any thoughts on these amps or suggestions for other options much appreciated.
 
TLS Guy

TLS Guy

Audioholic Jedi
First, this system is in our mid-sized family room and my listening mix is 50/50 music/movies, 5.1 for movies, 2.0 for audio listening. My setup includes an Anthem STR preamp and I use the Home Theater bypass feature for movies. For two-channel, I have an Anthem STR preamp, which is connected to a power amp. Up until now, I have been using a massive Krell FPB 400cx for my fronts, so I don't want to either step down much in audio quality or break the bank replacing it. The reason it has to go is that we just got a new BDI equipment console and the Krell will not fit inside and I don't want to put the 100 pound beast on top of the BDI's glass top, either. It appears that I might be able to squeeze the A21+ into the BDI.

What I'm looking for is good bass slam with tower speakers and it seems the A21+ should be a reasonable replacement for the Krell in that regard. The silver A21+ is now on sale for $800 lower price than the black model. I figure such an amp will drive most any speakers I might get in the future.


Another option is the Anthem STR power amp, but Anthem now wants $6,500 for it. I can get the silver Parasound A21+ for about half that. Anthem rates the STR at 400 wpc, while the A21+ is rated at 300 into 8 ohm, although the A21+ is significantly heavier. The STR looks like it would more easily fit into the BDI console.


Any thoughts on these amps or suggestions for other options much appreciated.
You bought the wrong console. However, you can place power amps anywhere. They don't even have to be in the same room. I would try and solve this without a huge downgrade.
 
Verdinut

Verdinut

Audioholic Spartan
First, this system is in our mid-sized family room and my listening mix is 50/50 music/movies, 5.1 for movies, 2.0 for audio listening. My setup includes an Anthem STR preamp and I use the Home Theater bypass feature for movies. For two-channel, I have an Anthem STR preamp, which is connected to a power amp. Up until now, I have been using a massive Krell FPB 400cx for my fronts, so I don't want to either step down much in audio quality or break the bank replacing it. The reason it has to go is that we just got a new BDI equipment console and the Krell will not fit inside and I don't want to put the 100 pound beast on top of the BDI's glass top, either. It appears that I might be able to squeeze the A21+ into the BDI.

What I'm looking for is good bass slam with tower speakers and it seems the A21+ should be a reasonable replacement for the Krell in that regard. The silver A21+ is now on sale for $800 lower price than the black model. I figure such an amp will drive most any speakers I might get in the future.


Another option is the Anthem STR power amp, but Anthem now wants $6,500 for it. I can get the silver Parasound A21+ for about half that. Anthem rates the STR at 400 wpc, while the A21+ is rated at 300 into 8 ohm, although the A21+ is significantly heavier. The STR looks like it would more easily fit into the BDI console.


Any thoughts on these amps or suggestions for other options much appreciated.
A good and more affordable alternate product is the following high efficiency Class D Hypex amplifier, and from a reliable seller:

 
M

mtrot

Senior Audioholic
You bought the wrong console. However, you can place power amps anywhere. They don't even have to be in the same room. I would try and solve this without a huge downgrade.
Lol, not very helpful. Are you saying you know of one that will hold my Krell? And that my wife would accept? I looked around quite a bit and didn't find one.
 
M

mtrot

Senior Audioholic
A good and more affordable alternate product is the following Class D Hypex amplifier, and from a reliable seller:

Thanks, I'm old school and not familiar with these class D amps. Can they sustain high output for extended periods? And would they work well with my Anthem STR preamp? I see that the Buckeye can produce 28A output current, while the Parasound can produce 60A.
 
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
Also check out ATI amps. They have both old school class AB 300WPC amps and class D 500WPC amps. All ATI amps come with 7 YR warranty.
 
Verdinut

Verdinut

Audioholic Spartan
Thanks, I'm old school and not familiar with these class D amps. Can they sustain high output for extended periods? And would they work well with my Anthem STR preamp? I see that the Buckeye can produce 28A output current, while the Parasound can produce 60A.
Usually in a home environment, sustained high output situations for extended periods don't happen, even in action movies.

I wish that @PENG will have a free moment to answer you. He is an electrical engineer and better knowledgeable on this question.
 
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G

Golfx

Senior Audioholic
Thanks, I'm old school and not familiar with these class D amps. Can they sustain high output for extended periods? And would they work well with my Anthem STR preamp? I see that the Buckeye can produce 28A output current, while the Parasound can produce 60A.
The class D amps are not “one” amp but many different amp modules the most powerful would be the Hypex NcoreX modules or the second generation Purifi modules. These are much smaller amps, run cooler and have the better bench measurements than the older Class AB amps.
The above give you some examples of reviews with many measurements.
But I also came from Class AB anthem amps. The below string turned me into a class d believer. PENG is short for professional engineer (retired EE) who is a respected advisor on many forums. This string details his conversion. But I know giving up the past is hard but you only have to read the measurements. Math is math.
 
M

mtrot

Senior Audioholic
Also check out ATI amps. They have both old school class AB 300WPC amps and class D 500WPC amps. All ATI amps come with 7 YR warranty.
Ah, yes, ATI. Thanks for reminding me about ATI; I remember them from back in the day. I will check them out.
 
TLS Guy

TLS Guy

Audioholic Jedi
Lol, not very helpful. Are you saying you know of one that will hold my Krell? And that my wife would accept? I looked around quite a bit and didn't find one.
You missed my point. Power amps can go anywhere within reason. They don't have to be in that room. I have 9 big power amps in my large AV system, but none of them are in the AV room.

So you have to think not necessarily within the room but outside the room. This is a time to get your creative juices going.
 
P

PENG

Audioholic Slumlord
Thanks, I'm old school and not familiar with these class D amps. Can they sustain high output for extended periods? And would they work well with my Anthem STR preamp? I see that the Buckeye can produce 28A output current, while the Parasound can produce 60A.
I have compared the buckeye amp thoroughly, including the REW graphs, and decided to give my A21 away to save space and before I get too old and weak to move that thing around.

1740312470343.png


Those 60 A current specs are silly because they never tell you how they measured it, and it might have been for some microseconds, really meaningless. All it says is "60 amperes peak per channel"

Harman Kardon and NAD are probably among the worse in perpetuating this so called high current capability myths, for example, Harmon's ex flagship AV receiver, yes, just an AVR that is rated 110 WPC into 8 ohms, has the high current spec 75 amps, taken right from the owner's manual:

High Instantaneous Current
Capability (HCC) +75amps

Does that mean such an AVR more current capable than the much bigger and heavier 2 channel Parasound, of course not, by the same token, you can based on the A21's spec and think it is more capable than the buckeye NC502MP amp that simply says:

Hiccup both channels after
limiting 40ms

not all that informative and such specs are not really relevant in real world applications where 500 W into 2 ohms means 15.8 A, or 22.4 A peak, that's well below the current limit set point of the buckeyeamp NC502MP.

The Halo A21 is only rated 400 W into 4 ohms, so current at rated output is only 10 A, peak will be 14.2 A.

The NC502MP is 2 ohms capable, whereas the Halo A21 is only rated for 4 ohms, though it can of course deal with impedance dips down to 2 ohms, just not rated for 2 ohms nominal loads.

Anyway, if you are interested, you can browse through the thread linked below, a poll was included:

Class D power amplifiers | Audioholics Home Theater Forums

The buckeyeamp is budget friendly, if you don't mind spending more, take a look of the Apollon amps:

Apollon Audio - Hypex NCore, Purifi Based Class-D Amplifiers

Any of those Hypex or Purifi based class D amps will have much lower distortions and noise than the Parasound A21 and your current Krell amp for sure.

The A21+ has a little more rated output but for low impedance loads especially with large phase angles, the Hypex or Purifi based class D amps are more suitable.

The STR preamp seems like a good match with those amps too.
 
Last edited:
M

mtrot

Senior Audioholic
I have compared the buckeye amp thoroughly, including the REW graphs, and decided to give my A21 away to save space and before I get too old and weak to move that thing around.

View attachment 72448

Those 60 A current specs are silly because they never tell you how they measured it, and it might have been for some microseconds, really meaningless. All it says is "60 amperes peak per channel"

Harman Kardon and NAD are probably among the worse in perpetuating this so called high current capability myths, for example, Harmon's ex flagship AV receiver, yes, just an AVR that is rated 110 WPC into 8 ohms, has the high current spec 75 amps, taken right from the owner's manual:

High Instantaneous Current
Capability (HCC) +75amps

Does that mean such an AVR more current capable than the much bigger and heavier 2 channel Parasound, of course not, by the same token, you can based on the A21's spec and think it is more capable than the buckeye NC502MP amp that simply says:

Hiccup both channels after
limiting 40ms

not all that informative and such specs are not really relevant in real world applications where 500 W into 2 ohms means 15.8 A, or 22.4 A peak, that's well below the current limit set point of the buckeyeamp NC502MP.

The Halo A21 is only rated 400 W into 4 ohms, so current at rated output is only 10 A, peak will be 14.2 A.

The NC502MP is 2 ohms capable, whereas the Halo A21 is only rated for 4 ohms, though it can of course deal with impedance dips down to 2 ohms, just not rated for 2 ohms nominal loads.

Anyway, if you are interested, you can browse through the thread linked below, a poll was included:

Class D power amplifiers | Audioholics Home Theater Forums

The buckeyeamp is budget friendly, if you don't mind spending more, take a look of the Apollon amps:

Apollon Audio - Hypex NCore, Purifi Based Class-D Amplifiers

Any of those Hypex or Purifi based class D amps will have much lower distortions and noise than the Parasound A21 and your current Krell amp for sure.

The A21+ has a little more rated output but for low impedance loads especially with large phase angles, the Hypex or Purifi based class D amps are more suitable.

The STR preamp seems like a good match with those amps too.
Thanks much for the information! Nothing to do with the quality of their products, but I checked out the Apollon site and they wax more eloquent and use more "audiophile" descriptions of their amps' sound quality than many other manufacturers!

What's the difference between Hypex and Purifi based units and upon what factors would one choose between them? Also, they offer a plethora of amps of each of those brands and I don't know how I would choose between them.
 
G

Golfx

Senior Audioholic
Thanks much for the information! Nothing to do with the quality of their products, but I checked out the Apollon site and they wax more eloquent and use more "audiophile" descriptions of their amps' sound quality than many other manufacturers!

What's the difference between Hypex and Purifi based units and upon what factors would one choose between them? Also, they offer a plethora of amps of each of those brands and I don't know how I would choose between them.
You are confused by too many choices and you want a recommendation to simplify your choice?

None of the high quality Hypex or Purifi amps on Buckeye or Apollon have “audible” differences in their SINAD. So just use the watts per ohm to make your decision.
 
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