Is anything wrong with my Anthem MCA-525?

[Andrein]

It is about trade off, compromise, choices etc. that we all have to face, given a budget and other constraints that we have to work within. Some designers prefer as pure and direct audio path as possible so they don't want to use too much transient suppression and/or relay isolation that they believe would jeopardize sound quality too much. So they rather put up with a mild, quiet, gentle pop when first powered up. For example, McIntosh prefers the use of what they call the 'autoformer" (for other reasons), that many of us, e.g., irv, don't necessary like. You don't have to like Anthem's approach. If you insist in calling design choices based on individual manufacturers own belief as "defective" because you don't agree with or like their choices, then okay, I won't debate you because that's you opinion.



In case you missed his most recent posts, he said he would keep the amp. I have the impression that's because he now has the information he needs, and made his informed decision. We may not all agree with his decision, but it is his to make. All we can do is to provide him with information we wish to share, even offer our opinions, and I believe we have done so.

Yes decission was made and was informed thanks to you guys. Lets see how it goes. For now everyone in my family approved new amp from sound quality perspective. They noted that sound is now richer than it used to be (with Yamaha a860). I know there is another thread on when you need to go separates. This might be another reason. Though it hard to measure. But when 4 people in your family say basically the same in different words it makes me think it is not placebo this time.

Regarding pops. I ordered a box with manual switches and bunch of banana speaker female connectors. Will diy it to disconnect speakers before the amp making sure there is no any actual music comming to the amp input by that time. I dont mind doing this manually. Anyway you need to insert/remove cd or dvd into/from the player. So just one more step. Switching on will be similar except the sequence will change.

 

[Jparker82]

Hi,

I bought MCA 525 recently and the first thing i noticed is a noticable pop in speakers when switching amp on and off. This happens even if nothing is connected to the amp. After that i measured dc voltage on speaker output and noticed that when i switch amp on, dc voltage goes up to about 0.5-0.6v dc and then goes down to 10-20mv. When I switch the amp off, there is another pop and this time speaker cones go forward and stay in that position for about 2 seconds, then go back. But even after switching amp off i can see about 0.5v DC in speaker outputs for quite a long time (at least some minutes).

Anthem dealer says there is nothing to worry about. But I don't see the same with my Yamaha a860 and Monolith 5 while doing the same test.

My question is is that normal and safe for speakers? I got ProAc 148s front and 118s surround.

I bought the AVM 60 and two MCA525s over the weekend. I'm not getting any popping at all. Just fantastic sound.

 

[lovinthehd]

Yes decission was made and was informed thanks to you guys. Lets see how it goes. For now everyone in my family approved new amp from sound quality perspective. They noted that sound is now richer than it used to be (with Yamaha a860). I know there is another thread on when you need to go separates. This might be another reason. Though it hard to measure. But when 4 people in your family say basically the same in different words it makes me think it is not placebo this time.

Regarding pops. I ordered a box with manual switches and bunch of banana speaker female connectors. Will diy it to disconnect speakers before the amp making sure there is no any actual music comming to the amp input by that time. I dont mind doing this manually. Anyway you need to insert/remove cd or dvd into/from the player. So just one more step. Switching on will be similar except the sequence will change.

One of the least useful metrics is what your family thinks they're hearing with your biased setup.

 

[Andrein]

One of the least useful metrics is what your family thinks they're hearing with your biased setup.

For me not. Anyway i rely most on what i hear. There is no bias. If mca 525 sounded badly, it would go back to the dealler next day. Same as emotiva xpa 5.

 

[PENG]

I bought the AVM 60 and two MCA525s over the weekend. I'm not getting any popping at all. Just fantastic sound.

Not surprising, according to their website:

"The new generation of MCA Amplifiers uses of Anthem’s years of experience to “engineer out” common amplifier gremlins. Consequently, we’ve removed output relays, so the signal path has absolutely no moving parts."

"Power-on inrush current has been minimized to reduce line disturbances and stress on internal components. "

Note: minimized, not eliminated..

So if there is still any such "pop" I would expect it to be a very soft one and may only be audible in a quiet room, with sensitive speakers and one really tries to listen for the noise. By following the rule of power amp on last and off first, I don't see any issue with the MCA in this regard though I do prefer mine that is the older version.

 

[PENG]

For me not. Anyway i rely most on what i hear. There is no bias. If mca 525 sounded badly, it would go back to the dealler next day. Same as emotiva xpa 5.

The Yamaha RX-A860 is not really design for 4 ohm speakers such as yours unless you listen at relatively low spl, sitting not too far from them.

 

[PENG]

One of the least useful metrics is what your family thinks they're hearing with your biased setup.

IMO, he seems to have the preconceived notion that an amp with specs 0.001% THD amp (on paper) is going to sound better than one with 0.01% (again, just on paper), so that alone may have some effects. That being said, his speakers are 4 ohms nominal, though sensitivity is decent, could have played a part too, depending on other factors including impedance dips, room size, how loud he listens to and sitting distance etc.

 

[Andrein]

I listen to at -25db in average. I heard distortion during peaks. Prob +20-25db
Hence we are talking about ref revel. Dont think a860 will still have 0.01 there. Might be well 0.5 or even 1%. Also my surround speakers have sensitivity 88.5db/8ohm, front ones 91db/4ohm. Not sure i can hear any pop from surround speakers at all or it is very quiet.

 

[PENG]

I listen to at -25db in average. I heard distortion during peaks. Prob +20-25db
Hence we are talking about ref revel. Dont think a860 will still have 0.01 there. Might be well 0.5 or even 1%. Also my surround speakers have sensitivity 88.5db/8ohm, front ones 91db/4ohm. Not sure i can hear any pop from surround speakers at all or it is very quiet.

Just a couple points on the distortions thing:

- Your speakers very likely have distortions of over 1%, probably well over that at the low and high ends.
- I hope you are not using the RX-A860 as preamp for the MCA525, if you do, be aware that the MCA525 needs 1.5V to achieve its rated output of 225W, at that point the RX-A860's output would begin to turn nasty So if you believe your speakers actually would draw close to, or exceed 225W during peaks of the music you listen to, then you can forget about 0.001% or even 0.1% THD during such peaks. Given that in the audio signal chain from the source to the speakers, the amplifier's distortions are no where near being the bottleneck, you wonder why some of us have hard time understand why the difference in the 3rd or even 2nd decimal point is so important to you.

http://www.audioholics.com/av-receiver-reviews/yamaha-rx-a860/measurements

 

[slipperybidness]

Just a couple points on the distortions thing:

- Your speakers very likely have distortions of over 1%, probably well over that at the low and high ends.
- I hope you are not using the RX-A860 as preamp for the MCA525, if you do, be aware that the MCA525 needs 1.5V to achieve its rated output of 225W, at that point the RX-A860's output would begin to turn nasty So if you believe your speakers actually would draw close to, or exceed 225W during peaks of the music you listen to, then you can forget about 0.001% or even 0.1% THD during such peaks. Given that in the audio signal chain from the source to the speakers, the amplifier's distortions are no where near being the bottleneck, you wonder why some of us have hard time understand why the difference in the 3rd or even 2nd decimal point is so important to you.

http://www.audioholics.com/av-receiver-reviews/yamaha-rx-a860/measurements

Right, that's the point. He is hung up on these THD numbers that he can't hear the difference between!

And the THD from his speakers is certainly several orders of magnitude greater than the THD from the amps.

Now, if he has a gain structure problem, as you have hinted at as a possibility, that is a differnt problem altogether.

 

[lovinthehd]

For me not. Anyway i rely most on what i hear. There is no bias. If mca 525 sounded badly, it would go back to the dealler next day. Same as emotiva xpa 5.

I meant bias in that you haven't done a proper A/B comparison.

If you're listening to music there is no particular "reference" level used, as there is in movies.

 

[Andrein]

Just a couple points on the distortions thing:

- Your speakers very likely have distortions of over 1%, probably well over that at the low and high ends.
- I hope you are not using the RX-A860 as preamp for the MCA525, if you do, be aware that the MCA525 needs 1.5V to achieve its rated output of 225W, at that point the RX-A860's output would begin to turn nasty So if you believe your speakers actually would draw close to, or exceed 225W during peaks of the music you listen to, then you can forget about 0.001% or even 0.1% THD during such peaks. Given that in the audio signal chain from the source to the speakers, the amplifier's distortions are no where near being the bottleneck, you wonder why some of us have hard time understand why the difference in the 3rd or even 2nd decimal point is so important to you.

http://www.audioholics.com/av-receiver-reviews/yamaha-rx-a860/measurements

Saw the above page. And i think i mentioned a couple of times already that with mca 525 i cant hear obvious distortion on exactly the same songs at exactly the same moments where i heard something like sign of clipping with a860 only. Also i am not going to use all 225w. They wont be required given high sensitivity of my speakers and the fact that there are just 4 channels will be used and all "small". Anyway right now i like what i hear more than i had before including mca 525 into the chain. If i notice any sign of clipping i will change av receiver.

 

[Andrein]

I meant bias in that you haven't done a proper A/B comparison.

If you're listening to music there is no particular "reference" level used, as there is in movies.

I am happy with what subjective comparisson i did between xpa 5, monolith 5 and mca 525. Monolith and anthem sound more or less the same to me. Both are class ab. Xpa 5 is class d or h and to me dound much worse. I just did not wont to experiment with class d amps when i had good examples of ab amps. That is all.

I meant that during some songs peaks can be 20db or more. And this is where i heard some clipping with pure a860.

 

[Andrein]

Right, that's the point. He is hung up on these THD numbers that he can't hear the difference between!

And the THD from his speakers is certainly several orders of magnitude greater than the THD from the amps.

Now, if he has a gain structure problem, as you have hinted at as a possibility, that is a differnt problem altogether.

I know that speakers generate normally more distortion than amps. Normally!!! Looks like in my case during the peaks a860 was creating that critical mass of distortion which made the difference. This explains why with mca 525 it is cleaner now. Now all heavy lifting is work for mca 525. And even with a860 weak pre outs it seems to working better.

 

[sterling shoote]

Saw the above page. And i think i mentioned a couple of times already that with mca 525 i cant hear obvious distortion on exactly the same songs at exactly the same moments where i heard something like sign of clipping with a860 only. Also i am not going to use all 225w. They wont be required given high sensitivity of my speakers and the fact that there are just 4 channels will be used and all "small". Anyway right now i like what i hear more than i had before including mca 525 into the chain. If i notice any sign of clipping i will change av receiver.

Just a anecdotal thought about clipping, I've powered my JBL L100t3's with a 50 watt amp, a 100 watt amp, a 200 watt amp, a 300 watt amp, and now, I'm using a 5 channel 100 watt amp to power them. I've never felt under or over powered with any of these amps so far. No clipping ever, even at levels beyond what sounds life like. On the other hand, my sub appears to need some power. I tried a 100 watt stereo amp operating in bridged mode for 300 watts, but that was not enough to play at realistic levels without some clipping. Clipping BTW on a sub sounds like someone pounding a sledge hammer on a 4 inch steel pylon. I installed another amp, 200 watts stereo bridged for about 570 watts, and now no clipping on music or movies played at what seems to be a realistic level. At any rate, as I understand it, about 10 watts is all that's necessary on most music, most of the time, although I've never had an amp with such power.

 

[PENG]

Saw the above page. And i think i mentioned a couple of times already that with mca 525 i cant hear obvious distortion on exactly the same songs at exactly the same moments where i heard something like sign of clipping with a860 only. Also i am not going to use all 225w. They wont be required given high sensitivity of my speakers and the fact that there are just 4 channels will be used and all "small". Anyway right now i like what i hear more than i had before including mca 525 into the chain. If i notice any sign of clipping i will change av receiver.

The sensitivity of your main speakers are not "high", I would say just average. 91dB/1W/1m is like 88db/2.83V/1m for a 4 ohm nominal speaker. The @2.83V spec is preferred because then you can compare without having to adjust for the impedance.

 

[Andrein]

Right. Anyway. Lets see. If any problems i will replace a860 with a1060. But cant see any problem so far.