Emotiva UPA-500 Five Channel Power Amplifier Measurements and Analysis
All measurements were conducted per the Audioholics Amplifier Measurement Standard using our Audio Precision APx585 8 Channel HDMI Audio Analyzer. When Emotiva found out we were using this test gear, they went out Nicky Santoro style (played by Joe Pesci) from Casino and bought the very same test gear. This is a considerable investment in test gear that no other home theater publication and only a select few consumer A/V manufacturers make, which shows how serious Emotiva is about amplifier design and testing.
I did some quick spot-checking on the UPA-500 amplifier gain structure to ensure it could be properly driven with a wide assortment of preamps or receivers. My personal criteria for amplifier gain structure is that it should be able to hit full power when driven with 2Vrms. The UPA-500 hits full gain much sooner per my measurements which confirm Emotiva’s claim of 850mV. Seeing how most budget receivers preamp outs cannot deliver a full 2Vrms, this extra sensitivity Emotiva employed makes a lot of sense. I measured 29.7dB voltage gain (8 ohm loaded) which was very close to Emotiva’s 29dB specification.
Signal to Noise Ratio
Emotiva UPA-500 SNR @ 1 watt (A-weighted)
Just like past UPA series amps from Emotiva, the UPA-500 exhibited a commendably low noise floor. At 1 watt, I measured 97dB (A-weighted) which is what Emotiva specs for this amp. If you want the un-weighted noise floor, you can subtract about 10dB from this measurement. At 117 watts, I measured 117dB (A-weighted).
Frequency Response
Emotiva UPA-500 Frequency Response @ Full Rated Power
It was no surprise to me that the Emotiva UPA-500 exhibited ruler flat bandwidth from 10Hz to 50kHz with a gradual roll-off of about -1dB at 80kHz which is the bandwidth limitation of my test equipment. Emotiva claims the -3dB is 70kHz but I suspect it’s a bit higher based on what I measured here. What I found quite remarkable was the very tight channel to channel frequency response deviation of +/-0.081dB at 1 watt and +-0.10dB at full power. This indicates very tight tolerances in parts selection and excellent overall engineering.
Power Measurements
Using our Audio Precision APx585 8-channel HDMI analyzer, we conducted a full barrage of multi-channel amplifier tests on Emotiva UPA-500. We tested power using three methods all of which were taken at < 0.1% THD + N:
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Continuous Full Power Bandwidth (CFP-BW) from 20Hz to 20Khz into 8 and 4-ohm loads (up to two-channels)
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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.
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Dynamic PWR - 1kHz CEA-2006 Burst Method testing. This is a dynamic power measurement adopted from the car industry similar to IHF method only a bit more difficult for an amplifier and more representative of real musical content.
Keep in mind most review publications don't do continuous power measurements and they usually publish power measurements into clipping at 1% THD + N. Our measurements are very conservative as we use a dedicated 20A line with no Variac to regulate line voltage. We constantly monitor the line to ensure it never drops more than 2Vrms from nominal which in our case was 120Vrms.
For more info on amplifier measurements, see: The All Channels Driven (ACD) Test
Emotiva
UPA-500 1kHz Power Test
Left
Pic: ACD, 8 ohms; Right Pic: 2 Channels driven, 4 ohms
Emotiva
UPA-500 Dynamic Power Test (1kHz)
Left
Pic: ACD, 8 ohms; Right Pic: 2 Channels driven, 4 ohms
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# 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%
Emotiva UPA-500 Power Measurement Table
Emotiva rates the UPA-500 as follows:
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80 watts x 5 continuous @ 8-ohm (0.01% THD)
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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. If you compare our power sweep results to the dynamic power results you get about 1.8dB of headroom for all channels driven into an 8 ohm load and 2.5dB of dynamic headroom into 4 ohms for two channels driven. The power supply exhibits good headroom to deliver quick bursts of dynamic power when the program material calls for it.
FFT Distortion Analysis
Emotiva
UPA-500 FFT Distortion Analysis
(left
image @ 1 watt ; right image @ full rated power)
I ran FFT distortion plots at 1 watt (left pic) and full rated power (right pic) to determine how clean this amplifier really is. At 1 watt, the spectral distortion wasn’t exactly stellar with the second order harmonic (9.55 + 66.58)dB being 76.2dB down from the fundamental or 100*alog^-1(-76.2/20) = .016%. At 106 watts, I observed (29.13 + 44.94)dBV being 74.1dB down from the fundamental or 100*alog^-1(-74.1/20) = .0040% The odd order harmonics start dominating as the amp starts hitting the rails and becoming slew rate limited at very high frequencies. These are decent measurements, but certainly not the cleanest distortion spectrum I've seen compared to some much higher priced well-executed designs.
Crosstalk
UPA-500 All-to-One Crosstalk at Rated Power
The UPA-500 exhibited very good channel to channel crosstalk performance, much improved over the older and more expensive UPA-7 actually. With all channels acting as the noise source or disturber, I measured each idle channel one at a time to determine the worst case channel to channel crosstalk. At 1kHz the UPA-500 yielded -85dB @ 1kHz and -60dB at 20kHz for its noisiest channel. I consider anything less than -40dB @ 10kHz acceptable so the UPA-500 met that minimum requirement with over 20dB to spare. With only 1 channel acting as the disturber, the adjacent channel produced -95dB at 1kHz and -70dB @ 20kHz, again very good results.
KEW;908917
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 [hhgregg.com]
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.
PENG;908916
Amps, yes but I have not seen too many AVR advertised their rated watts with all channels driven. I am sure some do but not many. From honesty stand point, I agree they should do what they say they can do though as Gene said it is not realistic. I also think it is not practical, border on stupid, to do say 80WX7 ACD instead of aiming to achieve 2X120W but only 60X7, as the latter will perform better in real life situations.
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 [hhgregg.com]
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.
sharkman;908886
Hi Gene,
If an amp is advertised at 80 watts by 5 channels, then it should be able to put out 80 watts x 5 channels to my way of thinking.
Amps, yes but I have not seen too many AVR advertised their rated watts with all channels driven. I am sure some do but not many. From honesty stand point, I agree they should do what they say they can do though as Gene said it is not realistic. I also think it is not practical, border on stupid, to do say 80WX7 ACD instead of aiming to achieve 2X120W but only 60X7, as the latter will perform better in real life situations.
sharkman;908886
Hi Gene,
What these ACD full bandwidth tests do is demonstrate whether the amp in question can do what the manufacturer says it can do, that's why I like them. I may be out of touch, but us little guys have no way of verifying what these manufacturers are saying their products can do. I like Reagan's old line, "Trust, but verify". If an amp is advertised at 80 watts by 5 channels, then it should be able to put out 80 watts x 5 channels to my way of thinking.
These amps may or may not be used with 4 ohm speaker systems, but Emotiva's speaker line is all 4 ohm. I don't know, however, if they recommend the UPA amps with their speaker lines.
No what a full bandwidth ACD test verifies is an unrealistic test condition that would never occur in real life. EVERYONE that does ACD testing does it at 1kHz. I do that too, but I also do full bandwidth for up to two channels per FTC standard.
Read: The All Channels Driven (ACD) Amplifier Test — Reviews and News from Audioholics [audioholics.com]
gene;908668
I do full bandwidth tests with 2CH driven something hardly anyone does. It's simply ridiculous to do full bandwidth testing with all channels driven.
Hi Gene,
What these ACD full bandwidth tests do is demonstrate whether the amp in question can do what the manufacturer says it can do, that's why I like them. I may be out of touch, but us little guys have no way of verifying what these manufacturers are saying their products can do. I like Reagan's old line, "Trust, but verify". If an amp is advertised at 80 watts by 5 channels, then it should be able to put out 80 watts x 5 channels to my way of thinking.
These amps may or may not be used with 4 ohm speaker systems, but Emotiva's speaker line is all 4 ohm. I don't know, however, if they recommend the UPA amps with their speaker lines.