Emotiva UPA-500 Five Channel Power Amplifier Review

[PENG]

I'd have to disagree with this statement somewhat. I frequently see AVR's (and HTiB especially) advertised as a 500 watt receiver/system because the rating is 5 channels and 100WPC. As an example:

RXV371 | Yamaha 500-Watt 3D 5.1 Channel Home Theater Receiver | hhgregg

In all fairness, I believe it is the retailer and not the manufacturer that does this; however, it is easy to see where any reasonable person would presume a receiver could produce the spec with ACD.

Actually there is no disagreement in this regard because when I mention AVRs, in my mind (I know no one can read my mind) I am thinking mid range ones such as the Yamaha RX-A or V 2XXX, Denon AVR-3XXX and up. Also I said I had not seen many, but I have certainly seen some, just not too many, that advertise in ways that people could be misled.. And I always refer to the manufacturer's ads, not resellers.

You are so right about it is not the manufacturer who does this, not in this case but again I have seen some who does though.


The following is copied from yamaha.ca for the RX-V373:

Amplifier Section

Channel 5.1
Rated Output Power (1kHz, 1ch driven)
100W (8ohms, 0.9% THD)

Rated Output Power (1kHz, 2ch driven)
85W (8ohms, 0.9% THD)

Dynamic Power per Channel (8/6/4/2 ohms)
110/130/160/180W

Never said anything about ACD.

 

[nickwin]

This review is bunk.

"Emotiva rates the UPA-500 as follows:

• 80 watts x 5 continuous @ 8-ohm (0.01% THD)
  
  
• 120 watts x 5 continuous @ 4-ohm (0.01% THD)

Emotiva doesn't specify at what frequency they rate their power output, but I assume they mean 1kHz which is how most manufacturers specify all channels driven power claims. My measurements in this scenario verified Emotiva’s power claims but mine were higher in distortion which is likely due to the fact that Emotiva does their power tests holding the line voltage constant whereas we don’t."

Looking at the measurement data provided there is absolutely no indication that this amp will hit "120 watts x 5 continuous @ 4-ohm (0.01% THD)" at ANY frequency. A more realistic 4-ohm 1khz (0.01% THD) figure would probably be around 55-60 watts per channel ACD.

Ive been an Audioholics reader for over a decade, specifically because they seemed unbiased and generally got to the bottom of things and told you how it was but this is clearly not the case anymore. These guys are well aware that a 350VA amplifier isn't going to be a be able to put out 120x5 continuous ACD at any frequency or respectable level of distortion.

Im particularly bummed because I bought this amp based largely on this review. I needed 120 watts per channel into 4 ohms for this particular application and this amp clearly wasn't delivering it. Looked at the specs and I see why.

Read the fine print folks. Not sure there are any unbiased audio publications at this point.

 

[everettT]

So what was your testing methodology and equipment? I'm sure it wasn't an AP unit

This review is bunk.

"Emotiva rates the UPA-500 as follows:

• 80 watts x 5 continuous @ 8-ohm (0.01% THD)
  
  
• 120 watts x 5 continuous @ 4-ohm (0.01% THD)

Emotiva doesn't specify at what frequency they rate their power output, but I assume they mean 1kHz which is how most manufacturers specify all channels driven power claims. My measurements in this scenario verified Emotiva’s power claims but mine were higher in distortion which is likely due to the fact that Emotiva does their power tests holding the line voltage constant whereas we don’t."

Looking at the measurement data provided there is absolutely no indication that this amp will hit "120 watts x 5 continuous @ 4-ohm (0.01% THD)" at ANY frequency. A more realistic 4-ohm 1khz (0.01% THD) figure would probably be around 55-60 watts per channel ACD.

Ive been an Audioholics reader for over a decade, specifically because they seemed unbiased and generally got to the bottom of things and told you how it was but this is clearly not the case anymore. These guys are well aware that a 350VA amplifier isn't going to be a be able to put out 120x5 continuous ACD at any frequency or respectable level of distortion.

Im particularly bummed because I bought this amp based largely on this review. I needed 120 watts per channel into 4 ohms for this particular application and this amp clearly wasn't delivering it. Looked at the specs and I see why.

Read the fine print folks. Not sure there are any unbiased audio publications at this point.

 

[nickwin]

So what was your testing methodology and equipment? I'm sure it wasn't an AP unit

I didn't mean to imply that I did my own measurements, but even Audioholics own measurements don't support this claim.

Are you suggesting that its realistic for an amplifier with a linear PS of 350VA to output 600 watts continous 1khz (.1 THD+N)? Im not an electrical engineer so its very possible I am wrong on this, but I didn't think that was feasible. I thought ~80% efficiency would be a high estimate for this type of amp.

This amplifier uses one shared PS for all 5 channels and distortion is already up to .1% at 125 watts with only 2 channels driven. Where is this additional 350 watts going to come from?

Are additional measurements really necessary to determine that 125 watts continuous ACD 4 ohm (600 watts total) isn't feasible for this amp at any reasonable level of distortion?

 

[KEW]

Emotiva doesn't specify at what frequency they rate their power output, but I assume they mean 1kHz which is how most manufacturers specify all channels driven power claims. My measurements in this scenario verified Emotiva’s power claims but mine were higher in distortion which is likely due to the fact that Emotiva does their power tests holding the line voltage constant whereas we don’t."

Having to increase the distortion level by 100X to get 82W does seem rather extreme.
I would like to understand how this might be legit!
I know in the past there have been cases with larger amps like the XPA series, where the amp wants more current than the household wiring can deliver, and the measurements fell shy of the published specifications, but that would not be the situation in this case.

The way I see it is if Emotiva is using a measurement which results in a reduction of 100-fold in the distortion level from what we are likely to see in out own home, then they are using a bogus method.
If AH has abnormal issues with their line voltage, that should be corrected or more likely, we would be seeing repeated failures to meet specs.

It is also curious that CFP-BW was measured with only one channel driven. It seems like this is normally done with 2 channels driven!

 

[PENG]

I re-read that review and found nothing much wrong. As stated, the 1khz power sweep test was done to provide instant gratification to please print magazine readers and allow them to do apple to apple comparisons.

Of course you can't expect the 350va transformer to deliver 75wx5 continuously. It could however, sustain such output level for a short duration, hence the power sweep test. Remember transformers typically have tremendous short term overload capability with no long term bad effects.

In real world scenarios that amp can deliver as stated but really no better than any mid range avrs such as the Denon 3000 and Marantz 6000 series. For those who wants a real power amp, they have the xpa/xpr amps to please, but then why not step up to the Monolith amps?

 

[nickwin]

I re-read that review and found nothing much wrong. As stated, the 1khz power sweep test was done to provide instant gratification to please print magazine readers and allow them to do apple to apple comparisons.

Of course you can't expect the 350va transformer to deliver 75wx5 continuously. It could however, sustain such output level for a short duration, hence the power sweep test. Remember transformers typically have tremendous short term overload capability with no long term bad effects.

In real world scenarios that amp can deliver as stated but really no better than any mid range avrs such as the Denon 3000 and Marantz 6000 series. For those who wants a real power amp, they have the xpa/xps amps to please, but then why not step up to the Monolith amps?

The claim is :

"Emotiva rates the UPA-500 as follows:
120 watts x 5 continuous @ 4-ohm (0.01% THD)"


Continuous, not short term. The review goes on to say that there measurements "verified Emotiva’s power claims", but with higher levels of distortion. I don't see how this is possible with any level of distortion let alone a reasonable amount, say 1%.

Emotiva has always rated there amps ACD in the past.

 

[PENG]

The claim is :

"Emotiva rates the UPA-500 as follows:
120 watts x 5 continuous @ 4-ohm (0.01% THD)"


Continuous, not short term. The review goes on to say that there measurements "verified Emotiva’s power claims", but with higher levels of distortion. I don't see how this is possible with any level of distortion let alone a reasonable amount, say 1%.

Emotiva has always rated there amps ACD in the past.

My comments pertain to the AH review, not Emo's website data. I agree with you that 120WX5 coninuous @ 4 ohm is not possible, not even close. If they define continuous as using a continuous sine wave, instead of a short burst/pulse signal, then I supposed they could explain away their advertised specs. In that case, I can force myself to believe that such an amp can sustain at the 120W level ACD, if say for a few seconds or even a minute. Probably good enough in practice but not what I would consider a real power amplifier, but that's just my opinion.

 

[KEW]

My comments pertain to the AH review, not Emo's website data. I agree with you that 120WX5 coninuous @ 4 ohm is not possible, not even close.

nickwin's point is that the AH review claims their measurements verify Emotiva's spec's.
He's not disputing AH's measurements. Rather he is disputing their interpretation of those measurements!

 

[PENG]

nickwin's point is that the AH review claims their measurements verify Emotiva's spec's.
He's not disputing AH's measurements. Rather he is disputing their interpretation of those measurements!

You are right, I missed that one point. AH verified the 8 ohm rating but at higher THD. AH did not seem to have verified the 120Wx5 cont. claim, if they did, the did not show it in the table.

It is now clear to me the so called "continuous" simply meant using a continuous waveform such as a 1khz sine wave as oppose to a skinny peaky shaped pulse. It did not mean literally continuous, like in terms of time minutes, hours, forever, infinite...

 

[nickwin]

You are right, I missed that one point. AH verified the 8 ohm rating but at higher THD. AH did not seem to have verified the 120Wx5 cont. claim, if they did, the did not show it in the table.

It is now clear to me the so called "continuous" simply meant using a continuous waveform such as a 1khz sine wave as oppose to a skinny peaky shaped pulse. It did not mean literally continuous, like in terms of time minutes, hours, forever, infinite...

This is a word for word excerpt from the measurement section of the review:

"Emotiva rates the UPA-500 as follows:

• 80 watts x 5 continuous @ 8-ohm (0.01% THD)
  
  
• 120 watts x 5 continuous @ 4-ohm (0.01% THD)

Emotiva doesn't specify at what frequency they rate their power output, but I assume they mean 1kHz which is how most manufacturers specify all channels driven power claims. My measurements in this scenario verified Emotiva’s power claims but mine were higher in distortion which is likely due to the fact that Emotiva does their power tests holding the line voltage constant whereas we don’t."

I don't agree that "AH did not seem to have verified the 120Wx5 cont. claim". The excerpt above doesn't say anything about meeting specs at 8 ohms only, it just says it meets the specs, and it lists both.

The reason this bothers me at all is because this is exactly the kind of thing that AH called out in the past. They have always been vocal against inflated specs, especially in amplifiers. Thats what drew me to there publications in the first place! They called it how it was.

In this case they seem to be not only letting it slide, they are actually going along with it by giving the manufacturer specs there stamp of approval.

 

[PENG]

I don't agree that "AH did not seem to have verified the 120Wx5 cont. claim". The excerpt above doesn't say anything about meeting specs at 8 ohms only, it just says it meets the specs, and it lists both.

The reason this bothers me at all is because this is exactly the kind of thing that AH called out in the past. They have always been vocal against inflated specs, especially in amplifiers. Thats what drew me to there publications in the first place! They called it how it was.

In this case they seem to be not only letting it slide, they are actually going along with it by giving the specs there stamp of approval.

How can you disagree with me when I agree with you?

I said AH did not seem to have verified..........
Note: "did not" ..... So aren't we in agreement on that point?

 

[nickwin]

How can you disagree with me when I agree with you?

I said AH did not seem to have verified..........
Note: "did not" ..... So aren't we in agreement on that point?

Haha, Im confused now. I don't think we are in agreement but maybe Im misunderstanding your statement.

"AH did not seem to have verified...", the way I read that it sounds like your saying AH didn't verify Emotiva claims, correct? Yet the review literally says they "verified Emotiva’s power claims".

They didn't provide any measurement data that shows it, but they directly stated in writing that they verified the power output claims.

 

[PENG]

I think you are confused between what AH said, and what they have actually presented in the review. I thought I made it clear that I was referring to the test results they presented in tabulated form in that review, not what they said, or not said.. May be this can help clarify things a little more, I couldn't copy the table, but below were the test results in the table presented in the review:

# of CH Test Type Power Load THD + N
1 CFP-BW 117 watts 8-ohms 1%
1 CFP-BW 225 watts 4-ohms 1%
5 1kHz Psweep 75 watts 8-ohms 0.1%
5 1kHz Psweep 82 watts 8-ohms 1%
2 1kHz Psweep 125 watts 4-ohms 0.1%
2 1kHz Psweep 160 watts 4-ohms 1%
5 Dynamic PWR 125 watts 8-ohms 1%
2 Dynamic PWR 225 watts 4-ohms 1%

You can see that they did include the 82WX5 8-ohms, at 1% THD, but they did not include the ACD (5 channels) 4-ohms test results right? That's why I said they did not seem to have verified the 4 ohm ACD output rating. I have to use the word "seem" just in case there is a chance that they might have in fact done the verification for the 4 ohm ACD test as well but somehow failed to include the results in that table.

 

[PENG]

The reason this bothers me at all is because this is exactly the kind of thing that AH called out in the past. They have always been vocal against inflated specs, especially in amplifiers. Thats what drew me to there publications in the first place! They called it how it was.

In this case they seem to be not only letting it slide, they are actually going along with it by giving the manufacturer specs there stamp of approval.

I think your are being a little harsh. To be fair to AH, they did include some sort of disclaimer in the review, prior to presenting their tabulated test results. It said:

"1kHz Power Sweep vs Distortion (1kHz PSweep) - popularized by the print magazines, this is an instantaneous power vs distortion test at 1kHz. The problem with this test is it often masks slew related and or frequency response problems some amplifiers exhibit at the frequency extremes, and thus inflates the measured power results. It does provide an instant gratification # for consumers to argue over on the forums so we are now incorporating this test to please the masses."

 

[nickwin]

I think your are being a little harsh. To be fair to AH, they did include some sort of disclaimer in the review, prior to presenting their tabulated test results. It said:

"1kHz Power Sweep vs Distortion (1kHz PSweep) - popularized by the print magazines, this is an instantaneous power vs distortion test at 1kHz. The problem with this test is it often masks slew related and or frequency response problems some amplifiers exhibit at the frequency extremes, and thus inflates the measured power results. It does provide an instant gratification # for consumers to argue over on the forums so we are now incorporating this test to please the masses."

We are arguing semantics, I understand what your trying to say .

As far as being harsh your welcome to feel that way but thats not my intention. Im just trying to call it how I see it. Now Im being forced to repeatedly argue my point, which is fine, but its putting me on the defensive. My goal was simply to point this out. I would counter that you are being unfair to the consumer/AH reader by supporting these kind of inflated claims.

That disclaimer doesn't have any relevance here. All it says is that 1kHz PSweep can produce a higher measured power result than a full bandwidth sweep and that its popular with print publications for that reason. That means AH 1kHz PSweep should produce the same, similarly inflated numbers, but they didn't.

My issue here isn't whether or not the 1kHz PSweep is a good metric for amplifier power, the issue is that the manufacturer spec, whether its technically a 1kHz PSweep or 1khz continuous or something else, doesn't seem accurate. AH didn't provide any data to support those claims but they say in the review that they did verify them and they are more or less accurate. This is where I call BS.

FWIW I have emailed Gene about this before, I can't find the message so I can't give a direct quote, but his response was basically that ACD 4 ohm measurements are "unrealistic" (he used that word) so they don't do them. What I say to that is if 4 ohm ACD tests are so unrealistic doesnt that imply that the 4 ohm ACD manufacture specs are also unrealistic? If thats the case, then why does the review say this:

"My measurements in this scenario verified Emotiva’s power claims"

How can you verify the claims if you think the tests and the data they produce are so unrealistic that you don't even run them??? How can can the same power claim be simultaneously "honest" and "unrealistic"?

 

[everettT]

Ok since we are talking power requirements, what speakers are you driving?

 

[nickwin]

Ok since we are talking power requirements, what speakers are you driving?

BG Radia X3 (4) and a BG Radia X5. They are rated 4 Ohm nominal, 93Db@1m 2.83V.

 

[everettT]

BG Radia X3 (4) and a BG Radia X5. They are rated 4 Ohm nominal, 93Db@1m 2.83V.

Are you haveing problems driving them wo clipping?

 

[nickwin]

Are you haveing problems driving them wo clipping?

Yes, I seem to be, even though I calculated I should have been drawing under 120WPC. This is what lead me to read this review and the included measurement data again.

For the record though the reason I posted this was to point out that AH endorsed what seem to fairly inflated manufacturer power claims, not to troubleshoot my headroom problems (although Im happy to discuss that too Im always glad to get advice).

I just want others to be aware that AH might not be totally unbiased in this regard. You always need to do your homework as a consumer. I didn't read the fine print in this particular review and now Im paying for it.