Wow - XPA-1 monoblocks make a difference !

[jra]

So I previously was driving my 5.1 system via an XMC-1 into an XPA-5 (gen2). I upgraded my speakers (from Focal Electra BE1027's to Focal Sopra 3's), and they sounded great. But I decided to gamble on upgrading the amplification to see if I could get more out of them. I must confess I was a little dubious (current is current/electrons are electrons) on whether more powerful amps would have any effect.

Boy, was I wrong ! I finally got both my gen2 XPA-1's set up (after fun with UPS and a missing package :-) and the difference is really audible ! Now I'm not doing blind A/B tests (which means this is a subjective opinion, take it with the grain of salt it deserves :-), but my speakers now have that "showroom" sound.

I'm really pleased with the monoblocks. On the XPA-5 there was a really slight background hiss if I put my ear right up to the speakers with no source. Not annoying, but a data point. With the XPA-1's that's completely gone now - and the transients on music sound "punchier" somehow.

I know, I'm dumb - but better components really do make a difference ! Who knew :-).

I hope the new DR1's don't replace the XPA-1 gen-2's yet. Or maybe the DR1's will be better ?

[jra]

OH, the DR1's just went up. Should I have bought the new DR1's, or stay with the XPA-1 gen2's ? They're the same price - what do the Emo staffers think ?

[hemster]

I'm no Emo staffer but I've give you my 2 cents worth.

Hmm. Do you like the Class A sound? (for the first 60 Watts, XPA-1s will be in class A). I'm willing to bet the sonic signature is not that different, depending on your musical taste.

DR1s use SMPS whereas the XPA-1s are fed from a massive toroidal. You do get a bit more power from the DR-1 but not noticeably so.

If you're the type that craves the latest then get the DR-1s. Otherwise, sit back and enjoy the sound. Personally I would get the DR-1s for no other reason than the fact that Emotiva is now opting SMPS and if you do have issues later on, getting parts may be difficult. But then again, you have a 5 year warranty so I'm sure there's adequate inventory.

I didn't help much with a decision, sorry. That's your call.

Edit: If weight is a concern, get the DR-1s. 

[jra]

OK, being really dense here (I'm a software guy, not a hardware guy :-) - what is the difference between a SMPS and a toroidal power supply ? Is it really going to make a difference in the sound ? I was always of the opinion the electrons were electrons, but I was wrong about going from XPA-5 -> 2 x XPA-1's so I'm willing to be educated :-).

[hemster]

I sincerely doubt you'll notice a difference in sound. Torodial power supplies are behemoths and heavy. I had an XPA-5 and know it's heavy. My PA-750 is very heavy making it difficult to move, or ship if I had to. If I was choosing between the XPA-1 and XDR-1, I would choose the latter - for reasons other than sonic difference. That said, I'd be very happy with either decision. Class A sweetness if really nice!

[jra]

Well I've just got the XPA-1's in place, so I really don't want to swap them out unless it's for something better sounding. As you said, they're *heavy*. I'm not too worried about repairs etc. They're Emotiva's - Emotiva have *always* stood behind any product I've ever gotten from them.

[novisnick]

Dec 13, 2017 18:52:11 GMT -5 jra said:

Well I've just got the XPA-1's in place, so I really don't want to swap them out unless it's for something better sounding. As you said, they're *heavy*. I'm not too worried about repairs etc. They're Emotiva's - Emotiva have *always* stood behind any product I've ever gotten from them.

 
Heavy? Their not heavy! Should’ve got on board when I did! LOL 
99 lbs each! & <0 .0025%  THD + Noise

               

[pknaz]

I'm not a fan of the new XDR-1's for a really shallow reason, I think they're ugly compared to the XPA-1

I agree with others, I highly doubt you'd hear any quantifiable difference in the sound signature if you did a blind A/B test.

[jra]

I gotta admit, they do look extremely elegant on each side of the room, with the control to move the blue LED to the opposite side being the cherry on top. I'm extremely happy with them !

[Lsc]

Dec 13, 2017 22:39:28 GMT -5 pknaz said:

I'm not a fan of the new XDR-1's for a really shallow reason, I think they're ugly compared to the XPA-1

I agree with others, I highly doubt you'd hear any quantifiable difference in the sound signature if you did a blind A/B test.

The 60 watts in class A is nice. Unless that’s overrated, I think the XPA-1 gen 2 is superior. They may want to make a running change in the binding posts though - like the double wides.

[garbulky]

It's not your imagination.
I bought the XPA-1 gen 2 to keep a steady base for upgrading the rest of my electronics + subs.
To my shock, the DC-1 + XPA-1 gen 2 bought me improvements that I was hoping all those other upgrades would bring.
I just finished watching some Lake Street Dive's live performances and man these amps are everything Emotiva was after in top notch sound quality. They will shine with the kind of speakers you have. They hit higher than their $1100 price tag implies.
So here I am, perfectly happy with my system, not really saving up for further upgrades.

And yes class A does make a subtle but important difference.
If you look at the massive chassis, it is absolutely jam packed with components. From a massive amount of output devices, 1200 KVA transformer per channel, 180,000 mf capacitance, FULLY BALANCED, 2 ohm capable, 60 watts class A, 1000 watts @ 4 ohm oomph, and a power supply tweak for improved specs from gen 1, this is an amp WITHOUT COMPROMISE. Period. Even with its balanced architecture, its power suppy and power devices can handle 2 ohm loads (which is tough for balanced units as they see it as a ONE OHM LOAD).

I was worried that the slightly low SNR from the class A circuity would cause lower res sound. Not even close! The resolving capabilities got pumped up several levels as they took hold of the axiom m80's and shook them around.
Things like room dimensions of a recordings come through very well. Stunning stuff all around. You made the RIGHT choice.
Emotiva's new DR amps are pretty impressive, but even they are not the no compromise amp that the gen 2 XPA-1 is.
No class A, less capacitance, no torroidsal power supply, and from what I can see less output devices (though I don't have any confirmation on that). Still they are going to sound pretty freaking amazing with their 3kwatt power supply I have NO DOUBT. I'm just saying....you definitely didn't settle.
If you want to upgrade, Dan has repeatedly mentioned .... get two more for quad monoblocks. That's how they run them at their shows. At that rate your system will never leave class A and have oodles of control. If my AC and plug outlets had the capacity to deal with that heat and the louisiana summer, that's what I would do!

Also if you haven't already, adjust your speakers after the amp change. Even slight differences in toe in can make a difference. Congratulations on your purchase! Your amps will definitely scaleif you ever go higher up in the electronics ladder. I listened to Macintosh's ginormous solid state monoblocks - I think they are like 20 or 30k. Verdict....not an XPA-1 beater.

[leonski]

don't forget that in 'testing', that louder is nearly always preferred.

Level Matching is key in such tests.

The key is the First Watt and how good it really is.

[garbulky]

Dec 16, 2017 23:36:25 GMT -5 leonski said:

don't forget that in 'testing', that louder is nearly always preferred.

Level Matching is key in such tests.

The key is the First Watt and how good it really is.

I think level matching makes it very hard to tell meaningful differences.
For instance, I was able to hear the difference between DACs level matched at 0.5 db to each other. But it was very very subtle. I sure wouldn't have been able to tell it blind. I think the problem is the brain fills in the missing gaps when you hear two things mlost identical to each other.

I think a more useful measure is to use one for some time. Then switch and use the other one as normal. Then if you have the time switch back to the first.

[leonski]

No matter how you slice it, Louder is nearly always preferred. This masks real differences which you might otherwise perceive, or not.


Time? Can't argue with that. I had a 'D' amp which I was liking. It took quite a while and extensive experiments with speaker placement to finally figure the High Frequencies were disturbing in some fashion. I couldn't put my finger on it, except it seemed 'phasy', if that's even a word.
Replacement amps of less power actually are more musicallly satisfying. And speaker placement became MUCH less of a chore.
My new amps are considered a 'high bias' design so the first couple watts, at least, are biased to class 'A'.

[garbulky]

Dec 17, 2017 2:27:30 GMT -5 leonski said:

No matter how you slice it, Louder is nearly always preferred. This masks real differences which you might otherwise perceive, or not.


Time? Can't argue with that. I had a 'D' amp which I was liking. It took quite a while and extensive experiments with speaker placement to finally figure the High Frequencies were disturbing in some fashion. I couldn't put my finger on it, except it seemed 'phasy', if that's even a word.
Replacement amps of less power actually are more musicallly satisfying. And speaker placement became MUCH less of a chore.
My new amps are considered a 'high bias' design so the first couple watts, at least, are biased to class 'A'.

Interesting, which amps are those?

[leonski]

If you mean the amps I eventuallly Did Not like? 
a PSAudio GCC series Integrated.   The middle of the line, GCC250.   
5 inputs, one of which was balanced and an extra output to drive a pair of subs.   
No tone controls.   No processor loop.   It did have a small display.    And a useless and cheap remote.

The amp was essentially a PAIR of B&O 'ASP' modules and some proprietary input / switching circuitry.   
What PS called a Gain Cell is a pretty neat and I suspect UnFixable idea, it being a potted module.     

I finally figured out the problem.    'D' amps can be 'wide bandwidth' well beyond the limits of human hearing.    BUT they also have an output network called a Zobel which is how the amp
apparently removes all the HF switching noise which is all fairly high in frequency.   Maybe 400 to 500Khz.      Depends on the design and execution.    Bruno might do it differently.

Anyway, the Zobel introduces a Phase Shift in the upper octave of audible output.   Indeed, the output at 4 ohms was a fraction of a db down 20khz, but fell rapidly at higher frequencies.
This I THINK had an unfortunate interaction with the crossover of my speaker and how the panel is configured with tweeter either being to the inside OR outside edge (Experiment HERE).

It took me a long time to figure this out and I eventually sold the amp to a good home.

Attachments:

[garbulky]

leonski I had no idea PS Audio did a D amp. I meant to say what was your high bias amp you had in mind?

[leonski]

Parasound Halo amps are considered 'high bias'.      A23 which I have, not so much, but the A21 of 2x the power has first 10 or more watts in 'A'.    The JC-1 even more.

forum.audiogon.com/discussions/parasound-halo-jc-1-monoblock-amplifier

Just glance at the discussion about the JC-1

The JC-1 has a back panel BIAS switch for high / low level, which later appeared on some EMO G2 amps.   

For me and my budget (near-zero$$) the Parasounds are an 'end game' amp.    After or rather if/when I can go to a line-level biamp for my panels, that's gonna buy me maybe an additional 2+ db apparent power.
MiniDSP is on the list for this modification.   
Once amps are limitied to only those frequencies I desire be fed to my panels, that's IT.

[amped]

"...Emotiva's new DR amps are pretty impressive, but even they are not the no compromise amp that the gen 2 XPA-1 is.
No class A, less capacitance, no torroidsal power supply, and from what I can see less output devices (though I don't have any confirmation on that). Still they are going to sound pretty freaking amazing with their 3kwatt power supply I have NO DOUBT. I'm just saying...."

Just curious...How does anyone know how impressive the new DR.s are?  Has anyone heard them?  "No class A, less capacitance, no torroidsal [toroidal]  power supply, and from what I can see less output devices..." Sounds like a recipe for mediocracy I'm just saying... 

[leonski]

amped:
The reason switcher PS works at all is that it recharges the PS capacitors at whatever rate it runs at. FAR higher than 50hz or 60hz of 'linear' supplies. Up in the several HUNDRED KiloHz range. This means that even the slightest drop in capacitor voltage below PS voltage is
nearly Instantly dealt with. Not so much with a Linear supply which are typically much less well regulated. For a conventional Linear supply? Cap Recharge is done far less often and may be impaced by huge draws on the PS where the voltage drops. Capacitors will only recharge when
the charging voltage is higher than the voltage currently in the cap.

This is not to say I'm a big fan of Switchers. I'm not. I don't like the potential for noise at RF frequencies which can propagate everywhere and potentially impact the sound of the system.

One of the 'tricks' to output devices in an amp is to MATCH them. All parts have manufacturing tolerances for various measurables. If you can select parts with a very narrow range of measurements you improve the amps in general. I worked in a 'fab' which manufactured power
semiconductors and parts may be 'binned' when tested at probe. Matching output devices is a time-consuming and potentially costly operation.

Because of design requirements, Number of output devices is generally a Red Herring. Running high bias, you automatically need more or higher capacity devices. And the heatsink to 'cool it'.