My initial impressions switching from Parasound Halo to an ATI AT524nc

[Cos]

I did not really expect to notice any sonic difference, I wanted to give Class D a try

I was considering switching with the following reasons:

• Lose some weight on my amps (partially solved, still pretty heavy)
• Get rid of the slight "Hiss/Power Buzz" that was coming from my tweeters (Check)
• More power efficient amp (Check)
• If it was sonically a wash, sell my A31/A51 consolidate to 2 amps instead of 3 and pocket a little $$ for other things (In Process)

I was completely happy with the sound quality from my Halos and I am happy to report, I don't feel like I lost anything switching over to the class D ATI. Will live with it for a few weeks and if all goes well, will change over completely. I am also going to give my untested opinion: I felt there were some sonic differences, but I am not going to even touch the subject, because I have done no testing to back that statement up. Going to play around with it over the weekend.

Parasound Halo A31

• Halo wins the beauty contest hands down, its also packaged nicer with a double box
• I like the fact that Halo has a 12v Trigger input and output + threshold knob
• Manual Gain control and THX Ultra2 certification (Not a big deal)
• Amp Transformer hum can only be heard if I put my ear next to the unit
• Sound Quality is excellent, no complaints
• Had slight tweeter noise that can only be heard 2-3 feet away from speaker, but the anal retentive person that I am, wanted to get rid of it.

ATI AT524NC

• The ATI is not the prettiest amp, but this will go into my equipment room
• It is DEAD SILENT - I do not hear transformer hum, and the slight Tweeter noise I noticed on my A31 is gone (This was a huge selling point for me)
• Only 1 12v Trigger Input, not a huge deal as my Pre/Pro has 2 outputs and I plan on running 2 amps
• It is about 25-30lbs lighter then the 80lb Halo, which is nice but still heavy
• As far as moving it, even though the weight is more than other class Ds, it's smaller form factor (not as deep) makes it a lot easer to take in and out vs the longer Halo because of the more centralized weight distribution
• I like the speaker binding posts better on this vs the Halo
• Save significant $$$ vs the comparable Halo

Bottom line for me was that class D impressed, not going to complain about a 7 year warranty either.

 

[flyboylr45]

My last amp was a Mcintosh MC-452. All I can say is, these things kick ass. I have 13 channels of ATI class D amplification (544, 542, 527). Not going back. Yes, the Mcintosh was beautiful to listen to even when it was off.

 

[PENG]

I did not really expect to notice any sonic difference, I wanted to give Class D a try

I was considering switching with the following reasons:

• Lose some weight on my amps (partially solved, still pretty heavy)
• Get rid of the slight "Hiss/Power Buzz" that was coming from my tweeters (Check)
• More power efficient amp (Check)
• If it was sonically a wash, sell my A31/A51 consolidate to 2 amps instead of 3 and pocket a little $$ for other things (In Process)

I was completely happy with the sound quality from my Halos and I am happy to report, I don't feel like I lost anything switching over to the class D ATI. Will live with it for a few weeks and if all goes well, will change over completely. I am also going to give my untested opinion: I felt there were some sonic differences, but I am not going to even touch the subject, because I have done no testing to back that statement up. Going to play around with it over the weekend.

Parasound Halo A31

• Halo wins the beauty contest hands down, its also packaged nicer with a double box
• I like the fact that Halo has a 12v Trigger input and output + threshold knob
• Manual Gain control and THX Ultra2 certification (Not a big deal)
• Amp Transformer hum can only be heard if I put my ear next to the unit
• Sound Quality is excellent, no complaints
• Had slight tweeter noise that can only be heard 2-3 feet away from speaker, but the anal retentive person that I am, wanted to get rid of it.

ATI AT524NC

• The ATI is not the prettiest amp, but this will go into my equipment room
• It is DEAD SILENT - I do not hear transformer hum, and the slight Tweeter noise I noticed on my A31 is gone (This was a huge selling point for me)
• Only 1 12v Trigger Input, not a huge deal as my Pre/Pro has 2 outputs and I plan on running 2 amps
• It is about 25-30lbs lighter then the 80lb Halo, which is nice but still heavy
• As far as moving it, even though the weight is more than other class Ds, it's smaller form factor (not as deep) makes it a lot easer to take in and out vs the longer Halo because of the more centralized weight distribution
• I like the speaker binding posts better on this vs the Halo
• Save significant $$$ vs the comparable Halo

Bottom line for me was that class D impressed, not going to complain about a 7 year warranty either.

My A21 hums too, and the A31 has a slightly larger transformer so I am not surprised it would hum. Class D amps are the way to go, much more intelligent design, lighter, smaller, quieter (mechanical noise) and most importantly, higher efficiency/run cool.

Congrats!!

 

[Cos]

My A21 hums too, and the A31 has a slightly larger transformer so I am not surprised it would hum. Class D amps are the way to go, much more intelligent design, lighter, smaller, quieter (mechanical noise) and most importantly, higher efficiency/run cool.

Congrats!!

The biggest issue it solved for me was the tweeter noise (even though is was only audible within 2 ft of the speakers), that along with not impacting sound quality would have been enough. The main reason I decided on ATI, was the warranty. It is 4-5 years longer than any of the competition.

Side note, I called ATI for support for a question about the cord. Its has a 20A power connector on the amp with15A wall plug. Someone actually picked up, took the time to answer that question and a few others, so A+ on support for me so far.

 

[AcuDefTechGuy]

My last amp was a Mcintosh MC-452. All I can say is, these things kick ass. I have 13 channels of ATI class D amplification (544, 542, 527). Not going back. Yes, the Mcintosh was beautiful to listen to even when it was off.

Ya, those Macs feel great to look at, but feel really bad on the stomach/wallet.

Did you ever listen to the tweeters when you had those Macs? Were they dead silent like the ATI amps?

I remember when I auditioned the 802D2, the dealer was using a big Classe amp and preamp. And I could hear the HISS sound from about 4 feet away.

 

[flyboylr45]

A little hiss from the marlen head up.

 

[Irvrobinson]

ATI amps all look like they used Adcom from the 1990s as their case design model. They're all ugly, IMO. Customer support and service (one AT3000 channel failed on me) is very good. The use of an old-fashioned linear power supply in their class D models is disappointing, but I'm not sure if it would preclude me from buying one.

 

[Trebdp83]

Yeah, the ugly ones tend to try and make up for it in customer "service".

 

[PENG]

The biggest issue it solved for me was the tweeter noise (even though is was only audible within 2 ft of the speakers), that along with not impacting sound quality would have been enough. The main reason I decided on ATI, was the warranty. It is 4-5 years longer than any of the competition.

Side note, I called ATI for support for a question about the cord. Its has a 20A power connector on the amp with15A wall plug. Someone actually picked up, took the time to answer that question and a few others, so A+ on support for me so far.

Did you read the review/measurements? I just checked and found the ATI525NC (measured by ASR) has much lower noise level than the A21+ (measured by Stereophile), the improved version. Stereophile measured SNR at 1 W and ASR 5W but even after the conversion the AT525NC should be significantly quieter, like silent, compared to the A21+. So it is predictable! The ATI amp also has much lower distortions but that won't matter as the A21's low enough.

The A31 is not a noisy amp either, you must have a very quiet room and your speakers may be on the sensitive side.

 

[Jeff R.]

Yeah, the ugly ones tend to try and make up for it in customer "service".

Just like some of of the ladies...


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[AcuDefTechGuy]

A little hiss from the marlen head up.

Oh, so Macs also have that hissing sound?

 

[AcuDefTechGuy]

Did you read the review/measurements? I just checked and found the ATI525NC (measured by ASR) has much lower noise level than the A21+ (measured by Stereophile), the improved version. Stereophile measured SNR at 1 W and ASR 5W but even after the conversion the AT525NC should be significantly quieter, like silent, compared to the A21+. So it is predictable! The ATI amp also has much lower distortions but that won't matter as the A21's low enough.

The A31 is not a noisy amp either, you must have a very quiet room and your speakers may be on the sensitive side.

It seems the Parasound, Macs, Classe have the hiss. What measured noise level do you think will predict this hiss noise?

 

[flyboylr45]

It was very very minimal and you had to be very close to the tweeter. I'm OCD and the fact that it was there bothered me, specially considering the price of the Mac but, at the listening position it was not noticeable at all. But I knew it was there. The ATI is dead quiet.

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[AcuDefTechGuy]

It was very very minimal and you had to be very close to the tweeter. I'm OCD and the fact that it was there bothered me, specially considering the price of the Mac but, at the listening position it was not noticeable at all. But I knew it was there. The ATI is dead quiet.

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Wow. Yeah. Apparently most of us are OCD even though most things are inaudible. But it is our money. And when we pay THAT much, we have the right to expect certain things.

I always thought Macs were dead silent. But now we know they are not dead silent thanks to your sacrifice.

 

[Cos]

Did you read the review/measurements? I just checked and found the ATI525NC (measured by ASR) has much lower noise level than the A21+ (measured by Stereophile), the improved version. Stereophile measured SNR at 1 W and ASR 5W but even after the conversion the AT525NC should be significantly quieter, like silent, compared to the A21+. So it is predictable! The ATI amp also has much lower distortions but that won't matter as the A21's low enough.

The A31 is not a noisy amp either, you must have a very quiet room and your speakers may be on the sensitive side.

The A31 is not noisy, I had to be 2 feet or less to hear at the tweeters. Yes, I did all the measurements analysis, specifically reviewing audiosciencereview's comments. My Speakers sensitivity is ~ 92dB so a bit on the higher side. I am OCD as well when it comes to the noise.

I read the same review in sound and vision and also read the part where the reviewer changed out his A51 for the ATI. If I didn't care about the weight and the super minor hiss, I would have been happy with either. The blue light on the ATI is annoying, but that is easily covered.

 

[AcuDefTechGuy]

I just tested my Yamaha MX-A5000 amp. All the tweeters on my RBH SX-T2R are dead silent with my ear pressed against those tweeters.

That means my Yamaha MX-A5000 is SOTA, while the ripoff Macs are not SOTA.

Alright, now who has some Legacy Audio amps to test?

 

[ryanosaur]

Alright, now who has some Legacy Audio amps to test?

You're the authorized dealer, can't you get a demo model?!

 

[Hetfield]

My Parasound HCA-1205A amp has a slight hmm or hiss. Most of the time I can't hear it but sometimes I do pick up on it and it does annoy me.

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[Out-Of-Phase]

Ya, those Macs feel great to look at, but feel really bad on the stomach/wallet.

Did you ever listen to the tweeters when you had those Macs? Were they dead silent like the ATI amps?

I remember when I auditioned the 802D2, the dealer was using a big Classe amp and preamp. And I could hear the HISS sound from about 4 feet away.

Interesting. My old Classe CP50 and CA200 were silent. My Crown XLS amp has some hiss, but you have to be close.

 

[Irvrobinson]

You just keep right on posting your equipment list, @flyboylr45. Every time I read it I feel like I’ve spent quite modestly on audio equipment.