[Armaegis]

Ah, my mistake. In any event, double amping is not the huge evil that some make it out to be, so don't worry about it.

 

[Ceej]

Well it turns out it may be... I got the amp today, plugged it in RCA to 3.5mm to 6.5mm, and everything mute I can hear A LOT of noise. I was plugged into my main amped-port on my Xense, which is an EMI-shielded card, then plugged it into my onboard. No difference. I am surprised, I can hear the noise over the sound and the sound is distorted at points as well. It goes to zero at about 33% on the amp's knob, but music at this volume isn't quite loud enough and mild distortion is present. It almost is like parts kind of fade in and out. Which is a shame... because what I DO hear I can actually feel the sound and the mids are a LOT better. I am at least convinced that the other setup wasn't working for me. No noise when the amp is plugged RCA --> same cable into iPhone
 
Not sure WHAT part is the problem. I get the same noise into myonboard WITHOUT the adapter... I'm guessing the conclusion is I Need a DAC?x
 
If I get a DAC will it change the sound appreciably? Do DACs and amps have to synergize well or is the AMP/headphone combo more important? Any suggestions in the $100-$200 range?

 

[Armaegis]

Geez at first it sounded like there was something wrong with the amp... but it works just fine from your iphone???
 
But you get the distortion from the Xense and from the built-in computer jack? I'm not sure what that could possibly be, and I feel like a new dac would not be the solution.
 
Maybe try it on a laptop, or on a friend's computer first. Something doesn't add up here.

 

[Ceej]

I'll pull out my old laptop later but its perfect no noise coming through my surface tablet. I also get the same noise through my pc front outputs. I am surprised though... The xense has an emi shield which is 0% effective... No difference compared to onboard.

 

[Armaegis]

This kind of noise/distortion isn't coming from EMI. I can't even chalk it up to a ground loop. There is something very very odd happening here, and I have no idea what that is. Sorry I can't be more help

 

[Krutsch]

I'm glad this thread came back to life... I was thinking about the HA-200, but then NuForce changed owners, et al., so I took a long excursion into tube-land.
 
Anyway, I am back to looking at the HA-200, based on the positive review commentary and the new, lower price (seems to be $299 on Amazon).
 
Most of the comments here are related to driving more difficult 'phones (e.g. HD-650, HE-6). For my HD-650s, I don't see needing to replace my Woo OTL.
 
I am curious how the HA-200 performs with lower impedance cans, like my Grado RS2i and AQ NightHawks, if anyone cares to comment.
 
Thanks, in advance.

 

[Armaegis]

It really has more to do with the individual impedance curve of the headphone. The Nighthawk has a flat curve, and even Grados are relatively flat compared to the likes of Sennheiser. So overall it'll be fine.

 

[Krutsch]

^^ That's helpful, thanks.

 

[vadergr]

Hello all
 
The optoma HA200 is exactly the same model with the nuforce one.
I entered the ul website and i am not sure i see the same amplification specs ...
 
http://www.optoma.co.uk/soundproduct/HA200
 

Specification

General

Peak power output

600mW @ 16 Ohm 937mW @ 32 Ohm 530mW @ 100 Ohm 180mW @ 300 Ohm 96.3mW @ 600 Ohm"
Input impedance

22k Ohm
Output impedance

5 Ohm
Frequency response

10Hz - 20KHz
Signal to noise ratio

>106dB
Total harmonic distortion

0.0005%
Power supply

　115V/230V

Output voltage

393mW @ 16 Ohm 747mW @ 32 Ohm 383mW @ 100 Ohm 129mW @ 300 Ohm 70mW @ 600 Ohm
Volume control

Rotory
Nominal input level

0.5V
Recommended headphone impedance

32 to 600 Ohm
Balanced mode

200 Ohm, 14.6Vrms
Connections input

RCA L+R, single XLR
Connections output

6.3mm Stereo jack, single XLR

 

[zilch0md]

Interesting - it certainly looks like the original Nuforce HA200.  Perhaps the specs are just more "honest."

 

[manbear]

I'm glad this thread came back to life... I was thinking about the HA-200, but then NuForce changed owners, et al., so I took a long excursion into tube-land.

Anyway, I am back to looking at the HA-200, based on the positive review commentary and the new, lower price (seems to be $299 on Amazon).

Most of the comments here are related to driving more difficult 'phones (e.g. HD-650, HE-6). For my HD-650s, I don't see needing to replace my Woo OTL.

I am curious how the HA-200 performs with lower impedance cans, like my Grado RS2i and AQ NightHawks, if anyone cares to comment.

Thanks, in advance.

I use the Nuforce with my Fostex TH600. Works great, though there is a tiny bit of noise I cant hear with the harder to drive HE-400i. Though it drives the 400i perfectly well. The only headphone I have that the nuforce cant power is the AKG k340.

 

[Armaegis]

  Interesting - it certainly looks like the original Nuforce HA200.  Perhaps the specs are just more "honest."

 
I seem to recall the old specs not really making much sense in the first place. Like someone grabbed some datasheet stuff and simply used ohm's law to calculate outputs. I think I ran some of my own measurements in my review.

 

[lvandrewazar]

Any new updates on running these things balanced? I've got one, and am looking at getting a second, but it needs to be worth if for how convoluted the setup would be.

 

[Velomane]

Not sure what your

  Any new updates on running these things balanced? I've got one, and am looking at getting a second, but it needs to be worth if for how convoluted the setup would be.

Not sure what you're after. I run these balanced to drive my HE-5LE. Ample power to drive them and very quiet.

 

[lvandrewazar]

Any quirks with the setup really. Also, what's a nice DAC to go with them? I was looking at the Emotiva XDA-2 2nd gen.