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

[mtrot]

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.

Parasound A21+ High-Performance Stereo Amplifier

The Parasound A21+ delivers exceptional power, resolution, and sonic purity, making it the perfect stereo amplifier for high-end audio enthusiasts and home theaters.

parasound.com

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.

Anthem® | Power Amplifier | STR Power Amplifier | Overview

www.anthemav.com

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

 

[TLS Guy]

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.

Parasound A21+ High-Performance Stereo Amplifier

The Parasound A21+ delivers exceptional power, resolution, and sonic purity, making it the perfect stereo amplifier for high-end audio enthusiasts and home theaters.

parasound.com

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.

Anthem® | Power Amplifier | STR Power Amplifier | Overview

www.anthemav.com

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]

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.

Parasound A21+ High-Performance Stereo Amplifier

The Parasound A21+ delivers exceptional power, resolution, and sonic purity, making it the perfect stereo amplifier for high-end audio enthusiasts and home theaters.

parasound.com

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.

Anthem® | Power Amplifier | STR Power Amplifier | Overview

www.anthemav.com

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:

Buckeye Amps

Buckeye Amps utilizes the most advanced audio amplifier technologies available. Authorized seller for Hypex and Purifi Class D amplifiers. Based in the US. Free shipping and worldwide service!

www.buckeyeamp.com

 

[mtrot]

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.

 

[mtrot]

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

Buckeye Amps

Buckeye Amps utilizes the most advanced audio amplifier technologies available. Authorized seller for Hypex and Purifi Class D amplifiers. Based in the US. Free shipping and worldwide service!

www.buckeyeamp.com

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]

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]

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.

 

[Golfx]

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.

Apollon NCx500ST Stereo Amplifier Review

This is a review and detailed measurements of the Apollon NCx500ST stereo class D amplifier based on Hypex NCOREx NCx500 modules. It was kindly drop shipped from the member and costs 1,090.00€ (US $1,168) with standard opamp. While the case is stamped aluminum, it is a heavily customized one...

www.audiosciencereview.com

Apollon Hypex NC2K Monoblock Amplifier Review

This is a review and detailed measurements of the Hypex NC2K based amplifier from Apollon. The unit was kindly purchased new by a member and drop shipped to me for testing. The NC2K has different options and starts at 1.990,00€ or US $2,342 as of this writing. The version I have has the...

www.audiosciencereview.com

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.

Class D power amplifiers

Last time I shopped for the most transparent speakers I could find in the below $10,000 range I found them in a store in Toronto that powered the speakers with, surprisingly, class D amplifiers. In the end I bought the speakers without requesting them to try driving the speakers with my kind of...

forums.audioholics.com

 

[mtrot]

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]

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.

 

[PENG]

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.

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.

 

[mtrot]

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.

 

[DigitalDawn]

I second the ATI recommendation. Their class D amps are fantastic.

 

[Golfx]

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.

 

[PENG]

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.

Very little to no difference for real world applications so you can choose based on aesthetic and price.
Purifi's in general tend to have a little lower distortions and noise, but again no practical difference.


The specs of one of those are ridiculously good, in fact if you get the right such as the on reviewed/measured, the STR preamp will actually become the bottleneck, that is rare because preamp at the STR's caliber in general will have much lower THD+N than most power amps.

Hypex modules:

Apollon NCx500ST Stereo Amplifier Review | Audio Science Review (ASR) Forum:

Or Purifi modules:

Purifi 1ET7040SA DM Lux Dual Mono Amplifier | Apollon Audio

These kind of amps should have no trouble with low impedance and high phase angles, so pretty much can drive any speakers. Obviously so can your Krell, but that thing weighs over 100 lbs, high foot print, and at higher distortions/noise.

 

[mtrot]

So this is our new setup and the aesthetic my wife was looking for with the new console. The previous setup had very low WAF. One nice thing about these class D amps is how easily they will fit inside the console.

The McCormack DNA-1 Deluxe Edition amp on top just barely won't fit in the console. It sounds pretty good but may not have quite the slam of my Krell. If I decide to go with new class D amp(s), I can sell both the Krell and DNA-1.

 

[PENG]

So this is our new setup and the aesthetic my wife was looking for with the new console. The previous setup had very low WAF. One nice thing about these class D amps is how easily they will fit inside the console.

The McCormack DNA-1 Deluxe Edition amp on top just barely won't fit in the console. It sounds pretty good but may not have quite the slam of my Krell. If I decide to go with new class D amp(s), I can sell both the Krell and DNA-1.View attachment 72452

Very nice setup, your front 3 speakers surely love current! They will do well with Bruno's class D amps.

By the way, Bruno is main guy in the design/development of both the Hypex and Purifi modules, here's a good article that he and Gene worked together on a few years ago, don't let anyone talk you out of class D amps!

Audiophile Myths About Amplifier Negative Feedback Debunked

and some about Bruno:

EXPERT opinion: Bruno Putzeys (Purifi, Hypex, Kii, Mola Mola) | Darko.Audio
Bruno Putzeys - Wikipedia

I wonder what would be the shipping cost of that monster Krell amp you have, I am not interested but curious about what would the potential buyer say about the shipping cost lol..

 

[mtrot]

Very nice setup, your front 3 speakers surely love current! They will do well with Bruno's class D amps.

By the way, Bruno is main guy in the design/development of both the Hypex and Purifi modules, here's a good article that he and Gene worked together on a few years ago, don't let anyone talk you out of class D amps!

Audiophile Myths About Amplifier Negative Feedback Debunked

and some about Bruno:

EXPERT opinion: Bruno Putzeys (Purifi, Hypex, Kii, Mola Mola) | Darko.Audio
Bruno Putzeys - Wikipedia

I wonder what would be the shipping cost of that monster Krell amp you have, I am not interested but curious about what would the potential buyer say about the shipping cost lol..

Thanks much,

The Sonus Faber Lumina V are rated 4 ohm, but the Polk center speaker is rated 8 ohm and sensitivity at 88 dB.

As to those Apollon amps from Europe, I wonder if they offer a trial period and return policy if I don't like them or any issues or problems arise.

Regarding class D amps, I have a buddy in Denver who is recommending Starkrimson Mono's but the output is 150 watts. They offer a 500 watt amp, but it costs $2500. Know anything about these? I like that they are in the US.
https://orchardaudio.com/shop/starkrimson-mono-premium/

Regarding the Krell amp, yes, I can only guess over $200 for ground shipping or freight.

 

[Golfx]

Thanks much,

The Sonus Faber Lumina V are rated 4 ohm, but the Polk center speaker is rated 8 ohm and sensitivity at 88 dB.

As to those Apollon amps from Europe, I wonder if they offer a trial period and return policy if I don't like them or any issues or problems arise.

Regarding class D amps, I have a buddy in Denver who is recommending Starkrimson Mono's but the output is 150 watts. They offer a 500 watt amp, but it costs $2500. Know anything about these? I like that they are in the US.
https://orchardaudio.com/shop/starkrimson-mono-premium/

Regarding the Krell amp, yes, I can only guess over $200 for ground shipping or freight.

I can answer regarding the apollon. I recently purchased their dual mono block purifi design. I have to caution you they are very slow delivering and import/export customs on each end was not easy. I always had to stay involved to make things happen. It was frustrating. They are the BEST made build wise but do not offer returns on the higher costs builds—kind of a bummer. They will say 14 day return but that is only on cheaper stock they have on hand.

Buckeye’s cases are little cheaper looking but many owners are very happy with their amps.

I also bought from Nord Acoustics. Better cases and assembled in england and offers a cheap added option to pay import fees and provides you with a US based repair site. https://nordacoustics.co.uk/

March Audio from Australia. Better cases, great builds, fast delivery and Australia is a free trade country so no import hassles or fees. https://marchaudio.com/?ph=520e08a63daa08ffebfa06f6