Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › HE-500, LCD2, D5000, DT770, SR80, on a speaker amp (Emotiva mini-X A-100) Project
New Posts  All Forums:Forum Nav:

HE-500, LCD2, D5000, DT770, SR80, on a speaker amp (Emotiva mini-X A-100) Project - Page 243

post #3631 of 3642
Quote:
Originally Posted by davidsh View Post


If NAD is true to their specs and your hearing isn't overly sensitive and your room isn't extremely quiet.. Then it's gonna be good. The emotiva has worse noise figures, and significantly so, supposing the specs for the mini-x is a-weighted, which they most likely are.


Thanks again, you have been extremely helpful. I'll post how it all works out. Now I need to find somebody to build my cables as I have no equipment or time. The way I see it, I might spend say $200 on a decent 10 foot balanced cable (or so I hope). If I like the sound as much as I think is possible I might actually be able to sell my dedicated headamp. Although I love the a18 I have, if I already have a very competent integrated on hand it begs the question why have the additional component? I will be able to do some testing to see which provides the better listening experience. I love the idea of using my NAD more and having access to a remote control from my couch. Cheers.

post #3632 of 3642
You're welcome. Don't hesitate to ask if you got any other questions.
post #3633 of 3642
Quote:
Originally Posted by davidsh View Post

You're welcome. Don't hesitate to ask if you got any other questions.


You may regret that offer! But thanks, I will take you up on it.

post #3634 of 3642
The Q701 is pretty revealing and not all that insensitive. I doubt you'd ever hear any noise with the he560.
post #3635 of 3642
Quote:
Originally Posted by jasonb View Post

The Q701 is pretty revealing and not all that insensitive. I doubt you'd ever hear any noise with the he560.


Sweet, sounds very promising. I am trying to think why if you have a very good integrated amplifier that using speaker taps that that route wouldn't provide superior or at least equal performance as compared with a good headamp. I am unrealistic in thinking that speaker taps from my M3 should sound as good as my Yulong A18 does?

post #3636 of 3642
It could very well be just as good if not better. Generally you can get more for your money in speaker land as well, the market for speaker amps is much bigger than the market for headphone amps, which is just a niche after all. That is what I hear. Noise, imbalance and volume control are the biggest problem with the speaker amps.
post #3637 of 3642
Well, I was about ready to buy a Schiit Vali or Magni. I'm sure my Emotiva from the speaker taps sounds better than those.
post #3638 of 3642
Quote:
Originally Posted by davidsh View Post

It could very well be just as good if not better. Generally you can get more for your money in speaker land as well, the market for speaker amps is much bigger than the market for headphone amps, which is just a niche after all. That is what I hear. Noise, imbalance and volume control are the biggest problem with the speaker amps.


Very true. I am hoping that my M3 doesn't suffer from these problems as much. I know it isn't summit-fi by any stretch, but I think the M3 is a very well made and designed integrated so I will remain hopeful. Any suggestions on a good place to have custom cables made? Thanks.

post #3639 of 3642

There seems to be one very important aspect of the amplifier that hasn't been mentioned much here....

 

There are three reasons why using a "speaker amplifier" may sound better with particular headphones than using a "headphone amplifier":

 

1) If you have something like HiFiMan 6's, then their efficiency is very low and you simply need the power to drive them properly. If that's the case, then you probably don't need to especially worry about noise floor, and you'll have plenty of range on the volume control, so you won't be wanting any sort of attenuators.

 

2) Maybe it's simply a matter of the specific amplifier just plain sounding better....

 

3) Maybe it sounds better because your headphones really prefer having a low source impedance. Most (but not all) headphone amps have a somewhat high output impedance, which tends to result in a not especially flat frequency response, and one that varies depending on what headphones you use. Like speakers, most headphones present a rather complex load impedance to the amplifier - this complex impedance reacts with the output impedance of the amplifier to produce what can be very wide variations in frequency response. Some headphones are also sensitive to the amount of damping they get from the amp. (Just like speakers, damping allows the amp to "control" the movement of the diaphragm, and so possibly reduce distortion and other nonliniearities like ringing.)  The result is that a given pair of headphones will sound quite similar on any amplifier with a low output impedance, but may sound very different on different amplifiers if their output impedances are high enough to interact with the impedance of the cans.   

 

If you want to avoid confusion and poor results, it's important that you figure out which of these applies to you....

 

Here's why:

 

Most "normal speaker amplifiers", including the Mini-X, basically have a fixed-gain stage that is fed by the volume control - which is a variable attenuator. Since speaker amplifiers are designed to be used with speakers, they tend to have a much higher noise floor than, say, a headphone amp designed to work with sensitive IEMs.

 

If 1) applies to you, then your headphones pretty much act like speakers; they need the power, and aren't so sensitive that the noise floor is an issue, so its all good :)

 

If 2) applies to you, then you may or may not have issues because of the noise floor of the amp and because, with normal sensitivity phones, it plays so loudly that you barely get to move the Volume knob off the end stop.

 

If 2) or 3) applies to you, then you may be hearing the noise floor, and you may have trouble because the volume control doesn't "go down far enough"..... and, if so, then here's "the deal"...

 

If you put attenuators on the INPUT of the amp (the Mini-X), then you will be attenuating the input signal level. This will reduce the output level for a given input level, and so let you run the amp with the volume control turned up a bit more - which will make it easier to control. It will also attenuate any noise that happens to be coming from your source. And it WON'T RAISE THE OUTPUT IMPEDANCE OF THE AMP AT ALL. However, it also won't do anything about the noise floor at the output.

 

If, instead, you put an attenuator on the OUTPUT of the amp, then you will be attenuating the output level; however, you will also be RAISING the output impedance. The result is that you'll be able to use the volume control set further up, and you WILL reduce the output noise floor, but you will be sacrificing the super-low output impedance.

 

I'll toss you a few representative numbers here....

 

The output impedance of a "typical headphone amplifier" can range from about 0.1 ohms or less to as much as 100 ohms or so.
(The output impedance of the headphone outputs on our DC-1 DAC  is well below 1 ohm; many small headphone amps are around 10 ohms; most receiver outputs tend towards that high number).

The output impedance of a Mini-X is on the order of 0.02 ohms or so (the actual number depends on how you reference it - but it's REALLY low).

 

The output impedance of a Mini-X with an attenuator on its OUTPUT, as seen by the headphones, will depend entirely on the values you choose for the attenuator.

 

Specifically, if you use a "basic two resistor voltage divider" - with one resistor between the output and the load, and a second resistor to ground, then the output impedance will be the parallel combination of the two resistor values you use - in series with the output value of the amp itself. Either way, by doing so you will be raising the source impedance, and so reducing the damping and increasing the interactions between the amp and the headphones.

 

For example , if you use a divider composed of a 100 ohm resistor in series, and a 10 ohm resistor to ground, you will raise the output impedance of the amp (as "seen" by your cans) from about 0.02 ohms to about 9 ohms. This is a significant difference, and quite possibly a high enough output impedance to result in audible interaction with your headphones - both in terms of non-flat frequency response and reduced damping. If, instead, you use a 22 ohm resistor in series, and a 2 ohm resistor to ground, then your overall output impedance will be about 1.8 ohms.

 

You'll get the same 10:1 voltage reduction with either one, but that 22 ohm resistor will have to handle significantly more wattage. However, if your headphones are medium impedance (say 32 ohms or 50 ohms), the lower values will give you a lower source impedance, which may well give you an audibly better frequency response due to reduced interactions with the phones, and may also give you cleaner sound due to the better damping. (Of course, if noise isn't a problem, it's best of all to connect the phones directly to the amp's outputs.)

post #3640 of 3642

I just bought a used pair of HE-500's a few months ago, and think a mini-x would be a great starter amp for them. I've been reading this thread and others for probably the past 10 hours. Every time I think I know what I will need to do I find something else that makes me further confused. If I get the Stereo>Dual Mono>Banana adapters do I still need to add in resistors, and is there another adapter for that? What is the downside of this solution aside from clutter?

post #3641 of 3642

Generally resistors are not needed if you a hooking up to a solid state amp like the mini-x. You may add resistors to either control the volume attenuation (increase volume play) or to reduce the noise floor. Resistors also help the amp see a proper impedance (e.g. 8ohms).

 

For hooking up to the amp I strongly suggest getting a 4-pin XLR cable with a banana plugs adapter. The mini-x has a shared ground output but not all amps do. If ever you migrate from the mini-x to another amp that is balanced and does not share a common ground the XLR cable would still work either way and provide protection in both instances.

post #3642 of 3642
Quote:
Originally Posted by wessabi View Post
 

I just bought a used pair of HE-500's a few months ago, and think a mini-x would be a great starter amp for them. I've been reading this thread and others for probably the past 10 hours. Every time I think I know what I will need to do I find something else that makes me further confused. If I get the Stereo>Dual Mono>Banana adapters do I still need to add in resistors, and is there another adapter for that? What is the downside of this solution aside from clutter?

IMO just doing what I did was the cleanest solution: LINK

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphones (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphones (full-size) › HE-500, LCD2, D5000, DT770, SR80, on a speaker amp (Emotiva mini-X A-100) Project