XDA-1 review vs Xonar Essence ST (very long)

[garbulky]

Update: In my original review, I mentioned that my headphone amp wasn't up to the task and did not sound very good through the xda-1. After looking at the specs of my headphone amp I decided that the amp was being overdriven by the XDA-1. A kindly forum member sent me a set of 12db RCA voltage attenuators. This allows me to turn my DAC to 80 for my headphone amp and closer to 80 for my upa-2 (reducing the impact of the lossy volume control). So I've been trying it out. I haven't had enough time to make a full evaluation. But from the onset I can see that there are some possible cons and benefits to this method some that you don't quite expect. It's a mixed bag but it does point me in the general direction to go to.
I will update as I form an opinion and get more info. I'm certainly enjoying my testing period.

[garbulky]

Well some more initial impressions on the voltage attenuator. It may be that the UPA-2 was being slightly overdriven as well! I have to do a bit more experimentation before I can be more sure of that. But that is certainly a surprise.

[garbulky]

Voltage attenuator update: Voices are easier to place. The trade off is that the sound signature has changed. The sound signature is now more similar to the asus xonar essence. The essence did better at conveying a sense of ambience, and I notice the improvement in ambience here as well with the attenuator. Bass impact is also increased. However 12 db may be a bit too much for the upa-2. I feel the treble is a little recessed making the sound stage feel laid back. A 6db may be a better compromise. I can't know for sure until I get the 6db version though.

[garbulky]

Update 9/2012 (warning! Non-scientific, subjective and unsubstatiated assumptions! i.e. I listened to the darn thing): I have been fiddling around with RCA voltage line attenuators for a while to get my headphone amp to play nice with my xda-1. It distorted before.

Well I decided to try it with my upa-2. I noticed a surprising difference. It was subtle. Before without the attenuators, as the volume increased, things felt a little harsh or compressed or strained would be the best way I can think of putting it. However everything felt very clear but at times not as realistic as I would have hoped.
So I used these voltage attenuators and I actually recognized a difference. Basically the sound signature changed. All this has to be kept in mind that the difference is very subtle. The treble was slightly laid back, the mid-range became more prominent and the bass became just slightly more undefined. Warmer would be the best way to put it.
Pros: Depth was easier to define and room ambience came through better. Voices sounded more like they were in the room than before.
Con: There was a slight loss in detail. Very powerful microdynamics were slightly dulled. Movies didn't sound as good. It felt like the upper bass was slightly too much.
Anyway, from what I gather voltage attenuators aren't supposed to change the sound so I was surprised that it did.
But then I came across this:
www.enjoythemusic.com/magazine/equipment/0803/rothwell.htm
While I don't agree with some of his descriptions especially the degree as I feel it's a very subtle change, I think it echoes a lot of my sentiments.

He brings up the issue with overloading power amps with pre-amps that push out a signal that's too powerful due to amps being driven to full power at low voltages. I have no data to back it up but I do wonder if this is what is happening. If so, that doesn't really make me very happy as I would think that emotiva's products need to work BEST with emotiva's products and if there is some input overload on the upa-2 then it is rather dissapointing.

I do want to mention (again) that I don't have any facts about this or the specs of the inputs and how things mess up if there's too much power or any proof of input overload or poorly matched emotiva parts. However, that's where I am leaning toward simply because of my experience.

My primary purpose was to allow the xda-1 to play at louder volumes to bypass the lossy attenuator's effect a bit better and so I was surprised when I noted the sound signature change and a more pleasant feel to the sound. Another user has the RCA attenuators ordered who has similar electronics to mine. I shall wait and see what his experience is.
Anyway since then I have left the RCA attenuators in there as I find the sound more pleasing to my ears. I may do some more non-blind A/B testing when I get the fancy to.

Anyway short summary with RCA attenuators: overall music reproduction feels improved and more pleasing. Better depth. Dynamics feel more natural with a slight sacrifice on treble "snap" and microdetail. Movies are not as pleasing. I feel (without proper proof) that it may be a possibility that the xda-1 is outputting a voltage that may be overloading the UPA-2 (as well as my headphone amplifier).

Edit: Another possibility I have entertained is that this may simply be the limitation of class A/B amps as they get past pure class A mode limits. My speakes are reasonably efficient and the slightly harsh compressed sound comes on mainly when there are dynamics which aren't necessarily tremendously loud but loud in comparison.

[garbulky]

Playing around with speaker positioning...tried pulling my speakers foward farther away from the walls as I could. I wish I had a bigger room to try this,

[garbulky]

After pulling my speakers out, there was less flattening of the sound. I wouldn't call it incredible depth but there was a small perceptible difference. Unfortunately, due to room dimensions and having to move my listening couch back nearer to the wall, room effects are presenting a coloration to the audio. Someday, Im going to have to spring for room treatments.

Anyway, the purpose of this post: I was listening to "The Reiner Sound" which is a conductor with the chicago symphony. On the XDA-1, this really sounds very good. The dynamics can eally get out there. On track 6, Litz totenatz, after a very loud orchestral peice, the piano plays soft melodies with a lot of soft dynamics. The Xda-1 captured all of this with good detail, nuance and was able to present depth information on the piano key and got close to capturing the size of the instrument. It really was quite a spectacle and that was the quietest bit of the track!
t's a very clear DAC. It's main shortcoming is listening to it at soft volumes. But pump up that volume and it becomes very nice. If the XDA-2 can manage this clarity with its analog control AND better it at low volume performance, it would be a good deal even without the headphone amp and improved jitter reduction and high res USB.

I enjoyed it so much that I have to say that UPA-2 was one of the best buys I've made just at its abilituy to keep up with the xda-1 and cost $300. What a no-brainer at that price. Such neutrality, clarity and power. When the xpa-200 gets offered again, I hope it sells well enough to keep this model in business because it really needs to be kept out there especially with its (assumed) lower gain circuitry.

[RichGuy]

I have an Xonar Essence ST in my HTPC music server that I built. The Essence ST is a very nice audio card but I also prefer sending my HTPC's audio to another DAC, I use my PR-SC885 processors Burr Brown DAC and I am very pleased with the way it sounds.

I have noticed that the Xonar Essence ST's digital coax output sounds amazing and is the best sounding digital output I have used with my HTPC. It has a cleaner and more detailed sound than the Auzen X-Plosion 7.1 cards digital coax output which it replaced and that was also a very good sounding card.

So even using an external DAC the Xonar Essence ST is a great choice to get the best sound quality.

[garbulky]

That's good to hear. I'll have to try that when I get a chance.

[briank]

Sept 5, 2012 20:50:27 GMT -5 garbulky said:

Update 9/2012

Edit: Another possibility I have entertained is that this may simply be the limitation of class A/B amps as they get past pure class A mode limits. My speakes are reasonably efficient and the slightly harsh compressed sound comes on mainly when there are dynamics which aren't necessarily tremendously loud but loud in comparison.

I can assure you it's not a limitation with Class A/B amps. My class a/b Lexicon remains smooth and effortless even at very high volumes with no harshness or edginess.