Just got the XPA-100 - amazing amps!

[lionear]

I'm the happy owner of a pair of XPA-100 amps.

The sound has changed quite a bit as they break in. My CD player and tuner have been keeping them busy all day and night. They have followed what I think is a usual route as far as break in is concerned. When first switched on, they give a hint of their quality. Then they sound worse, as the break in process sorts itself out. Finally they start to sound their best. So far, I'm surprised how quickly the Emotiva's have broken in and are past the "worse" stage.

I'm amazed by their performance. Crystal clear highs, great midrange, deep bass, speed, fantastic micro and macro dynamics, wide soundstage and oodles of depth. It's amazing how the amps have disappeared - they're not calling any attention to themselves and just letting the music through. I'm also amazed how neutral they are - neutral like the best Audio Research.  And by their "composure" - each melodic line is rendered faithfully even though the music can get complex and loud.  It's incredible how I can pick out each backing vocal from the main voice.

I've been using tube gear for the last 15 years and I'm quite floored by how good the Emotiva's sound.  Given the price - it's utterly fantastic.   There are areas where they sound different from my previous gear, but in every case, I can see that the Emotiva's are more accurate, more in control, less distorted.

I've found that:
- they do need to be plugged directly into the wall socket, and not to a filtering powerstrip (like Monster Power Center).
- the sound is degraded when using the stock power cords.  I'll go back to the cords later to verify this.
- they also seem to like to be resting on something very hard. I first had them on the carpet but putting them on marble tiles makes a huge difference in the focus and soundstage.
- flipping the switch to set the blue LED off improves the sound quite a bit.  It's hard to describe the effect - but the sound seems more "whole" when it's off.  I'll have to revisit this to see if it was just because of the breaking in.
- they do not like anything on them (nothing heavy like a VPI Brick, and nothing light like a bit of paper).

Would anyone care to share other set-up experiences/optimization tips?

Also, any views on which input is better - balanced or RCA?

[garbulky]

Dec 13, 2013 19:09:30 GMT -5 lionear said:

I'm the happy owner of a pair of XPA-100 amps.

The sound has changed quite a bit as they break in. My CD player and tuner have been keeping them busy all day and night. They have followed what I think is a usual route as far as break in is concerned. When first switched on, they give a hint of their quality. Then they sound worse, as the break in process sorts itself out. Finally they start to sound their best. So far, I'm surprised how quickly the Emotiva's have broken in and are past the "worse" stage.

I'm amazed by their performance. Crystal clear highs, great midrange, deep bass, speed, fantastic micro and macro dynamics, wide soundstage and oodles of depth. It's amazing how the amps have disappeared - they're not calling any attention to themselves and just letting the music through. I'm also amazed how neutral they are - neutral like the best Audio Research.  And by their "composure" - each melodic line is rendered faithfully even though the music can get complex and loud.  It's incredible how I can pick out each backing vocal from the main voice.

I've been using tube gear for the last 15 years and I'm quite floored by how good the Emotiva's sound.  Given the price - it's utterly fantastic.   There are areas where they sound different from my previous gear, but in every case, I can see that the Emotiva's are more accurate, more in control, less distorted.

I've found that:
- they do need to be plugged directly into the wall socket, and not to a filtering powerstrip (like Monster Power Center).
- the sound is degraded when using the stock power cords.  I'll go back to the cords later to verify this.
- they also seem to like to be resting on something very hard. I first had them on the carpet but putting them on marble tiles makes a huge difference in the focus and soundstage.
- flipping the switch to set the blue LED off improves the sound quite a bit.  It's hard to describe the effect - but the sound seems more "whole" when it's off.  I'll have to revisit this to see if it was just because of the breaking in.
- they do not like anything on them (nothing heavy like a VPI Brick, and nothing light like a bit of paper).

Would anyone care to share other set-up experiences/optimization tips?

Also, any views on which input is better - balanced or RCA?

I'm not sure how these things improve the sound. But what the hey... I won't say no to something I haven't tried. Congratulations on your purchase. I've heard the UPA-1's and they are nice amplifiers. I'm glad you are enjoying it!

So a tweak that worked for me was was leaving the amps turned on. They sound better the longer they are left on.

[Deleted]

I received mine a few weeks ago and can report similar findings re the 'burn in' differences but not with things on top nor needing direct to power outlet(however, I am in Oz and we have 240v ac so maybe....?)

Anyway, I absolutely love them!

They get better and better - much detail and elegance showing already - will review in the new year as I'm away for a few weeks (dang - just when I was getting excited I'm dragged away to a free holiday by the sea in a swanky apartment, such sacrifices.)

[Boomzilla]

Hi lionear -

How long did the break in take? (How long for the initial "could be good?" How long for the "decline in quality?" And when did the "starting to sound amazing" point come?)

I have also noticed that power conditioners are no friend to good amps. In fact on at least one of my tube amps (Rogue Tempest Magnum), the strip actually caused noise in one channel.

It's NEVER a good idea to put a heat-generating amp on carpet - it can interfere with cooling.

I've found no difference in power cords on the XPA-2 between the stock cord and the (shielded) X-series power cords.

With the music cranking, put your fingertips on the top of the amp. Feel any vibration? If yes, put a small weight to keep the chassis from dancing with the music. If not, then no worries, IMHO.

Enjoy those amps - I've heard they're something!

Merry Christmas - Boomzilla

[creimes]

Very nice to hear a positive review of the XPA-100, there had been one here who didn't like them that much and I think it scared everyone haha, but if they are any bit as good as the UPA-1's they will be excellent amplifiers for sure, enjoy the new gear.

Chad

[lionear]

Dec 17, 2013 22:23:57 GMT -5 Boomzilla said:

Hi lionear -

How long did the break in take? (How long for the initial "could be good?" How long for the "decline in quality?" And when did the "starting to sound amazing" point come?)

I have also noticed that power conditioners are no friend to good amps. In fact on at least one of my tube amps (Rogue Tempest Magnum), the strip actually caused noise in one channel.

It's NEVER a good idea to put a heat-generating amp on carpet - it can interfere with cooling.

I've found no difference in power cords on the XPA-2 between the stock cord and the (shielded) X-series power cords.

With the music cranking, put your fingertips on the top of the amp. Feel any vibration? If yes, put a small weight to keep the chassis from dancing with the music. If not, then no worries, IMHO.

Enjoy those amps - I've heard they're something!

Merry Christmas - Boomzilla

Hi there.

I'd say the break-in period varies with different gear.  Some gear take a very long time - I think HP once reported that his Audio Research SP-9 was still breaking in after one year!  My preamp took about 4 months.

As for the Emotivas, they came one week after Thanksgiving.  The initial "this is probably going to be very good" lasted about 2 days.  And then one week later, there was some peakiness in the female vocal/piccolo range.  (I think the reviewer of the XPR-1 amp in some magazine said the same thing.)  Nothing objectionable but a character, non-the-less.  There was also a bit of dynamic constriction (in micro and macro dynamics) creeping in.

However, that peakiness cleared out over the next two weeks.  I've played them pretty much continuously throughout the day.

Right now, all the frequencies are sounding very, very good and well integrated with each other.  There was one issue that came up - the overall sound started to sound a bit "metallic" - the National guitar on Dire Straits "Money For Nothing" sounded a bit too metallic and Mark Knopfler's voice was also too "nasal".  I decided to move the speakers out about 10mm (1/2 inch) off the back wall (may be a bit more) and that solved it.  The overall soundstage has opened up.  I suspect that the speakers had to move because there is so much more upper-mid and treble music coming through now.  The amps are not bright - my previous gear rolled off the top-end.  With the Emotivas and the new speaker position, I can get a much better image in the centre and I can follow the violins at centre-left so much better.  Now the midrange is like the midrange on the (good old) Quad ESL.

(Funny thing about the "metallic" sound.  Years ago, I heard some Wilson Audio speakers and I hated it because it sounded so…. metallic.  May be they just needed to be moved a bit more off the back wall.)

Initially, there was indeed a little vibration in the top cover. I thought, "Oh well, it's just a $300 amp." I tried to tame it with a VPI brick (very heavy) but that was a disaster. I then stuck a small paper label on the midpoint of the cover. This sucked out a lot of energy and detail from the top-end. But as the amps have broken in, and now that they're resting on the marble tiles, the vibration has gone.

Two things that may still need a bit of break-in: macro and micro dynamics.

I've never heard the opening of Dire Straits "Money for Nothing" get louder in so many gradations - kudos to the Emotivas!  However, at the very end, the dynamics seemed to be rolled off just a little bit.  Everything still hangs together very well through the loud passage - so the amps were not in distress - and this may change with more break-in.  (Then again, it could be my speakers…)

And as far as micro dynamics is concerned, I can hear this getting better and better.  I think this is one area that tube gear has (in the past) been better than transistor gear.  It's already good enough - but I think this may be better over time.  Then again, may be my old tube gear was exaggerating the micro dynamics just a little bit.  We'll see.

I'll go back to the stock power cords at some point and see how they sound, and I'll switch the LED back on.  But right now, I'm having too much fun!

PS: Years ago, HP reviewed some Mark Levinson amps.  He tried them at 120V and 220V and he said that they sounded better at 220V….

[Boomzilla]

Thanks, Lionear - I'll leave mine on continuously for a few weeks & see what happens.

[Boomzilla]

I'm very, very curious to see how my XPR-2 amp may change (if at all) by being left on continuously. I know that my friend, who has been an audio salesman all his life thinks it best to leave solid state equipment on continuously. He claims that the equipment sounds better that way. I've never previously left my equipment on when not in use. It just seemed a waste of electricity to me, and the equipment lighting was a constant reminder that I was wasting power for no good purpose. With my current equipment, however, the displays can all be turned off and the irritating reminder of panel lights is removed.

The U series amps that you own have been amazing values in my experience. My friend, Garbulky, has a UPA-2 that sounds as detailed and delicate as any amp I've ever heard. The X series amps, in Gar's opinion sound faster and have more dynamics. I concur. The XPR series amps, to my ears, and without significant break in, sound more like the UPA series than the XPA. They have that detailed and delicate sound but with deeper bass extension & control. If I had a single criticism of my XPR-2, it would be that the dynamics are also more like the U series than the X series amps. I'm hoping that some burn-in time will improve this.

Garbulky was kind enough to bring his Axiom M80 speakers to my house for an audition. At the time, the only amp I had in the house was my Crown PS-400. The combo had little bass and sounded bright with problems getting a solid center image. I think that if we had been listening to the XPR-2 instead of the Crown, it would have provided a "night and day" difference with Gar's speakers. The Crown is very unhappy with 4 ohm loads (which Gar's speakers are). The combination has always resulted in sloppy bass with any four-ohm speaker hooked to the Crown. The Crown's strong dynamics in the midrange and treble were a poor match for Gar's slightly-forward sounding Axioms.

The Crown amp's shortcomings are the XPR-2's strengths. The XPR-2 doesn't care about impedance and sounds remarkably consistent regardless of the speaker impedance that it's driving. The XPR's slightly restrained dynamics would compliment the Axiom speakers' forwardness (as does Gar's own UPA-2). The XPR is also one of the best imaging amplifiers that I've ever heard, so it should image like a hologram with Gar's (already good-at-imaging) Axioms.

Therefore, my options appear to be: Wait a few weeks to see if the XPR-2's dynamics improve, or to experiment with speakers that are better matched to the XPR's strengths. Of the two options, the first will be the hardest for my nature to accept, but it is the least expensive and is highly likely to work. No improved dynamics by the end of January? Time to go speaker shopping!

Cheers - Boomzilla

[Deleted]

Boomzilla, what do you mean by "The XPR's slightly restrained dynamics."   I thought an amp with very high power would be very dynamic unless for some reason it had a extra slow transient response (not sure if that is the correct term for an amp).  I hope I'm using the correct amplifier terms since I don't get into the nitty gritty evaluation of sound differences like many amp audiophiles do.  Can this be shown on a test piece of equipment and can you provide an example of this from a review?  It would seem that any restraint in dynamics  that one could hear in an amp could be clearly demonstrated with test equipment.   To me restraint in dynamics would be the tendency of slowness in being able to instantaneously provide the full power needed by the source/speaker.  Test equipment is clearly superior to the human ear in detecting differences  such as in loudness.  A very simple example of this is when a person has set their relative speaker output levels by ear and perceives them to be at the same exact level.  An SPL meter can many times show they are off by 0.5 - 1.0 or even more.

[Boomzilla]

Hi Chuckie -

I suspect that if the XPA-2 and the XPR-2 were put on the test bench that they'd measure the same. Despite that, their sound is different. Garbulky's UPA-2 has a sweet, delicate sound. When we replaced the UPA-2 with the XPA-2 (same room, same speakers, same everything), the sound was "faster & brighter." Do the amps measure differently? Probably not. But in the room, they do sound differently from each other.

So it is with my XPR-2. In the area of dynamics, my XPR-2 is far more similar sounding to Gar's UPA-2 than it is to my XPA-2. There are differences, even from the XPA-2: The XPR sounds as though it goes lower in the bass (it doesn't, but it sounds that way), and has tighter bass control than the XPA-2. The imaging (center image, width, and depth) seem better with the XPR than the XPA. The XPA, however, trounces the XPR on dynamics. It isn't a huge difference, but it is an audible one.

So what specification should I look at that tells me how the amplifier will make the speakers image? What spec tells me how the amp will work with varying load impedances? What spec tells me how dynamic the amp will sound? There are currently no specs for these aspects of amplifier performance. Nevertheless, the differences are audible.

Many say "all amplifiers sound alike." With constant, 8-ohm impedances and high sensitivity speakers, the assertion is probably true. Vary the impedance widely (particularly in the downward direction), change the phase angles with complicated crossovers, or use low sensitivity speakers that require significant voltage and current from the amplifier, though, and differences become readily apparent. Can I "prove" those differences with current test equipment? No. This does NOT mean that the differences don't exist; it DOES mean that either we're measuring the wrong things or that we don't yet know how to measure those aspects of the amplifiers' performances.

Boomzilla

[jmasterj]

Dec 17, 2013 23:38:57 GMT -5 creimes said:

Very nice to hear a positive review of the XPA-100, there had been one here who didn't like them that much and I think it scared everyone haha, but if they are any bit as good as the UPA-1's they will be excellent amplifiers for sure, enjoy the new gear.

Chad

+1 I'm glad to see some positive reviews of the XPA-100 amps too. I can't wait till I get a chance to hear mine.

[Deleted]

Dec 20, 2013 8:48:43 GMT -5 Boomzilla said:

Hi Chuckie -

I suspect that if the XPA-2 and the XPR-2 were put on the test bench that they'd measure the same. Despite that, their sound is different. Garbulky's UPA-2 has a sweet, delicate sound. When we replaced the UPA-2 with the XPA-2 (same room, same speakers, same everything), the sound was "faster & brighter." Do the amps measure differently? Probably not. But in the room, they do sound differently from each other.

So it is with my XPR-2. In the area of dynamics, my XPR-2 is far more similar sounding to Gar's UPA-2 than it is to my XPA-2. There are differences, even from the XPA-2: The XPR sounds as though it goes lower in the bass (it doesn't, but it sounds that way), and has tighter bass control than the XPA-2. The imaging (center image, width, and depth) seem better with the XPR than the XPA. The XPA, however, trounces the XPR on dynamics. It isn't a huge difference, but it is an audible one.

So what specification should I look at that tells me how the amplifier will make the speakers image? What spec tells me how the amp will work with varying load impedances? What spec tells me how dynamic the amp will sound? There are currently no specs for these aspects of amplifier performance. Nevertheless, the differences are audible.

Many say "all amplifiers sound alike." With constant, 8-ohm impedances and high sensitivity speakers, the assertion is probably true. Vary the impedance widely (particularly in the downward direction), change the phase angles with complicated crossovers, or use low sensitivity speakers that require significant voltage and current from the amplifier, though, and differences become readily apparent. Can I "prove" those differences with current test equipment? No. This does NOT mean that the differences don't exist; it DOES mean that either we're measuring the wrong things or that we don't yet know how to measure those aspects of the amplifiers' performances.

Boomzilla

Thanks for the detailed reply.  I tend to be in the camp that would hear less sound differences than you, but I do believe there are differences, just that they tend to be exaggerated by many.  However, that is for another time.   I have read many of your post about amps and how they sound comparatively.  In this particular post your comment about restrained dynamics seems to move a way from strictly subjective sound opinions and thus caught my attention.  The very word dynamics in an amp to me means being able to deliver from minute amounts of power to near maximum power in a millisecond or whatever.  There is no common published spec as you request for this other than the power output.  You mention "brighter" and "bass control" that I'm not referring to in my question, but the term "faster" does interest me and it seems to be the same or similar as dynamics.  I was never into oscilloscopes (I was into telescopes but that was for eyeing the chick in bldg E, unit 4) or newer test amp test equipment, but it seems to me that amp dynamics that you seem to hear should be able to be measured as a function of the speed of the amp's ability to deliver massive amount of power and change from small amounts to large amount instantaneously and back down.

This is the essence of my inquiry/curiosity.  Is there an objective test method that can demonstrate any significant differences in speed/fastness/dynamic/etc. in power amps such as we are referring to here such as the UPA-2, XPA-2, XPR-2 or other brand amps?  


  

[garbulky]

Well if you are looking at "faster". To my ears, the XPA-2 was definitely faster than the UPA-2. It was pretty audible imo. According to Lonnie (so question him about the theory) it was due to the slew rate. I haven;t heard the XPR-2.

[Boomzilla]

Yes, the test is called "slew rate." Slew rate is defined as the maximum rate of change of output voltage per unit of time and is expressed as volts per micro second. Limitations in slew rate can cause distortion. So ultimately, slew rate measures how quickly the circuitry can react to changes in a drive signal. The problem with a slew rate measurement is that the test is performed into a fixed load resistor. We know how many different ways an actual loudspeaker load is NOT like a resistor...

Lots of things affect slew rate including the electrostatic resistance of the power supply capacitors, the amount and type of feedback used in the circuit, and the specific characteristics of the drive section and output transistors used.

Boom

And by the way, Chuckie, did you happen to take any PICTURES of the Building E, Unit 4 chick that you'd care to share?

And another postscript here - I listened this morning to the XPR-2 after leaving it and the Oppo on all night. HOLEY MOLEY, BATMAN - now that's a difference! Better dynamics, better imaging, and just a far more realistic sounding presentation of the music. Subjective? Yes. But I think that anyone could have heard a difference between what this rig sounded like yesterday when I first turned it on and now. I've also now abandoned (removed) the TOSLINK feed from the Airport Express to my Oppo, and I'm streaming directly from the source computer to the Oppo via ethernet. In theory, this should allow me to stream hi-def music. I'll test that theory this afternoon.

[wiskers]

Love my XPA-100's, I put them on their own 15amp circuit. The sound just keeps getting better and better.

[jmasterj]

wiskers,

Hi,

How long have you had your XPA-100's? Which source do you enjoy listening to the most, and why?

[wiskers]

I've had the XPA-100's about 6 months. I built myself a computer and use J River, my computer (HTPC) is hooked up via usb to a DC-1, through a XSP-1 for bass management. With JRiver I can listen to my music,internet radio and watch netflix. I also have my plamsa tv hooked up to DC-1 and use my system for movies and tv. I like to keep it simple.

[jmasterj]

wiskers,

So you don't use the ERC-2?

[lionear]

About keeping audio gear on all the time… I concur most heartily. As for the electricity bill…. just how much would that be?

How much of this is because of the Oppo being left on, as opposed to the Emotivas?

There's a school of thought that says electrical circuits undergo the most stress on power up and power down so leaving the gear on all the time may actually help the gear. My preamp does not have a power switch so it's on all the time. I've never had any problems.

If it feels cool to the touch or there's good ventilation even if it gets hot, then I think it should be fine to leave the gear on.

Micro dynamics and macro dynamics are, I think, two areas where tube gear may have a different characteristic than transistor gear. In my view, it's what makes tube gear sound so "musical" despite frequency roll-offs, 2nd order distortion, etc. It makes us forgive so much! Who knows, tube gear might even exaggerate this a little bit.

[mdanderson]

Can the XPA-100 amps be stacked on one another? If not, then would some rubber feet help with the air circulation? Thanks.