XPA-5 vs ATI 1504

[jjmatrix]

Hello everyone; I had a chance to A/B test these two amplifiers for a month, thanks to a friend willing to lend the ATI 1504 to me. This is a real-world test, meaning no $60k interconnects and expensive room-treatment. If you're still interested... by all means, read on :-)
In the red corner we have the XPA-5 weighting in at 73 lbs, while in the white corner, the challenger: ATI 1504 weighting 64 lbs.





I'll start with some background on ATI: Amplifier Technologies Inc. makes amps for Mark Levinson, Lexicon, Cary Audio, Theta Digital, B&K, etc, owning the later two. Not too shabby. Also, they've been in business for more than 40 years, and their products are designed and built in the US (California).

Next, I'd like to give you an idea about my personal preferences, as to better understand the results of this test.
Firstly, I like my music loud; I usually listen at around 90 dB, of course with certain exception. Secondly, I like my music "clean"; I simply hate distortions of any kind. As far as types of music, I pretty much listen to anything; of course, I have my favorite: Jazz.
As sources, I prefer two: hi-resolution digital and vinyl (I know, it sounds crazy to like opposites but what can I tell you?).

I would also like to mention that I do not pretend to be an audiophile or to have "golden" ears; my vocabulary is quite limited as well so you may find certain phrases/words not usually used in audio reviews. I'm just hoping to convey my personal findings about these two amplifiers.
Without further ado, let's start.

EQUIPMENT AND ROOM

AMPS: Emotiva XPA-5 and ATI 1504
Speakers: Axiom M80 v3 (400W RMS, 4 ohms, 95 dB Sensitivity, Freq Resp +/-3dB (Hz): 34 Hz – 20 kHz)
Sources:
Digital - PC >> J River >> HDMI >> UMC-1
Analog - Pro-Ject RPM 1.3 Genie Turntable >> Carver C-2 Phono Amp >> UMC-1
Interconnects: Home made/terminated with gold-plated connectors from Parts Express
Speaker cables: home made speaker cables (Bluejeans cables and gold-plated banana plugs)
Room: partially finished basement, 22 ft by 28 ft.


SPECS

Specification	ATI 1504	XPA-5
Channels	4	5
Power (all ch. driven)	150 @ 8ohm, 225W @ 4 ohm, 450W @ 8 ohm (Bridged)	200W @ 8 ohms, 300W @ 4 ohms
Power Bandwidth	-4 dB 3Hz to 50kHz	-3 dB 5Hz to 150kHz
Freq. Resp. 20Hz to 20 kHz	0 dB, -0.25 dB	0.05 dB
THD	<= 0.05%

[/td][td]<= 0.1%[/td][/td][/tr]
[tr][td]Signal to Noise Ratio[/td][td]>= 100 dB[/td][td]> 97 dB (@ 1W)[/td][/tr]
[tr][td]Full Power[/td][td]-[/td][td]111 dB[/td][/tr]
[tr][td]Gain[/td][td]28 dB [/td][td]32 dB[/td][/tr]
[tr][td]Damping Factor[/td][td]>= 1000[/td][td]-[/td][/tr]
[tr][td]Input Impedance[/td][td]28,000 ohms[/td][td]UnBal: 23,500 ohms. Bal: 33,000[/td][/tr]
[tr][td]Dimensions[/td][td]17"W X 7"H X 13"D[/td][td]17"W x 7" 3/4H x 19"D [/td][/tr]
[tr][td]Weight[/td][td]64 lbs[/td][td]72.6 lbs[/td][/tr]
[tr][td]Capacitance[/td][td]72,000 (18,000 per channel)[/td][td]60,000[/td][/tr]
[tr][td]Output devices[/td][td]6[/td][td]6[/td][/tr]
[tr][td]Made in[/td][td]USA[/td][td]China[/td][/tr]
[tr][td]Warranty[/td][td]7 years[/td][td]5 years[/td][/tr]
[tr][td]Price[/td][td]$1400 (late 90s)[/td][td]$900 (Sep 2012)[/td][/tr]
[/table]

ATI 1504 Topology: totally complementary from input to output. Using dual-complementary differential input stages, followed by full complementary push-pull pre-drivers. These in turn are direct coupled (all stages after AC. Coupled input are DC) to two push-pull drivers.
All stages up to this point are operated in true Class A. The drivers then drive the full complementary output stage consisting of 6 high-current transistors per channel.

Emotiva XPA-5 Topology: fully discrete, dual differential, high current, short signal path Class A/B.


EXTERIOR, FEATURES AND BUILD QUALITY

The pluses for ATI are:
- thicker steel case and HUGE radiators.
- bridgeable; extremely easy to set via back switches.
- better warranty.
- all fuses and control LEDs are accessible from the top panel.
- lower THD.
- higher S/N Ratio.
- more capacitance.

XPA-5
- 1 extra channel.
- XLR/balanced inputs.
- more power.
- 12v trigger.
- higher gain.
- heavier.


ATI: 1
XPA-5: 0
-----------------------
POWER HANDLING
For both amps, I was unable to detect any problems related to power, no matter how hard I tried; no sign of clipping, audible distortions or anything else.
I went to about 105 dB, which was very load in my room; unfortunately I didn't have more demanding speakers, as the Axioms, while at 4 ohms have a sensitivity of 95 dB and are not particularly hard to drive. In bridged mode, the ATI was significantly louder; my measurements showed a plus of 3-4 dB.

ATI: 2
XPA-5: 0
-----------------------
SOUND QUALITY
Lower end
ATI - A little deeper lower end, and to a small degree better mid-bass. Overall, I found it a tad "muddier".
XPA-5 - Tighter and more controlled.


ATI: 3
XPA-5: 1
-----------------------
SOUND QUALITY
Mids
ATI - Mellow and warm but not in a good way. While decent, definitely not one of the amps strength in my view.
XPA-5 - Sharp, very well defined and a lot more up-front. My "cup of tea".

ATI: 3
XPA-5: 2
-----------------------
SOUND QUALITY
Highs
ATI - Very good overall, and on the warmer side.
XPA-5 - Just a bit brighter than the ATI's, very clean.

ATI: 4
XPA-5: 3
-----------------------
CHANNEL SEPARATION
The XPA-5 is perceptibly better in this department; I could pinpoint at any time what instruments are more on the left side or the right. It appears to me that XPA-5 has a lower crosstalk threshold/value.

ATI: 4
XPA-5: 4
-----------------------
SOUNDSTAGE
This is where the XPA-5 shone IMO; way better instrument and voice placement. I've listened to a few hi-def pieces from Buena Vista Social Club that at high sound

levels, I felt put me in the middle of a small venue where I could tell how the musicians were placed on the stage.
If there is one phrase to describe the ATI sound, I would say that with a few exceptions, all instruments and voices were on the same plane field.

ATI: 4
XPA-5: 5
-----------------------
IMAGING
A lot harder to detect and understand; I hope that at least I've got the gist of it :-). What I looked at, was to be able to tell (or imagine) where the listener sits in respect to the orchestra, if the orchestra (for a live classical piece) was directly in front or below/above, and in another specific case, if the vocalist is moving around the stage.
This last piece gave me some hard time as I had to find a recording where I knew what was happening on the stage; I had a test album where while there wasn't any music, some talks continually while moving around: for example, he starts talking while 30 feet away form the mikes, and walks toward the listener within 1 foot. In another example, a barber is "cutting" the listener's hair clipping away form left to right, form back to front.
I literally closed my eyes and tried to decide if what I was hearing was "real"; as with the soundstage sound test, I found that the XPA-5 was closer to the "truth" than the ATI.

ATI: 4
XPA-5: 6
-----------------------

CONCLUSIONS

What I like about the ATI is the build quality, the feature of having all the fuses accessible with a control LED beside them, and saving the best for last, the bridging capability. This is an amazing feature in my book for may reasons: easily transform your system when the time comes (a party?) to get a lot more power, upgrading to more channels doesn't render the amp unusable, available in 6 channels as well with LOTS of capabilities (ex: bridge them into a very powerful 3 channel amp for the fronts while keeping the 1504 for the surrounds and backs in a 7.1 system).

All things considered (the ATI 1504 in very good shape is still popping up used for $600-$650) I believe that the XPA-5 outperformed the ATI 1504 where it counts: sound quality. I liked more the overall listening experience, the only thing missing for me was a deeper lower end, which of course can be easily fixed via tone controls, equalizer etc.

I hope you guys find this useful; thanks for reading!

[garbulky]

Nice review. How did you find it compared with the UPA-1's in terms of stereo performance?
It's pretty amazing that this thing is keeping pace and outperforming in areas a 2k amp.
I really like the detail of the m80's and bass extension. I'm glad you are a fan too

[briank]

Oct 1, 2012 10:34:21 GMT -5 garbulky said:

Nice review. How did you find it compared with the UPA-1's in terms of stereo performance?
It's pretty amazing that this thing is keeping pace and outperforming in areas a 2k amp.
I really like the detail of the m80's and bass extension. I'm glad you are a fan too

The discontinued AT 1504 retailed for $1395. There's better 5 channel amps than the XPA-5 but they all cost a lot more. The XPA-5 offers excellent value.

[jjmatrix]

Oct 1, 2012 10:34:21 GMT -5 garbulky said:

Nice review. How did you find it compared with the UPA-1's in terms of stereo performance?
It's pretty amazing that this thing is keeping pace and outperforming in areas a 2k amp.
I really like the detail of the m80's and bass extension. I'm glad you are a fan too

That would be my next review; I am more than curious how will the XPA-5 will fare presenting music vs UPA-1. And yes, I am absolutely in love of the M80s.

Brian nailed it: it's very, very difficult to find any other company that will approach the price/performance point of the Emo gear.

[jhayman]

Excellent presentation of your opinion jjmatrix..
Although I do like the look if the XPA-5 better than the ATI..
I do like how you can access the fuses easily as for bridging the XPA-5 does not but they have amps that do..
I find the ATI very old looking my buddy loaned me one of his Rotel 1080B amps and it looked like the ATI with the big healsinks on the sides..
Very retro IMO , I think today more and more manufactures are making astectically pleasing products that don't get hidden inside a Hide in wall rack system where you can't see all but the front of your $$$ purchase..

[sharkman]

Interesting review. I was wondering, is the Outlaw amp around 15 years old?

[jjmatrix]

Oct 1, 2012 14:28:07 GMT -5 jhayman said:

Excellent presentation of your opinion jjmatrix..
Although I do like the look if the XPA-5 better than the ATI..

Thank you; it looks ATI at the time was gunning for a pro-amp look that will also appeal to home listeners.

Oct 2, 2012 12:18:03 GMT -5 sharkman said:

Interesting review. I was wondering, is the Outlaw amp around 15 years old?

Also thank you; and yes, the amp is about 15 years old.

[paintedklown]

I just stumbled upon this thread.

Nice review, lots of details,and thorough information here.

Every time I read another users review, I always feel that mine pale in comparison.

Good read, thanks for posting your thoughts.

[jjmatrix]

Oct 3, 2012 3:34:43 GMT -5 paintedklown said:

I just stumbled upon this thread.

Nice review, lots of details,and thorough information here.

Every time I read another users review, I always feel that mine pale in comparison.

Good read, thanks for posting your thoughts.

Thank you; I simply had some time on my hands and I thought these 2 amps are in the same class which may be interesting to some readers,

[selkec]

Ati = ugly as hell

Emotiva= sexy

[jjmatrix]

Oct 3, 2012 6:20:30 GMT -5 selkec said:

Ati = ugly as hell

Emotiva= sexy

LOL! That sums it up pretty good.

[sharkman]

I've always found the Emotiva products(and I currently have 3) to be a tad blingy, but I guess beauty is in the eye of the beholder. The Outlaw stuff strikes a nice balance.

This review might not be an apples to apples comparison since the ATI amp is 15 years old. How much use has it had and how much abuse? Hard to say in the course of 15 years. Brand new ATI amps with 200 wpc have significantly bigger power supplies than the XPA series, it would be interesting to see how well the XPA-5 would do in a direct comparison.

Still, this review does show that the XPA-5 is no slouch with a 32db gain structure.