[HeadphoneAddict]

That's too bad for you guys dealing with hiss.  My HDP and uDAC/uDAC-2 are quiet with my Westone ES3X which are brutal with revealing hiss and noise in my EF5, SAC KH1000, an SRG II, and even my ALO Amphora.  
 
My Amphora has easy to hear hiss with ES3X and W3, and I just can't hear it with my Nuforce amps with those same earphones (I have not tried the ES3X on the original Icon Desktop amp which my son uses to drive his Stax now).  It seems there are a good number of us who don't hear hiss, and a good number who do.  I don't know how to explain it, other than some with high hearing sensitivity, or possibly the source being used, or manufacturing variance?

 

[Sid-Fi]

I wish I could audition several other units to see how closely they compare to mine. I've always been able to discern hiss pretty easily and have a hard time buying that others would hear any on my unit since it seems absolutely absent of it. I would think source/headphone or variance would be more likely. Sure would be nice to find out...

 

[bcwang]

Quote:

I wish I could audition several other units to see how closely they compare to mine. I've always been able to discern hiss pretty easily and have a hard time buying that others would hear any on my unit since it seems absolutely absent of it. I would think source/headphone or variance would be more likely. Sure would be nice to find out...

It's unlikely manufacturing variation as I have heard a couple of units each of different models of nuforce products and the hiss level is consistent.  
 
It's not source dependent, because all any of them require is power for me to hear the hiss.
 
It is headphone sensitivity and a person's hearing sensitivity combination dependent.  It's as simple as that.  
 
My friend can hear a sony tv is on from the whine it produces from 50 feet away in a separate hallway from the room it's in.  I can't hear it when I'm standing right next to the tv.  People's hearing sensitivity and range differ greatly.  I wouldn't be surprised if someone heard hiss from the Tomahawk which to me is completely silent at realistic volume knob settings.

 

[kostalex]

Well, hiss and bad pot are real problems with some units, though Nuforce is trying to represent them as non-existent. Nevertheless, HDP is a great DAC and decent amp for money, one of the best bargains today. Its shortcomings do not ward me off its usage.
 
I wish Nuforce will release HDP-2 with gain switch (to avoid hiss) and nice pot.
 
A bit off-topic: I did not believed all the ravings around Nuforce uDAC until I tried it myself and its sound astonished me. It has analog-like presentation, vocals are excellent on uDAC! I could not imagine this quality is available at $100 budget. Yes, this tiny thing struggles with demanding cans like HD650, but I did not really expected it would drive them well. With easier-to-drive headphones, uDAC is nothing but a godsend. Especially I liked it with ER-4P, uDAC brings bass, warmth and smoothness to them. Also it was great with my deep modded PortaPro (see avatar), raising their speed and clarity to shocking level.

 

[cravenz]

Quote:

Well, hiss and bad pot are real problems with some units, though Nuforce is trying to represent them as non-existent. Nevertheless, HDP is a great DAC and decent amp for money, one of the best bargains today. Its shortcomings do not ward me off its usage.
 
I wish Nuforce will release HDP-2 with gain switch (to avoid hiss) and nice pot.

Agreed. But I guess I will have to look for an impedance adapter and take it from there. I'm usually fairly deaf involving calling out to people and stuff, but I guess I may be sensitive to the hiss. O well.

 

[Sid-Fi]

Anyone know when the linear power supply is coming out? I thought I remembered it was scheduled for September, but couldn't find it on Nuforce's website.

 

[jcbrunelli]

Does the HDP drive the AKG K702 with competence?

 

[cravenz]

Quote:

Does the HDP drive the AKG K702 with competence?

 
second time I am pasting this, but here is my 2 cents.
 
"just my 2 cents regarding the HDP: I have owned the HDP for a short few days and will be getting a replacement and am awaiting that. But I'd just like to put it out there that the HDP wouldn't be the best pairing with the 701s. It sounds fine obviously, but I have the M-Stage and that works better with the 702s that I have. The 701/2 sounds a little shrill on the HDP IMHO. I preferred my D10 out to M-Stage over the HDP on its own."
 
To further qualify that, I am still waiting on the replacement to arrive and I am hoping ever so much that I get a unit that suits me, but anyhow, the DAC capabilities can be heard through the 702, but I still found the shrillness to be a factor. It lacked some body and I thought this is where the M-Stage bettered the HDP in regards to the 702/1.

 

[jcbrunelli]

Thanks.

 

[comfortablyhigh]

I primarily listen to a lot of metal, and I am keen on buying grado 325is. How will the NuForce uDAC suit me? I was also looking up the Total bithead. Any recommendations?
Thanks!

 

[grokit]

The uDac and the Grados are both on the forward-sounding side, so they might not be the best match for each other. I wasn't very impressed with my loaner Bithead when I had it, but its unremarkability might be a good clean match with the 325is. You might want to consider an iBasso D4 instead of the Bithead, it has a similar form factor and superior SQ but no rechargeable battery. If your budget is low the Fiio E7 may be a good option. Then again I think the Headstage Arrow HE is starting to ship again, has good bass boost, and is offered with the DAC Stick as a combo deal.

 

[Sid-Fi]

I think the HDP definitely drives the K701/702 with competence and actually has pretty good synergy with it. I just attended a local meet this last weekend and took my HDP and evaluated it with AKG 701 for a good while as well as many other headphones including Denons, Audio Technica's, Jerry Harvey universals, etc.
 
I felt that the HDP did a nice job of bringing out the bass and getting a fuller and more engaging sound out of K701, which can sound a little lifeless and bass anemic with many amps. The owner of the K701s thought that the HDP did better than many amps he has tried with it and drove them comparably well to his Ming-Da tube amp (which even required tube rolling several times to get there).
 
Overall, I confirmed (to myself at least) that the HDP has very strong synergy with the Sennheiser HD600 and HD650, pretty good synergy with K701, and just good synergy with Denon D2000, D5000, and LA 7000 - all of which I all tried over the weekend. It also did very well with JH 13 universals, Westone UM3X, and IE8 - not having any hiss with any of them according to several members present. On the other hand, I didn't think it had much synergy with a few Audio Technica cans I tried, but then again I don't really like AT's that much so that might just be my bias. 
 
Also, not to get into the volume pot issues again, but I thought it was ironic that a local friend that attended the meet and has a 2-3k tube amp and balanced HD 800s liked the HDP and specifically remarked (unsolicited) that is has a really nice and smooth volume control...
Quote:

Does the HDP drive the AKG K702 with competence?

 

[hktam]

Does the HDP drive the AKG K601 well?

 

[miyinan]

What other amps were your comparing to? From what I read, K701 doesn't go well with tube amps.
 
Quote:

I think the HDP definitely drives the K701/702 with competence and actually has pretty good synergy with it. I just attended a local meet this last weekend and took my HDP and evaluated it with AKG 701 for a good while as well as many other headphones including Denons, Audio Technica's, Jerry Harvey universals, etc.
 
I felt that the HDP did a nice job of bringing out the bass and getting a fuller and more engaging sound out of K701, which can sound a little lifeless and bass anemic with many amps. The owner of the K701s thought that the HDP did better than many amps he has tried with it and drove them comparably well to his Ming-Da tube amp (which even required tube rolling several times to get there).
 
Overall, I confirmed (to myself at least) that the HDP has very strong synergy with the Sennheiser HD600 and HD650, pretty good synergy with K701, and just good synergy with Denon D2000, D5000, and LA 7000 - all of which I all tried over the weekend. It also did very well with JH 13 universals, Westone UM3X, and IE8 - not having any hiss with any of them according to several members present. On the other hand, I didn't think it had much synergy with a few Audio Technica cans I tried, but then again I don't really like AT's that much so that might just be my bias. 
 
Also, not to get into the volume pot issues again, but I thought it was ironic that a local friend that attended the meet and has a 2-3k tube amp and balanced HD 800s liked the HDP and specifically remarked (unsolicited) that is has a really nice and smooth volume control...

 

[jcbrunelli]

I think that it is true only for cheap OTL amps.
 
Quote:

What other amps were your comparing to? From what I read, K701 doesn't go well with tube amps.