Upgrade for Asus Xonar Essence STU

[Giupy]

Hey guys!

Sooo the title is pretty much self-explanatory, I would like to upgrade part of my current setup, respectively my Asus Xonar Essence STU and I kind of need help with that.

I've looked around the web for some equipment, but it generally comes down to either being quite a bit out of my price range or devices which I don't really know too much about.
So I turn to you, Head-Fi! Home to the best and the brightest.

Some general guidelines which I thought up are:

Budget - ~500$
Build - Would prefer a DAC&AMP combo, having both of them built into a single device, but that's not a must have
Connectivity - Would prefer an optical in

Additional notes:
I don't really care for portability, because I'm going to be using it at home, on my PC.
Will use it to drive my Hifiman HE-400 and in the near future a pair of Philips Fidelio X2.

I also welcome the alternative of using another device to complement my current setup.

As always, thank you for your help

 

[billybob_jcv]

Why are you upgrading? What are your goals? (other than spending money!)

 

[Giupy]

Why are you upgrading? What are your goals? (other than spending money!)

Sound quality, hopefully... I'm not entirely happy with it. I've heard similar headphones driven via tube amps and the sound was considerably better. I was honestly looking at the Schiit Valhalla II, but I would like to know more before actually doing an upgrade... That's pretty much why I posted here.

And no, my goal is not to spend money. It's actually to spend as little as possible. I got the STU for a very small price in mint condition (130$), I can easily resell for a higher price, so I can't exactly say that I'm losing anything in terms of selling my STU, except the device itself (but it wouldn't exactly count as a loss if I'm selling it).

 

[billybob_jcv]

Hmm - I just looked at the specs on the STU. It shows an output impedance for the headphone jack of 10 Ohms. I think that's a problem for the Philips X1 - it's only 30 Ohms. I think there's some risk of hiss and distortion with that combination.

The STU specs also don't show the power output to the headphone port - it just says 7 Vrms, and, if I'm remembering my electronics class from a million years ago, I think that's not a useful spec without knowing the impedance load where that 7 Vrms measured. If I'm wrong, I'm sure someone will smack me and provide the correct answer.

What I'm thinking is that although fairly low impedance, the HE400i are not very efficient (93 dB IIRC). It's possible the STU just can't provide what the HE400i really need.

I would think the Vahalla2 would do the job. What you could do is keep the STU to just use as a DAC and give the Schiit amp a try.

 

[PurpleAngel]

I would think the Vahalla2 would do the job. What you could do is keep the STU to just use as a DAC and give the Schiit amp a try.

 
+1,
Giupy, get a tube amplifier and connect it to the unbalanced RCA outputs on the back of the STU.

 

[Giupy]

 
Quote:

I would think the Vahalla2 would do the job. What you could do is keep the STU to just use as a DAC and give the Schiit amp a try.

Quote:

   
+1,
Giupy, get a tube amplifier and connect it to the unbalanced RCA outputs on the back of the STU.

 
 
Very well, will try that as soon as I can. Thanks guys!

 

[Giupy]

Hmm, I've actually given that some thought and would actually like to sell the STU.

What's a good and cheap DAC that would go well with the Valhalla II?

 

[PurpleAngel]

  Hmm, I've actually given that some thought and would actually like to sell the STU.

What's a good and cheap DAC that would go well with the Valhalla II?

 
Schiit Modi

 

[Giupy]

So... A while after making the initial post I had been contempt with just waiting to get a Valhalla II and a Modi, but then I saw the Nuforce Icon HDP. Pre-amp, Amp and DAC all in one. Quite the attractive package and it has a good price tag on it.

However, would the sound quality be better than it was for the Asus Xonar Essence STU?

I know the STU has as follows:
Audio Processor :C-Media CM6631A High-Definition Sound Processor
Headphone Amplifier: TPA6120A2
Op-Amps: Texas Instruments NS-LME49720 and NS-LM4562NA

However, I do not know much about what makes the Nuforce Icon HDP tick. Even if I did, I wouldn't know much about the respective parts or their performance, so I'm back to pestering you guys!

Would it be a good upgrade? I believe it would be roughly 250GBP with delivery included.

Also, alternative propositions are always welcome.

Additional note: I would still love the Valhalla / Modi combo, however it costs an extra 240$ in shipping and import taxes, due to living in Romania (I hate you VAT).

Thanks!