Anthem STR Stereo Integrated Amplifier Preview

[PENG]

Wondering how much str is different from their MCA series.

Big difference, you know the STR is an integrated amp right? Aside from that, the power specs of the two are very similar. The STR has an encapsulated power transformer, look nicer but it doesn't mean it will translate into better specs, many higher end amps have non encapsulated types. The caps are the same, on the low side relative to other brand's amp within the same power output range. For less than half the price, I think the MCA225 paired with a preamp/DAC or AVR is a much better deal.

The STR power amp, for C$7499, is a little ridiculous I mean, think Bryston, Classe, McIntosh instead. In this case the specs and datasheet made it clear that the 400/600/800W, 8/4/2 ohm are for continuous into 2 ohms. Let's do some simple math here:

1. Calculate the current, assuming the load is purely resistive:

I^2X2 = 800W, (into 2 ohm resistive load), the current draw will be SQRT(800/2) = 20A per channel.

2. Calculate power input from the wall outlet:

Class AB amp efficiency is much lower than 100%, let's assume the Anthem amp is a highly efficient one, say 70% (overall including power supply losses) at rated load:

Input power = Output power/eff = 800WX2/0.7 = 2285W

3. Calculate transformer VA requirement:

For the amp to be rated continuous, assuming the transformer efficiency is 99% (that's being generous), the transformer VA rating would have to be 2285/.99 = 2,309 VA in order to produce 800W into each 2 ohm resistor. In reality, most loudspeaker's load will be reactive with average power factor of less than 1, that will drive the transformer VA rating even higher. For it to do 800W continuously into 2 ohms, each of the two toroidal transformer would have to be rated at least 1.2 kVA. They don't look that big at all, may be 850VA each at the most. The weight also does not seem commensurate with the claimed rated power output. The Anthem's own P2, rated only 325/500/675W 8/4/2 ohm weighs 75 lbs vs the STR's 60 lbs.

 

[PENG]

Just trying to understand what really the diff between mca and str is. It looks they sacrificed something for the dac and increased the price by 50 per cent. Maybe something improved. Did not compare spec line by line. But i think if you have a dac already, mca 225 is a better choise.

I agree 100%, but I do prefer the look of the STR, that obviously is subjective. I did compare their specs line by line. The MCA every bit as good, on paper anyway.

 

[Andrein]

I agree 100%, but I do prefer the look of the STR, that obviously is subjective. I did compare their specs line by line. The MCA every bit as good, on paper anyway.

Yeah str looks better and more modern. But otherwise it would be even more strange given the price.

 

[PENG]

Was looking at their printed doc that comes with my amp. No one channel statement. Same in pdf you can download from thei site.

I said under the tab specs, obviously on the website:

it says "Per Channel", not stated explicitly "One", or "ALL" channel so it is subject to interpretation.

Also, I have the MCA20, that is the predecessor of the MCA225, and the datasheet does show the rated output for 1 and 2 channel driven. That is, for the MCA20 535/410, 1/2 Channel, and for the MCA50, it was 535/340, 1/5 channel. Anthem appears to have gone backward in terms of providing honest specs.

By the way, are you concerned, or just curious? I hope you are just curious, as I am..

 

[PENG]

Yeah str looks better and more modern. But otherwise it would be even more strange given the price.

If you compare the power amp specs line by line, the MCA225 is marginally better, or negligibly better, just for the record. Funny you mentioned "strange". After taking a longer look I actually find the MCA more acceptable as a tough and serious looking power amp. The STR, okay it is integrated with DAC, looks a little too European and toy like to me.

 

[KEW]

Just trying to understand what really the diff between mca and str is. It looks they sacrificed something for the dac and increased the price by 50 per cent. Maybe something improved. Did not compare spec line by line. But i think if you have a dac already, mca 225 is a better choise.

It looks like they focused on improving profits with this model!

 

[Andrein]

Curious how anthem marketing team was thinking. Sure in terms of sq nobody will notice any difference. Dont know i feel these companies just getting a bit too hungry for money...

Regarding comparing ratings betwiin 525 and 50 is not accurate. Previously one tranformer handled front speakers and one back ones. Now 525 has a common tranformer pool which is used for all channels. Good idea as before back channels of the amp were under used. Now this extra power can be used for fronts during peaks.

 

[PENG]

Curious how anthem marketing team was thinking. Sure in terms of sq nobody will notice any difference. Dont know i feel these companies just getting a bit too hungry for money...

Regarding comparing ratings betwiin 525 and 50 is not accurate. Previously one tranformer handled front speakers and one back ones. Now 525 has a common tranformer pool which is used for all channels. Good idea as before back channels of the amp were under used. Now this extra power can be used for fronts during peaks.

There are pros and cons, some actually use one transformer per channel even for 5 channel amps. I have a Marantz MM8003 that has just one 1.2kVA for all 8 channels, and I like it that way. For 2 channel amp, I prefer true mono block design that uses one Tx for each channel, like my Bryston but again, always pros and cons.

 

[PENG]

It looks like they focused on improving profits with this model!

Right on!, I bet their marketing guys won this round, whereas the engineers did better on the MCA and P series rounds.

 

[KEW]

Right on!, I bet their marketing guys won this round, whereas the engineers did better on the MCA and P series rounds.

I wonder if the STR would be sold in the same shops as the MCA/P.
It may be they felt the market for the STR could bear a steeper markup with the image of an exclusive and exotic unit whereas the MCA would be sold in a more competitive market. I have no idea, but it is strange how drastic the difference in price is!

 

[PENG]

I wonder if the STR would be sold in the same shops as the MCA/P.
It may be they felt the market for the STR could bear a steeper markup with the image of an exclusive and exotic unit whereas the MCA would be sold in a more competitive market. I have no idea, but it is strange how drastic the difference in price is!

When I have some free time I will pay the dealer where I bought my MCA years ago a visit, to find out what the discount factor is for the STR. It is possible that their prices are more negotiable than the budget oriented MCA series.

By the way, I spent lots of time to search out the definitions of "continuous" power rating for audio amps. I did download all I could find, but one that is easy to read is in the TI article linked below:

http://www.ti.com/lit/an/slea047a/slea047a.pdf

On page 1, it says:

"For an audio signal, the voltage is in Vrms (root-mean-square), the power is referenced to a frequency of 1,000 Hz, and the load is usually referenced to a resistive load. Thus, the power obtained is the average power that the amplifier can sustain. The FTC requires further that the amplifier be pre-conditioned at one-eighth of rated total power output (for a multiple-output system, all channels are on) for one hour using a sinusoidal wave at a frequency of 1,000 Hz. The power spectrum measurement is then collected with two channels at maximum rated power over the audio frequency range of 20 to 20,000 Hz, in ambient still air of not less than 25°C, for the duration of not less than 5 minutes. Some manufacturers use an average power rating, but at a higher distortion ratio obtained by amplifying the original input signal to a level where clipping occurs. At 10% THD+N, the average power rating is higher than at 1% THD+N. For Texas Instruments PurePath Digital power-stage data sheets, both unclipped and clipped power ratings are measured."

So it's 5 minutes or longer according to this source. I read different duration from other sources, that also referenced FTC, EIA etc., problem is, for the same standard, there are different versions. I also focussed on those I could download for free. On of these days I would bite the bullet and purchase one or two just to satisfy my curiosity.

 

[Andrein]

When I have some free time I will pay the dealer where I bought my MCA years ago a visit, to find out what the discount factor is for the STR. It is possible that their prices are more negotiable than the budget oriented MCA series.

By the way, I spent lots of time to search out the definitions of "continuous" power rating for audio amps. I did download all I could find, but one that is easy to read is in the TI article linked below:

http://www.ti.com/lit/an/slea047a/slea047a.pdf

On page 1, it says:

"For an audio signal, the voltage is in Vrms (root-mean-square), the power is referenced to a frequency of 1,000 Hz, and the load is usually referenced to a resistive load. Thus, the power obtained is the average power that the amplifier can sustain. The FTC requires further that the amplifier be pre-conditioned at one-eighth of rated total power output (for a multiple-output system, all channels are on) for one hour using a sinusoidal wave at a frequency of 1,000 Hz. The power spectrum measurement is then collected with two channels at maximum rated power over the audio frequency range of 20 to 20,000 Hz, in ambient still air of not less than 25°C, for the duration of not less than 5 minutes. Some manufacturers use an average power rating, but at a higher distortion ratio obtained by amplifying the original input signal to a level where clipping occurs. At 10% THD+N, the average power rating is higher than at 1% THD+N. For Texas Instruments PurePath Digital power-stage data sheets, both unclipped and clipped power ratings are measured."

So it's 5 minutes or longer according to this source. I read different duration from other sources, that also referenced FTC, EIA etc., problem is, for the same standard, there are different versions. I also focussed on those I could download for free. On of these days I would bite the bullet and purchase one or two just to satisfy my curiosity.

5min is a quite a bit but if your speakers are really 2ohm in some ranges and you listen to them for hours then 5min is not enough. Though Anthem does not describe 2ohm as a special case and assume that people can use 2ohm speakers as normal. Though how many speakers dip to 2ohm?

I know that mine can go to 3.6ohm and 525 is just a bit warm after hours of listening at -15db.

 

[PENG]

5min is a quite a bit but if your speakers are really 2ohm in some ranges and you listen to them for hours then 5min is not enough. Though Anthem does not describe 2ohm as a special case and assume that people can use 2ohm speakers as normal. Though how many speakers dip to 2ohm?

I know that mine can go to 3.6ohm and 525 is just a bit warm after hours of listening at -15db.

To be clear, the article I linked only talked about how the power rating could be measured. I still am not sure what exactly Anthem meant be xxx watts continuously into X ohms blablabla...

Yes, even 5 minute is "quite a bit". No, I cannot think of any music or movie I have ever owned that would call for anything more than 50 W in my room for more than some seconds, let alone a full minute. I don't have any speakers that dip below 3 ohms either. It truly is just academic, except for people who would insist on cranking the volume know right up, put on their ear plugs to protect their hearing, and listen to highly compressed music "continuously" all day. If you sit within a few meters in a not too larger room, at -15, your wattmeter would register no where near even a few watts average with peaks to may be 30 to 50 watts, just my rough guess, but it can be easily calculated or just use an online calculator. Your 525 should be cruising at very low output level at extremely low THD, IMD etc.

 

[Johnny2Bad]

I know, that's why I called them out on this. Either they had a typo, or....well, really don't want to say, use your imagination..

Actually, if you read the data sheet it does not say how many channel, but under the tab "specs" (click on it), it does say:

POWER OUTPUT (PER CHANNEL)
(Continuous RMS, 20 Hz - 20 kHz, <1% THD)

So if they meant 600 W, one channel driven into 2 ohm, then it could be, still they should define "continuous", if they meant it literally, then it is still highly questionable. It is all academic though, most people plug their amp into a 15A or 20A circuit and don't push any more than a few watt average with much higher peaks depending on the music but still low enough for most mid range AVR, let alone a 225W Anthem amp.

C'mon, PENG, you're smarter than that. A "typo" or "lXXing"? I don't know what put the Bee in your Bonnet but maybe wait and see before the accusations come flying. There is about a zero chance these won't be reviewed with power testing.

 

[Will Brink]

Anthem is strengthening its presence in the two-channel audio space with the introduction of the STR Integrated Amplifier which they unveiled at the CEDIA 2016 Expo show. Built with high end components, a MC and MM phono preamp and high resolution 32-bit/384 kHz DAC, the STR is ready to meet your audiophile needs. Able to pump 600 watts into 2 ohm loads, it can also easily power the most demanding loudspeakers as well.

Looking to get your two-channel fix? Try Anthem!

Read: Anthem STR Stereo Integrated Amplifier Preview

Needs as full review! Like most Anthem products, seems hard to impossible to beat for the $ but now I'm curious to see someone actually test those claimed power ratings. Anyone do that yet?

 

[Will Brink]

C'mon, PENG, you're smarter than that. A "typo" or "lXXing"? I don't know what put the Bee in your Bonnet but maybe wait and see before the accusations come flying. There is about a zero chance these won't be reviewed with power testing.

2 years later, unless I missed it, yet to happen. I'm using an STR Integrated right now. Only had it less than a week. Steroephile did post bench numbers, but I'd like to see some more reliable like Gene test it:

Anthem Electronics STR D/A integrated amplifier Measurements

Sidebar 4: Measurements

www.stereophile.com

Thoughts on those numbers?

 

[Will Brink]

2023 and still nadda?

 

[gene]

2023 and still nadda?

Reviewed 5 years ago. Maybe search next time before ASSuming.

Anthem STR Preamp and Power Amplifier Review

The Anthem STR preamp and power amplifier emphasize fidelity first armed with the latest in 32 bit DSP, ARC room correction, and oodles of power reserves on tap. More details in our review so read on.

www.audioholics.com

 

[Will Brink]

Reviewed 5 years ago. Maybe search next time before ASSuming.

Anthem STR Preamp and Power Amplifier Review

The Anthem STR preamp and power amplifier emphasize fidelity first armed with the latest in 32 bit DSP, ARC room correction, and oodles of power reserves on tap. More details in our review so read on.

www.audioholics.com

Ummm, you sir may want to read the thread to which you responded before ASSuming. We are discussing the integrated amp (which I own and am a big fan of ....) vs the separates.

 

[Will Brink]

Here's the stereophile measurements for the integrated, which seems respectable:

Anthem Electronics STR D/A integrated amplifier Measurements

Sidebar 4: Measurements

www.stereophile.com

Thoughts/opinions on the measurements?