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[LIST][OPINION] Amp recommendations for Fostex/Denon Headphones. - Page 15

Poll Results: What do you think of amp recommendations in general?

 
  • 11% (17)
    Disgustingly not thought out, just recommended from the single amp they have tried
  • 13% (19)
    Poorly thought out, mostly blind brand loyalty
  • 42% (61)
    50/50, a lot of zealots but about the same number of helpful recommendations
  • 11% (16)
    Mostly people here know what they are saying
  • 14% (21)
    WiR3D is a zealot.
  • 6% (9)
    I disagree with you most things, people can recommend from there own experience, even if it is just the one amp that they own.
143 Total Votes  
post #211 of 436
Thread Starter 
Quote:
Originally Posted by chewy45 View Post

I just replaced my E7 with an ODAC by JDS labs so now I have the ODAC paired with the Schiit Asgard amp and Denon AH-D5000's. I can't believe the how much better the D5000's sound with this set up!

Good to hear :) and glad your enjoying it.

Quote:
Originally Posted by cocolinho View Post

thanks.

Aune T1 looks very attractive...

It does, and I would love one for my AKGs, or some Grados or even some Senns if it has the power. But I HIGHLY doubt it will suit the Denons.

post #212 of 436
So I will stick to :
DAC :Odac or HRT ms2
AMP : O2 or Matrix M stage

Target is now to combine one dac and one AMP for the lowest price biggrin.gif
post #213 of 436
Thread Starter 
Quote:
Originally Posted by cocolinho View Post

So I will stick to :
DAC :Odac or HRT ms2
AMP : O2 or Matrix M stage
Target is now to combine one dac and one AMP for the lowest price biggrin.gif

out of that. ODAC + M-stage, with a powered hub for the ODAC.

post #214 of 436
Quote:
Originally Posted by WiR3D View Post

Ok but the DAC is what I'm worried about, 

I've been reading arround quite a bit. I'm starting to get more and more interested in getting a desktop setup. I've been reading arround quite a bit and I'm leaning further and further towards spending my christmas money on the Yulong D100. What do you think of that? is it a solid purchase at arround 480$ in your opinion? How much of an upgrade would it be compared to the E17? Another question I have is, how does the source come into play when you have a dac and an amp (or combo) e.g from an usb port on my motherboard (pc) or from my mobile phone or laptop? I appriciate your support so far!

post #215 of 436
Thread Starter 
Quote:
Originally Posted by Man7rah View Post

I've been reading arround quite a bit. I'm starting to get more and more interested in getting a desktop setup. I've been reading arround quite a bit and I'm leaning further and further towards spending my christmas money on the Yulong D100. What do you think of that? is it a solid purchase at arround 480$ in your opinion? How much of an upgrade would it be compared to the E17? Another question I have is, how does the source come into play when you have a dac and an amp (or combo) e.g from an usb port on my motherboard (pc) or from my mobile phone or laptop? I appriciate your support so far!

The Yulong D100 and the Denons have synergy, and its not just a DAC with a slapped on amp or visa versa. I really think its a good investment. 

 

Compared to the E17, you won't be getting 4x the sound quality, the law of diminishing returns after all. But let me put it this way, you wouldn't need to upgrade until your going reference grade. Which is 4x the price of the Yulong for a DAC and amp separate.

 

So it depends. Personally, I would go for the E17, until I feel I need more, then Yulong D100 - I have always enjoyed incremental upgrades. And its actually more fun then jumping to reference grade, from what I read. But if you just want to get it over and done with - then D100 straight. The DAC section is good enough to keep up with much more expensive DACs too. 

 

With the D18 I know source is extremely important, with the D100 ... erm... good question actually. I imagine some jitter control is in place. But the HiFace 2 always exists as an option. 


Edited by WiR3D - 11/22/12 at 3:33pm
post #216 of 436

I've been thinking of the new Yulong too...with my Denon D5000's.  Anybody have anything to report on running the Yulong D100 MKII with a Denon D5000 or D7000 or D2000 for that matter?  I keep hearing that its supposed to be a good match with the Denons but havent read anything directly from a Denon owner.

post #217 of 436

I have the opportunity to buy locally a Yulong D100 MKI for 270€ shipped

Should I go for this or HRT/ODAC + Matrix M stage for the same price (2nd hand too)

 

Which combo to choose?? knowing that I might add Hifiman HE400 next to my D2000 & Grado

THanks wink.gif

post #218 of 436
Quote:
Originally Posted by cocolinho View Post

I have the opportunity to buy locally a Yulong D100 MKI for 270€ shipped

Lucky! 

post #219 of 436
Quote:
Originally Posted by WiR3D View Post

The Yulong D100 and the Denons have synergy, and its not just a DAC with a slapped on amp or visa versa. I really think its a good investment. 

 

Compared to the E17, you won't be getting 4x the sound quality, the law of diminishing returns after all. But let me put it this way, you wouldn't need to upgrade until your going reference grade. Which is 4x the price of the Yulong for a DAC and amp separate.

 

So it depends. Personally, I would go for the E17, until I feel I need more, then Yulong D100 - I have always enjoyed incremental upgrades. And its actually more fun then jumping to reference grade, from what I read. But if you just want to get it over and done with - then D100 straight. The DAC section is good enough to keep up with much more expensive DACs too. 

 

With the D18 I know source is extremely important, with the D100 ... erm... good question actually. I imagine some jitter control is in place. But the HiFace 2 always exists as an option. 

I think I'll wait it out for a bit longer actually, this is kind of off topic but I ordered a pair of Heir audio 4.A CIEM's today on the black friday sale! So my wallet is sore and in need of recovery for a little while. Got mine with a bamboo faceplate and black shells if you're wondering ^^


Edited by Man7rah - 11/25/12 at 11:11am
post #220 of 436
Quote:
Originally Posted by cocolinho View Post

I have the opportunity to buy locally a Yulong D100 MKI for 270€ shipped
Should I go for this or HRT/ODAC + Matrix M stage for the same price (2nd hand too)

Which combo to choose?? knowing that I might add Hifiman HE400 next to my D2000 & Grado
THanks wink.gif

What is the difference between the D100 MKI vs MKII? If you don't mind me asking.
Cheers
post #221 of 436
Quote:
Originally Posted by willmax View Post

What is the difference between the D100 MKI vs MKII? If you don't mind me asking.
Cheers

http://www.head-fi.org/t/608098/review-yulong-d100-mkii-dac-an-update-to-an-already-excellent-device

 

I suggest you have a good 'ol read.

post #222 of 436
Thread Starter 
Quote:
Originally Posted by cocolinho View Post

I have the opportunity to buy locally a Yulong D100 MKI for 270€ shipped

Should I go for this or HRT/ODAC + Matrix M stage for the same price (2nd hand too)

 

Which combo to choose?? knowing that I might add Hifiman HE400 next to my D2000 & Grado

THanks wink.gif

Yulong, can always use it as a source for a tube later.

But damn that is a tough one.

Quote:
Originally Posted by Man7rah View Post

I think I'll wait it out for a bit longer actually, this is kind of off topic but I ordered a pair of Heir audio 4.A CIEM's today on the black friday sale! So I'll my wallet will be sore and in need of recovery for a little while. Got mine with a bamboo faceplate and black shells if you're wondering ^^

I don't blame you, I almost did.

post #223 of 436
Thread Starter 
Quote:
Originally Posted by songmic View Post
Warning: Spoiler! (Click to show)

I understand your concern regarding the use of tube amps, especially OTL tube amps with the Denons, but I beg to differ. I own a Fostex TH900, but it is nearly identical to the D7000 in terms of specs (impedance, sensitivity, design, sound signature, etc.). So let's take the D7000 for example.

 

I believe your rationale is that the D7000 is a low impedance headphone, so one would need an amp with low output impedance (which most solid-state amps are but tube amps aren't) to ensure enough damping factor to control the drivers and reduce distortion. I completely get that. However, there's something special about the D7000 (and the TH900, for that matter). We say the D7000 has an impedance of 25 ohms, but to be precise, it is 25 ohms at 1kHz. The reason we use the term "impedance" and not "resistance" is because headphones have varying resistant value depending on the sound frequency delivered. This is what impedance means, and why we need to consider looking at the impedance curve. In the link provided below, the impedance curve is the second graph from the left.

 

http://www.innerfidelity.com/images/DenonAHD7000.pdf

 

As you can see, the impedance curve is mostly flat, and the highest at 40Hz, at around 31 ohms. So the impedance variation would be 25 to 31 ohms. Compared to the HD800 (we are told it has an impedance of 300 ohms), which fluctuates between around 300 to 600 ohms, the D7000 can be said to have a very flat impedance curve.

 

http://www.innerfidelity.com/images/SennheiserHD800.pdf

 

And it is this variation in impedance that causes impedance-related distortions. The general acceptable amount of distortion, in other words variation, is 1 dB or below, which the human ears cannot discern. The formula for calculating this variation in dB is as follows: 20 * log[(Zmin+Zamp)*Zmax/(Zmax+Zamp)*Zmin], where Zmin is minimum impedance of headphone, Zmax is maximum impedance of headphone, and Zamp is the output impedance of the amp.

 

This result of this formula should be 1 or less to ensure there is no audible distortion caused by improper matching of impedance between headphone and amp. Due to the nature of this formula, the result becomes close to zero when 1. there is a large gap between Zmin (or Zmax) and Zamp, 2. there is a little gap between Zmin and Zmax, 3. the Zamp (output impedance of amp) is close to zero. Theoretically, if the impedance curve were ideally flay, meaning Zmin=Zmax, there would be completely zero distortion no matter how high the output impedance of the amp is. In other words, if the D7000 had a constant resistance of 25 ohms throughout all frequency range, you could connect it to a 100 ohm-output impedance OTL amp and still have no distortion whatsoever.

 

Because the Zmin = 25 and Zmax = 31 in D7000's case, there is a little gap between Zmin and Zmax. In such cases, the need to have a smaller output impedance of the amp becomes less important. If we were to drive it with a tube amp whose output impedance is 5 ohms, the result of the formula would show that the maximal distortion is only about 0.3 dB. At output impedance of 10 ohms, the distortion is about 0.5-0.6 dB. At output impedance of 30 ohms (which actually happens to be the "low" output impedance of WA6SE, your favorite amp with the D7000), the distortion is still around 1 dB or less.

 

So, there you have it. Although I would still advise against OTL tube amps whose output impedance are 50 ohms or higher, the D7000 is likely to work well with a wide range of transformer-coupled tube amps whose output impedance are 30 ohms or lower. Of course, there are other, much more important factors in proper matching of amp and headphones, but what I'm saying is that one would not need to worry about using tube amps in general only because they have higher output impedance than solid-states. If the D7000 had a very fluctuating impedance curve like the HD800, I would stay away from tube amps too. But as I've proved in above paragraphs, the relatively flat impedance curve of the D7000 allows it to be driven by many transformer-coupled tube amps without impedance-related distortion issues. If the D7000 sounds bad with a particular tube amp, it should be not because of damping factor but because of something else. Same goes for solid-state amps.

 

Quote:
Originally Posted by songmic View Post

 

Warning: Spoiler! (Click to show)

 

Quote:
Originally Posted by WiR3D View Post

 

Their is one problem. Take a low impedance source and connect an output impedance increasing adapter in the chain and tell me if you notice the sound gets worse. Because I sure as hell do. The same can be said for taking a source with a modest 10ohms output impedance and connecting a faux output impedance decreasing adapter to into the chain, the sound improves. Mainly in the bass region, I suppose from dampening factor? 

 

And micro details are more evident, atleast to my ears, an in my completely unprofessional test.

 

I have a good explanation for that. First of all, I don't think what you're experiencing is a matter related to damping factor. It's more of a matter related to voltage distribution between two resistors connected in a single chain, where the two resistors are the headphone itself and the output of the amp. If the output impedance of the headphone amp increases, relatively more voltage is distributed to the headphone amp output while less voltage is distributed to the headphone. Although D7000 is a low impedance, high sensitivity headphone that depends more on current than voltage, the change in voltage can still affect its performance. The reason why you're seeing the improvement mainly in the bass region is probably because that's where the impedance of the D7000 is highest, at around 40Hz (take a look at the impedance curve and you'll see).

 

Now, I never said output impedance doesn't matter. In fact, I do think having a lower output impedance is always better than having a high output impedance if every other condition is the same. However, I did not say that an "amp" having lower output impedance is always better than an "amp" having a high output impedance. My point is that as long as the calculated distortion in dB is less than 1, you shouldn't worry whether the inherent output impedance of the amp is lower or higher than one another.

 

You see, in your experiment, you intentionally altered the output impedance of one same amp. Let's call this amp A. Of course the sound and the damping factor will be altered if you change the output impedance of amp A. However, this does NOT imply that amp B, which has an inherently lower output impedance than amp A, is always the better amp. Why? Because output impedance is not the only thing that is different with A and B. If all amps were designed the same way, the only difference being output impedance, then the obvious choice would be to choose the amp with the minimal output impedance to secure more damping factor and more voltage for the headphone. But in real life, there are countless, far more significant factors that determine the "matching" between an amp and a headphone. Factors that really do matter under the assumption that both amps provide a distortion of less than 1 dB.

 

Here's a good example: amp A has inherently higher output resistance than amp B. However, amp A also has inherently higher power and voltage output than amp B. In a non-comparison study with amp A alone, the sound will degrade if you intentionally increase its output impedance. Ditto for amp B alone. Which could lead one to believe than an amp having lower impedance is better than having higher impedance. However, when comparing A and B, it turned out that A sounded better. The reason was because A also had a inherently higher power output that made up for the relative loss of voltage distribution that goes to the headphone. See what I mean? :)

 

That is why damping factor, which is measured as headphone impedance divided by amp's output impedance, should only be used as a general rule of thumb. It is widely accepted that the damping factor should be greater than 8 (meaning the amp's output impedance should be lower than 1/8 of headphone impedance), but this is to ensure the headphones will get proper damping even when they have very fluctuating impedance curve. For relatively flat headphones like D7000, the required damping factor to ensure a distortion of less than 1dB is far less than the traditional 8, even going below 1 (the fact that WA6SE's 30 ohms output drives 25 ohms D7000 proves this point). What really matters is the equation:

 

Maximum dB variation = 20 * log [(Zmin+Zamp) * Zmax / (Zmax+Zamp) * Zmin]

(distortion caused by minimal and maximal impedance value throughout the sonic spectrum)

After having some time for it to digest, I have reread songmics posts above. And my conclusion is that he is right. However to keep people on track I'm not going to update the first post with this information for the fear that it may misdirect others.  The bottom line is, impedance isn't the end all of specs. And its not even the most important. But it does play a part. Particularly in the bass regions, and when combined with a quality highish current supply it makes all the difference. 

 

But it does explain amps like the M-stage and the WA6SE and why they work to well. And I encourage those who wan't a deeper understanding to read them thoroughly.

 

For the purposes of this thread, sticking to the rules of thumb I have provided cover all the bases, including colouration. So it need not change.

post #224 of 436

Could we quote songmic's post on the first post, in a spoiler for those who wants better understanding of the whole impedance mismatch/affecting frequency issue?

post #225 of 436
Quote:
Originally Posted by WiR3D View Post

 

After having some time for it to digest, I have reread songmics posts above. And my conclusion is that he is right. However to keep people on track I'm not going to update the first post with this information for the fear that it may misdirect others.  The bottom line is, impedance isn't the end all of specs. And its not even the most important. But it does play a part. Particularly in the bass regions, and when combined with a quality highish current supply it makes all the difference. 

 

But it does explain amps like the M-stage and the WA6SE and why they work to well. And I encourage those who wan't a deeper understanding to read them thoroughly.

 

For the purposes of this thread, sticking to the rules of thumb I have provided cover all the bases, including colouration. So it need not change.

 

I'll add one more important factor regarding impedance that I haven't mentioned before. I have stated that any output impedance of a headphone amp is tolerable as long as the distortion caused by the difference between the maximum and minimum resistances in the frequency-impedance curve is less than 1 dB, by the use of a mathematical formula.

 

However, this alone does not explain why an amp with high output impedance, such as many OTL amps, doesn't work so well with low-impedance orthodynamic headphones like Audezes or Hifimans, which have a VERY flat impedance curve. And in fact, these ortho headphones still have higher impedance than 25-ohm Denon or Fostex headphones. The distortion would be much, much lower for these headphones, yet OTL's are bad for them. Why?

 

This has something to do with the voltage distribution between headphone and amp output, and another value known as efficiency/sensitivity (which is measured as dB/mW).

 

When a headphone is connected to an output, the headphone and the output section of the amp forms a "series connection." In a series connection, the amount of voltage distributed to each part is determined by the ratio of their resistance/impedance ratio. The lower the headphone impedance, or the higher the output impedance of the amp, less voltage is distributed to the headphone. If the output impedance of an amp is very small (less than 0.1 ohm), or if the headphone has very high impedance (300-600 ohms), nearly 100% of the voltage will be distributed to the headphone. This explains high voltage swing is more important than current for high-impedance headphones like Sennheisers. Conversely, if the headphone impedance is low and the output impedance of the amp is high, less voltage will be distributed to the headphone. Imagine an OTL amp with 75-ohm output impedance driving a 25-ohm D7000. In this case, the ratio of voltage distribution of D7000 and amp output will be 1:3. Only 1/4 of the entire voltage in the circuit is distributed to the headphone.

 

Because voltage is relatively small, current plays a more important role for driving low impedance cans. (Power = Current x Voltage) The good news is, 25-ohm Denon and Fostex headphones have very high efficiency/sensitivity at 100 dB/mW, meaning it needs relatively less power to drive these cans well. On the other hand, the sensivity of orthos such as Audezes, Hifimans, is somewhere in the 80's and 90's dB/mW. Since we're dealing with dB which is in logarithm, 80 dB/mW and 90 dB/mW means that these headphones are 1/100 and 1/10 less sensitive than 100 dB/mW, or that they would need 100 and 10 more times the power to be driven properly, respectively. That's why high output impedance amps are a no-no for orthos; not because of distortion, but because of lack of power. But the Denons and Fostex have high sensitivity, so we need not worry about lacking power; we should worry more about whether the distortion is greater than 1 dB, the smallest difference in volume that the human ear can discern.

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