# Impedance Adapters/Cables | Explained & Listed



## WiR3D

I created this thread because impedances can be very confusing to non-DIYers. an impedance adapter in the general actually refers to an impedance INCREASING adapter, and is often used incorrectly. Here is a good article explaining why impedance matching is important.
  Output Impedance
   
   
*Impedance Increasing adapters*​  Generally referred to when referring to an impedance adapter, but often used incorrectly, myself included. It essentially increases the output impedance of the source or amp.
  Used to allow you to use more sensitive IEMs with your desktop amps. It lowers volume and raises the noise floor, essentially making your IEM's less sensitive.
   
*Premade:*

*Adapter/Cable*​*Price*​*R-ohm*​*Format*​ Etymotic ER4P -> ER4S adapter $50 75 Cabled Hisound Golden Impedance Cable $60 70 Cabled Ultimate Ears $50 100 Cabled APureSound Mini to Mini $45 75 Adapter APureSound Mini to Mini $45 120 Adapter APureSound Mini to 1/4" $55 75 Adapter APureSound Mini to 1/4" $55 120 Adapter
   
*Custom Resistance:*

*Company*​*Price*​*Format*​ APureSound $60 Mini to Mini Adapter APureSound $70 Mini to 1/4" Adapter Ebay: *AW Audio Accessory* $22 Mini to 1/4" Adapter Ebay: *AW Audio Accessory* $40 Mini *L* shaped Adapter Ebay: *AW Audio Accessory* $18 Mini to Mini Adapter Ebay: *WeMakeAmp Audio Workshop* $12 Mini to 1/4" Adapter Ebay: *WeMakeAmp Audio Workshop* $11 Mini to Mini Adapter
   
  I would like to update this list, so please add suggestions.
   
   
*(Faux) **Impedance Decreasing Adapters*​  What these would do is decrease the output impedance of a source or amp and allow it to pair better with certain low impedance headphones, which are affected quite a bit by bad impedance matching.
_Note:_ not impedance transformers, since they can degrade sound quality, it is not a problem in very high end Amps such as those from Woo audio.
_Note:_ The output impedance is not changed in any way, it appears lowers from the headphones perspective, and the load impedance appears higher from the amps perspective,
   
*EXAMPLE:*
  What you need is an adapter that essentially has the following configuration(for each channel,) the downside is it wastes power, but using the ASUS Xonar essence STX as an example it will lower the output impedance of the soundcard from 10 ohms to about 4 ohms. And still have a maximum SPL of above 110db.
   
  Using a 24 ohm resister instead of the 20 ohm will result in a slightly higher LOAD impedance.
   

   
   
  This is relatively simple to make just as are the impedance increasing adapters above, I have yet to find any for sale, I will be making my own for experimental purposes.
   
*How do I build one and which resistors do I use?*
   
  Quote: 





stv014 said:


> Let's say we have an adapter with a *24 Ohm serial*, and a *4.7 Ohm parallel* resistor, the *headphone impedance is 25 Ohm*, and the card has an *output impedance of 10.5 Ohm*. This means that:
> - the amplifier sees a *load* of *10.5* + *24* + 1/(1/*4.7*+1/*25*) = *38.46 Ohm* (i.e. the headphone+adapter combination is ~28 Ohm)
> - the headphone sees an *output impedance* of 1/(1/*4.7*+1/(*10.5*+*24*)) = *4.14 Ohm*
> - the *damping factor* is increased from 2.38 to 6.04
> ...


 

  
   
*Disclaimer: I take no responsibility for any damage to your amp or source, it is your duty to ensure you are using the correct components, and to double check and tripple check.*
   
_*Thanks to:*_
_stv014_
_Chris J_
_Steve Eddy_


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## WiR3D

wow no1 knows any others?


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## Byakushiki

There was this UE impedance adapter, not sure if it counts as a cable though. I believe it was rated at ~100 ohms.


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## WiR3D

I found it, thanks


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## WiR3D

Updated


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## WiR3D

updated again
   
_EDIT: Weeee post 100_


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## WiR3D

I'm contemplating stating the resistors used, it will take sum time to find out, if there is a demand for it, I will do it.


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## WiR3D

updated again


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## WiR3D

I'm amazed this isn't getting more attention, especially with the importance of impedance matching.


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## Chris J

I'm not sure this does what you think it does?
  What are you trying to do?
  A true impedance matcher is a transformer.


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## WiR3D

well originally and from popular consensus, in the posts i read, it appeared that they would raise the noise floor, lower volume, and ADD to the resistance of the headphones.
   
  However I am currently being educated by *stv014 *and it seems its not the case.
  What the adapter does, is pretty much raise the noise floor and lower and the volume, BUT it adds to the AMPs output resistance not to the total resistance of the headphone.
   
  So I'm going to update the main post soon, after i understand a bit more of the minor details.
   
  My actual goal is to either increase the resistance of my headphones which now seems impossible,
  OR decrease the output resistance of an Amp to make it pair better with low impedance cans.


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## Chris J

Broadly speaking, if you have a good, low impedance desktop amp and you are using 32 ohm Grados or 600 ohm Beyers or anything in between, then you do not need an "impedance adaptor".
   
  An impedance adaptor made up of one or two (or more) resistors will not decrease the output impedance of an amp.
  If that is what you are looking for, then, unfortunately, you need a lower output impedance amp.
   
  Some guys use resistive networks they call "impedance adaptors" to allow them to use very sensitive IEM with their desktop headphone amp.
  Reason:
  Their headphone amp has too much output (actually has too much voltage gain) for their IEM, they have a hard time controlling the volume, i.e. volume control cannot be use above 9-10 o'clock, they hear too much hiss.
   
  this may be useful to you:  
http://www.head-fi.org/a/glossary-of-terms
   
  and this:
http://www.head-fi.org/a/headphone-impedance


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## WiR3D

Updated


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## stv014

Quote: 





> Originally Posted by *Chris J* /img/forum/go_quote.gif
> 
> An impedance adaptor made up of one or two (or more) resistors will not decrease the output impedance of an amp.


 
   
  I have already explained this, but you are wrong. If you still do not believe, here is a simple test with a source that has 100 Ohm output impedance, and a 250 Ohm headphone. The left channel was connected directly to the headphone, but its level was reduced by 20 dB. On the right channel, I used a 680 Ohm potentiometer as a serial resistor, and a 27 Ohm parallel resistor. I adjusted the potentiometer so that the levels were matched. At that setting (~220 Ohm), the source "saw" a roughly similar impedance load on both channels. I have then created a frequency response and 40 Hz distortion graph, recording the voltage from the headphone. The result is:
    
  As you can see, the frequency response is nicely flattened out, and the THD is reduced by a factor of about 4. This is consistent with what would be expected from an output impedance reduction from 100 Ohm to 25 Ohm.


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## Chris J

Quote: 





wir3d said:


> Updated


 

 I think you mean you can use MORE sensitive IEMs with your high gain desktop amp.
  This is because the resistive network will decrease the apparent gain of the headphone amp


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## WiR3D

Quote: 





chris j said:


> I think you mean you can use MORE sensitive IEMs with your high gain desktop amp.
> This is because the resistive network will decrease the apparent gain of the headphone amp


 

 fixed


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## Chris J

Quote: 





stv014 said:


> I have already explained this, but you are wrong. If you still do not believe, here is a simple test with a source that has 100 Ohm output impedance, and a 250 Ohm headphone. The left channel was connected directly to the headphone, but its level was reduced by 20 dB. On the right channel, I used a 680 Ohm potentiometer as a serial resistor, and a 27 Ohm parallel resistor. I adjusted the potentiometer so that the levels were matched. At that setting (~220 Ohm), the source "saw" a roughly similar impedance load on both channels. I have then created a frequency response and 40 Hz distortion graph, recording the voltage from the headphone. The result is:
> 
> As you can see, the frequency response is nicely flattened out, and the THD is reduced by a factor of about 4. This is consistent with what would be expected from an output impedance reduction from 100 Ohm to 25 Ohm.


 

  
  Your reply is a bit rude.
   
  We agree that adding a 220 resistor reduces gain and reduces efficiency.
   
  You haven't listed you headphone amplifier (or source) or your headphone.
  What you have proven that adding a 27 ohm damping resistor in parallel with the headphone adds damping, therefore decreasing distortion. It is not the optimum damping value for every headphone.  Some headphones don't even require damping.
  You have also proven that adding a 27 ohm resistor in parallel with that headphone swamps out the effects of the impedance of the headphone (assuming the impedance varies with frequency) therefore smoothing out the frequecy response.
  You have proven that your resistive network mitigates the frequency and damping effects of high output impedance on that headphone, but you can't make the actual output impedance go away by adding more series and parallel resistance.


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## stv014

Quote: 





> Originally Posted by *Chris J* /img/forum/go_quote.gif
> 
> You have proven that your resistive network mitigates the frequency and damping effects of high output impedance on that headphone, but you can't make the actual output impedance go away by adding more series and parallel resistance.


 

 It depends on your definition of "output impedance", but you cannot deny that the resistor network achieves the same effect of increased electrical damping as a lower output impedance. And the output jack of the adapter (to which the headphones are connected) does have the lower output impedance - ~25 Ohm in this particular case - if I measure it as if it was the output of an amplifier.


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## WiR3D

Quote: 





stv014 said:


> It depends on your definition of "output impedance", but you cannot deny that the resistor network achieves the same effect of increased electrical damping as a lower output impedance. And the output jack of the adapter (to which the headphones are connected) does have the lower output impedance - ~25 Ohm in this particular case - if I measure it as if it was the output of an amplifier.


 

  
  Mmm so your stating that in my case with the d2k it will be a 20 or 24 ohm resistor, but with different headphones it will increase?
 interesting, what would be the rule of thumb regarding what those values should be taking into account output impedance and headphone impedance.
   
  EDIT: Please dont let this turn into an argument, you both have valid points


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## stv014

Quote: 





wir3d said:


> Mmm so your stating that in my case with the d2k it will be a 20 or 24 ohm resistor, but with different headphones it will increase?


 
   
  Yes, the choice of resistors depends on the headphones, but also on the source. Basically, the following need to be taken into account to find a good trade-off:
    - the intended effective output impedance (depends on the headphones)
    - the sensitivity of the adapter+headphone combination (i.e. the source should still be able to power it adequately)
    - the impedance of the adapter+headphone combination (should not be too low)


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## WiR3D

Quote: 





stv014 said:


> Yes, the choice of resistors depends on the headphones, but also on the source. Basically, the following need to be taken into account to find a good trade-off:
> - the intended effective output impedance (depends on the headphones)
> - the sensitivity of the adapter+headphone combination (i.e. the source should still be able to power it adequately)
> - the impedance of the adapter+headphone combination (should not be too low)


 

 Good to note.
  Ill update the main post now now.
  I'm about to ask a big favour 
   
  An idiots equation. Since many people reading this will probably not understand all the electrical stuff.
   
  So can come up with a basic enough enough equation that anyone can come here and find out what they need.


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## Chris J

Quote: 





stv014 said:


> It depends on your definition of "output impedance", but you cannot deny that the resistor network achieves the same effect of increased electrical damping as a lower output impedance. And the output jack of the adapter (to which the headphones are connected) does have the lower output impedance - ~25 Ohm in this particular case - if I measure it as if it was the output of an amplifier.


 

 I just agreed with you that the resistive network achieves the same effect as a lower output impedance.
  You're not the first guy to conduct an experiment, get some very good data, and draw an erroneous conclusion.
  Obviously you think I'm an idiot, I have no idea what I am talking about, so I'm outta here.


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## WiR3D

Quote: 





chris j said:


> I just agreed with you that the resistive network achieves the same effect as a lower output impedance.
> You're not the first guy to conduct an experiment, get some very good data, and draw an erroneous conclusion.
> Obviously you think I'm an idiot, I have no idea what I am talking about, so I'm outta here.


 

 Really? I think thats a bit childish, just calm down, and logically prove your point. With facts, links , equations or whatever, but nothing gets sorted by throwing a tantrum and leaving.


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## stv014

Quote: 





> Originally Posted by *Chris J* /img/forum/go_quote.gif
> 
> You're not the first guy to conduct an experiment, get some very good data, and draw an erroneous conclusion.


 
   
  I did not draw the conclusion from the experiment. I did the experiment to demonstrate that the theory is correct (of which I was already 100% sure), and that it achieves the intended effect in practice.


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## Chris J

stv014 said:


> I did not draw the conclusion from the experiment. I did the experiment to demonstrate that the theory is correct (of which I was already 100% sure), and that it achieves the intended effect in practice.





 
 
 I am not disputing your theory outright. Just one small point. To recap: Your theory was that if you add a DAMPING resistor across the headphone it may be possible to compensate for the very low DAMPING FACTOR you are seeing from your 100 ohm source and your 250 ohm headphone combination. Since you have added a damping resistor across the headphone you have done two things: 1. reduced the distortion. 2. flattened out the voltage applied across the headphone. This would be even more pronounced with headphones having wild impedance swings across the audio badwidth. The 27 ohm resistor swamps out any impedance variations you may have in your headphone. So in practice it acheives the intended effect. It is a very fine point I am making: the amp output impedance is now 100 + 220 ohms = 320 ohms. i.e. add the original source impedance to the impedance of the resistor in series with the load. This is the definition of output impedance. One way you can see this because you had to reduce the gain of the other channel by 20 dB to match the losses in the channel with the resistor network. Please note that I am NOT disputing your results! I am only disputing one minor point! That point is: have you reduced output impedance? No. The experiment answers a VERY interesting question: can you compensate for a high output impedance with a resistive network? If you are referring to damping factor then, Yes! If you want to reduce the frequency variations caused by the high output impedance then you can also do this. This is NOT a simple subject by any means. YMMV with other headphones and other resistor values. But the network causes losses so you had to reduce the gain of the other channel by 20 dB.


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## Steve Eddy

Quote: 





chris j said:


> It is a very fine point I am making: the amp output impedance is now 100 + 220 ohms = 320 ohms.i.e. add the original source impedance to the impedance of the resistor in series with the load.This is the definition of output impedance.


 
   
  That's incorrect.
   
  If the amplifier's output impedance is 100 ohms, and you shunt that with a 220 ohm resistor, then the amplifier's effective output impedance isn't the series combination of those two values but rather the parallel combination of those two values, or 68.75 ohms, not 320 ohms.
   
  And as for lowering distortion, the amplifier will see the parallel combination of the 220 ohm resistor and the 250 ohm headphones, which would be 117 ohms, instead of the 250 ohms it would see otherwise. So now the amplifier has a somewhat heavier load to drive and all else being equal, distortion will tend to increase.
   
  se


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## Chris J

Quote: 





steve eddy said:


> That's incorrect.
> 
> If the amplifier's output impedance is 100 ohms, and you shunt that with a 220 ohm resistor, then the amplifier's effective output impedance isn't the series combination of those two values but rather the parallel combination of those two values, or 68.75 ohms, not 320 ohms.
> 
> ...


 


 Not even close.............


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## Steve Eddy

Quote: 





chris j said:


> Not even close.............


 

 No, it's quite spot on.
   
  If you have an amplifier with a 100 ohm output impedance, and across that amplifier's output you add a 220 ohm resistor, the output impedance as seen by the load is the parallel combination of those two values.
   
  You need to brush up on basic circuit analysis. Remember, in the Thevenin analysis, voltage sources are shorted. That places the amplifier's 100 ohm output impedance in parallel with the 220 ohm resistor across the amplifier's output, not in series with it. So looking into the amplifier's output, you see 68.75 ohms, not 320 ohms. And 68.75 ohms is lower than the amplifier's 100 ohm output impedance.
   
  se


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## Chris J

Quote: 





steve eddy said:


> No, it's quite spot on.
> 
> If you have an amplifier with a 100 ohm output impedance, and across that amplifier's output you add a 220 ohm resistor, the output impedance as seen by the load is the parallel combination of those two values.
> 
> ...


 


 You are grossly misapplying Thevinin's Theorem.
  Read the thread again.
  Read up on Thevenin again.
  STV took a source with a 100 ohm output impedance.
  Then he added a 220 ohm resistor in series with the load.
  100 + 220 = 320 ohms.
  The load is a 250 ohm 'phone in parallel with a 27 ohm resistor.
  Thevenin's Theorem does not apply as the "black box" (i.e his source) has only one Voltage source and a defined output impedance of 100 ohms. 
  Like I said, from the load's point of view the output terminals are across the parallel combination of the headphone and the 27 ohm resistor.


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## Steve Eddy

Quote: 





> Originally Posted by *Chris J* /img/forum/go_quote.gif
> 
> Then he added a 220 ohm resistor in series with the load.


 

 Ok. You'd said "Since you have added a damping resistor _*across the headphone*_ you have done two things..." I thought you meant it was the 220 ohm resistor across the headphones. Sorry.
   
  Quote: 





> The load is a 250 ohm 'phone in parallel with a 27 ohm resistor.


 
   
  Ok. So if he's got a 27 ohm resistor in parallel with the headphones, that means it's also across the amplifier's output. So the effective output impedance of the amplifier, i.e. the source impedance seen by the headphones, will be much lower still.
   
  Quote: 





> Like I said, from the load's point of view the output terminals are across the parallel combination of the headphone and the 27 ohm resistor.


 
   
  If we consider the headphone to be the load, then the headphone is effectively seeing an amplifier with an output impedance of about 25 ohms, i.e. 100 + 220 in parallel with 27.
   
  se


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## Chris J

Quote: 





steve eddy said:


> Ok. You'd said "Since you have added a damping resistor _*across the headphone*_ you have done two things..." I thought you meant it was the 220 ohm resistor across the headphones. Sorry.
> 
> 
> Ok. So if he's got a 27 ohm resistor in parallel with the headphones, that means it's also across the amplifier's output. So the effective output impedance of the amplifier, i.e. the source impedance seen by the headphones, will be much lower still.
> ...


 

 No problem.
   
  If he has the 27 ohm resistor in parallel with the headphones, then the headphones appear to be a 24 ohm load.
  For this parallel combination, obviously the 27 ohm resistor will pull more output current than the 250 ohm headphone.
   
  The headphone amp appears to have a 320 ohm output impedance because the 220 ohm resistor is in series with the headphone amp's original output impedance of 100 ohms.
  So we have increased the output impedance.
  STV014's experiment added a 27 ohm damping resistor across the headphone, he used this damping to counter the effects of the high output impedance (assuming the headphone you are using needs damping!).
   
  Another way to look at this is: assume the headphone amp is an ideal voltage source with ALL the other impedances outside the headphone amp.
  The IDEAL voltage source (i.e.headphone amp in this discussion) has Zero output impedance.
  Then the load on the IDEAL headphone amp appears to be 100 + 220 + 24 = 344 ohms.  So we may now calculate how much TOTAL current is drawn from the amp.
  With a little bit of calculation (using Voltage divider principle) and power calcs we can also see that the efficiency of this whole network is very poor, i.e very little output voltage is actually applied across the headphone.  And most of the output current is flowing thru a 27 ohm resistor!
   
  I can very easily see how this confuses everyone!
	

	
	
		
		

		
			




   
  C


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## WiR3D

You have that correct, i am a bit lost, I am going to reread this, but only later when I have time, but please continue to discuss it  Chris J your input has been very valuable, thank you.
   
  It also may be worth stating the risks involved here, again, where others can read it.


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## Steve Eddy

Quote: 





> Originally Posted by *Chris J* /img/forum/go_quote.gif
> 
> If he has the 27 ohm resistor in parallel with the headphones, then the headphones appear to be a 24 ohm load.


 
   
  The headphone appears to be a 24 ohm load relative to what exactly?
   
  With the configuration given, the amplifier sees a load of 220 ohms plus the parallel combination of 27 and 250 ohms, or about 244 ohms.
   
  Quote: 





> For this parallel combination, obviously the 27 ohm resistor will pull more output current than the 250 ohm headphone.


 
   
  It won't be much. You're only talking about a 6 ohm difference. Given, say, a 2 volt output, the 250 ohm headphone will draw 5.7mA (accounting for the amplifier's 100 ohm output impedance). With the headphone and the resistor network, it will draw 5.8mA. So you're talking about a difference of 0.1mA.
   
  Quote: 





> The headphone amp appears to have a 320 ohm output impedance because the 220 ohm resistor is in series with the headphone amp's original output impedance of 100 ohms.


 
   
  No, the headphone amp appears to have an output impedance of 24.9 ohms. You're leaving out the 27 ohm resistor that is across the amplifier's output. And that's what, in this case anyway, largely defines the headphone amplifier's effective output impedance.
   
  Quote: 





> So we have increased the output impedance.


 
   
  No. The output impedance has not been increased. From the perspective of the headphones, which is the only perspective of any meaning here, the amplifier's output impedance drops from 100 ohms to 24.9 ohms.
   
  Quote: 





> STV014's experiment added a 27 ohm damping resistor across the headphone, he used this damping to counter the effects of the high output impedance (assuming the headphone you are using needs damping!).


 
   
  You keep overlooking the fact that the 27 ohm resistor is not just across the headphone but also across the headphone amp's output. And as such, it defines the headphone's output impedance as seen by the headphone.
   
  Quote: 





> Another way to look at this is: assume the headphone amp is an ideal voltage source with ALL the other impedances outside the headphone amp.


 
   
  Which is precisely how I was looking at it.
   
  Quote: 





> The IDEAL voltage source (i.e.headphone amp in this discussion) has Zero output impedance.


 
   
  Yes.
   
  Quote: 





> Then the load on the IDEAL headphone amp appears to be 100 + 220 + 24 = 344 ohms


 
   
  Yes.
   
  Quote: 





> So we may now calculate how much TOTAL current is drawn from the amp.


 
   
  Yes.
   
  Quote: 





> With a little bit of calculation (using Voltage divider principle) and power calcs we can also see that the efficiency of this whole network is very poor, i.e very little output voltage is actually applied across the headphone.  And most of the output current is flowing thru a 27 ohm resistor!


 
   
  Yes.
   
  But since when was the issue efficiency?
   
  The issue was your claim that a resistor network could not reduce the effective output impedance of the amplifier. And that's simply not the case as even basic circuit analysis here shows.
   
  If you take your ideal voltage source and add a 100 ohm resistor in series with its output and you've got an amplifier with a 100 ohm output impedance. Add the 220 ohm series and 27 ohm shunt resistors and you now have an amplifier with a 24.9 ohm output impedance just as sure as I'm sitting here. That's the source impedance that the headphone will see and it will behave just as it would if it were being driven from an amplifier without the network and an inherent output impedance of 24.9 ohms.
   
  se


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## WiR3D

Just to note the efficiency claim comes from stv014 who is actually using that adapter, I am sure he also noted that he needs to increase his volume levels.


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## Steve Eddy

Quote: 





wir3d said:


> Just to note the efficiency claim comes from stv014 who is actually using that adapter, I am sure he also noted that he needs to increase his volume levels.


 

 Yes, he mentioned that in his post with the graphs. With an amp with 100 ohm output impedance, a resistive network with a series 220 ohm resistor and a shunt 27 ohm resistor and 250 ohm headphones, you lose 20dB compared to without the network.
   
  se


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## WiR3D

Steve Eddy, chris and i had a nice chat in private, and (I am going to paraphrase, which means it could be incorrect) he mentioned something about certain amps being designed to have high output impedances as a safety factor, and that lowering it can be dangerous?
   
  Also the TI headphone amp in the Asus STX is designed for a 10 ohm output resistance, so could lowering it be bad for my sound card?


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## stv014

Quote:  





> Also the TI headphone amp in the Asus STX is designed for a 10 ohm output resistance, so could lowering it be bad for my sound card?


 

 Not if the sound card still sees a reasonably high impedance load. That is why the adapter includes a serial resistor as well, not just a parallel one. The output impedance of the amplifier itself is not changed, only what is seen from the headphone. Let's say we have an adapter with a 24 Ohm serial, and a 4.7 Ohm parallel resistor, the headphone impedance is 25 Ohm, and the card has an output impedance of 10.5 Ohm. This means that:
    - the amplifier sees a load of 10.5 + 24 + 1/(1/4.7+1/25) = 38.46 Ohm (i.e. the headphone+adapter combination is ~28 Ohm)
    - the headphone sees an output impedance of 1/(1/4.7+1/(10.5+24)) = 4.14 Ohm
    - the damping factor is increased from 2.38 to 6.04
    - maximum voltage on the headphone is (with 7 Vrms output from the TPA6120): 7 / (1/4.7+1/25) / 38.46 = 0.72 Vrms
    - this is enough for a maximum SPL of 90+20*log10(0.72/0.064) = 111 dB (more power?)
    - the maximum current (with sine output) is 0.72 * (1/4.7+1/25) = 0.182 Arms
    - power dissipation on the serial resistor is 24 * 0.182^2 = 0.795 W (at least 1 W resistor is needed)
    - check here for some idea on how the TPA6120 is likely to perform with a 28 Ohm load
    - the worst case power dissipation on the TPA6120, with +/- 12V supply voltage and 6 V square wave output, is 6^2 / 38.46 = 0.936 W per channel. This may be of concern if the chip is not well cooled, although in practice with realistic music signals and listening volumes the power is likely to be less
  Hopefully the power supply on the STX (particularly the negative rail) is good enough to actually output enough current at the maximum voltage with this load, this cannot be verified from the available information.
  By the way, this headphone+adapter combination is only about twice as efficient overall as the Hifiman HE-6.


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## Steve Eddy

Quote: 





wir3d said:


> Steve Eddy, chris and i had a nice chat in private, and (I am going to paraphrase, which means it could be incorrect) he mentioned something about certain amps being designed to have high output impedances as a safety factor, and that lowering it can be dangerous?


 
   
  Well, one example of that would be my TEAC A-H500 50 watt integrated amplifier. The headphone output is driven straight off the loudspeaker outputs through a pair of 390 ohm resistors. That's so that if you've got the amp cranked up and are pumping 50 watts into a pair of 8 ohm speakers, if you plug in say, a pair of 50 ohm LCD-2's, they'll only be driven by about 100mA instead of 566mA. However using the impedance adapter described here wouldn't lower the amp's output impedance in the same way as if those 390 ohm resistors were replaced with 24.9 ohm resistors. In other words, Chris J's concerns are unfounded.
   
  se


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## WiR3D

Quote: 





steve eddy said:


> Well, one example of that would be my TEAC A-H500 50 watt integrated amplifier. The headphone output is driven straight off the loudspeaker outputs through a pair of 390 ohm resistors. That's so that if you've got the amp cranked up and are pumping 50 watts into a pair of 8 ohm speakers, if you plug in say, a pair of 50 ohm LCD-2's, they'll only be driven by about 100mA instead of 566mA. However using the impedance adapter described here wouldn't lower the amp's output impedance in the same way as if those 390 ohm resistors were replaced with 24.9 ohm resistors. In other words, Chris J's concerns are unfounded.
> 
> se


 
   
  Thank you once again for the input,
  And i wouldn't say unfounded, reading it over again he was more specifically referring to changing the resister before the output jack, if there is one.

 But now that I have the equations I can update the main post. Thank you stv014
   
  Thank you


----------



## WiR3D

updated, when i get time i will redo the equations into step by step fashion, but not now


----------



## Steve Eddy

Quote: 





wir3d said:


> Thank you once again for the input,
> And i wouldn't say unfounded, reading it over again he was more specifically referring to changing the resister before the output jack, if there is one.


 

 Ah, ok. Yes, if you're talking about reducing the output impedance of an amplifier that's using an output resistor to limit output by reducing or removing that resistor, that's a whole other matter and agree with Chris J on that.
   
  se


----------



## WiR3D

Quote: 





steve eddy said:


> Ah, ok. Yes, if you're talking about reducing the output impedance of an amplifier that's using an output resistor to limit output by reducing or removing that resistor, that's a whole other matter and agree with Chris J on that.
> 
> se


 

 I am adding you to the thanks list


----------



## Steve Eddy

Quote: 





wir3d said:


> I am adding you to the thanks list


 


 Oh don't bother. Just another mouth to feed. 
	

	
	
		
		

		
		
	


	



   
  se


----------



## Chris J

Quote: 





steve eddy said:


> Well, one example of that would be my TEAC A-H500 50 watt integrated amplifier. The headphone output is driven straight off the loudspeaker outputs through a pair of 390 ohm resistors. That's so that if you've got the amp cranked up and are pumping 50 watts into a pair of 8 ohm speakers, if you plug in say, a pair of 50 ohm LCD-2's, they'll only be driven by about 100mA instead of 566mA. However using the impedance adapter described here wouldn't lower the amp's output impedance in the same way as if those 390 ohm resistors were replaced with 24.9 ohm resistors. In other words, Chris J's concerns are unfounded.
> 
> se


 


 Looks like you read 50% of the thread and understood 85% of it.
  In addition, there is a difference between output impedance and reactive load damping.


----------



## Steve Eddy

Quote: 





chris j said:


> Looks like you read 50% of the thread and understood 85% of it.
> In addition, there is a difference between output impedance and reactive load damping.


 

 Not from the perspective of the headphones there isn't. Sorry.
   
  se


----------



## WiR3D

Right I finally got around to testing it. The first version has a glitch, and the left side works but the right was monumentally messed up.
   
  So to test the concept I created a franken-circuit, excuse the crappy photos.

   
  I used (per channel) 2x 47ohm 0.75w resisters in parallel since I couldn't find any 24ohm resisters that could carry the current
  and 1x 4.7ohm 0.6w resister
   
  And wow it really does waste power, I haveto put the STX on extra high but at 40% max.
  I am running 2x AD797BR opamps, which nullifies the crappy bass of the JRC, but retains the sharpness (which I dont like, but it helps identify differences) and increases clarity.
   
  Overall I notice the highs are back to normal, which is still bright in the D2000, but thankfully not painful, it actually makes the aggressive sound of the AD797 bearable.
  I dont know if its affecting the SQ, I have a feeling it is but it could very well be my franked adapter, It should improve when I solder it in place, or its just that the AKG K242HD has some serious synergy with the AD797.
  Bass is still as hard hitting as ever, but its definately clearer and not there when not needed.
   
  whether its worth the effort.... I wouldn't say it isn't, but I wouldnt say it is.
   
   
   
  Since I have some spare power to play with, can I bump up/down the resistor values to get a stronger effect (lower output resistance) ?
   
  EDIT: I would say I have exactly 50% more power then I am using now to waste before I put stress on the STX components (keeping volume lower then 76)


----------



## Chris J

Quote: 





wir3d said:


> Right I finally got around to testing it. The first version has a glitch, and the left side works but the right was monumentally messed up.
> 
> So to test the concept I created a franken-circuit, excuse the crappy photos.
> 
> ...


 
   
  Sure,  trying increasing or decreasing the 4.7 ohm resistor.
  The value will not be the same for both headphones.
  You can probably just delete "Franken-circuit" with the AKGs.
   
  BTW what does the STX and either 'phone sound like without "Franken-circuit"?
   Just want to get some impressions of the AD797............
   
  I've noticed that some of the AKG Q701 guys like the STX but you should be warned that some people think the Q701 is a bright 'phone!


----------



## WiR3D

Quote: 





chris j said:


> Sure,  trying increasing or decreasing the 4.7 ohm resistor.
> The value will not be the same for both headphones.
> You can probably just delete "Franken-circuit" with the AKGs.
> 
> ...


 

 No I am not using the K242 with the franken-circuit, I really do think it has an affinity, clarity wise, with the AD797, its harsh but it seems my brain compensates after a while, it has insane imaging and a big soundstage, it is warm with the K242, and intimate, and has an intoxicating heroin-like effect with its clarity when matched with the K242, but I do think the highs are a bit much, but that could be due to the treble spike in the FR of the K242. On a side note the THS4032 is 90% the AD797 but with a smooth sound signature.
   
  The k242 already eats way too much power anyway so I doubt I will get enough power to it, I will try later though.
  I'm going to play with the math now now aswell and see what numbers I get


----------



## Staal

Hey guys!
   
  I'm stuck with an issue I figured might be relevant to this whole debate.
   
  I'm currently using PC --> Foobar / (WASAPI) --> Coax cable --> Yulong D100 --> JH16 / Heir Audio 8.A. It sounds great, but I'm having trouble adjusting the volume. If I leave Foobar at it's max (which is the standard), my CIEMs are so loud I cannot listen to them even at the lowest ticks on the volume knob of the D100. I assume this is because both of my custom IEMs are relatively sensitive (26 ohm impedance iirc)
   
  Obviously dampening the volume in Foobar solves this, and with around -18dB in Foobar I'm able to go up a few ticks on the D100 (nowhere near 1/4 of the potential though). I keep thinking that dampening the digital signal might be a bad idea for the SQ and ideally I'd have Foobar's volume at it's maxed standard and my D100 much less brutal to my CIEMs meaning I could adjust volume to my specific needs rather than settling for "a bit too quiet" or "way too high".
   
  Would an impedance adapter from say Apuresound fix this, or do I need to go a different route?
   
  Thanks in advance.


----------



## WiR3D

So just to catch everyone else up Staal, I'm going to repeat myself.
   
  A normal output increasing adapter should do the job, but i keep hearing reports that it affects the sound, which makes sense since it pretty much introduces an impedance mismatch.
   
  Chris J I was busy thinking that the same type of parallel circuit i am using will do a good job at wasting power, but will it actually work in this application? it may make them more sensative to noise...


----------



## Chris J

Quote: 





staal said:


> Hey guys!
> 
> I'm stuck with an issue I figured might be relevant to this whole debate.
> 
> ...


 
   
  Do you have any idea how much gain the Yulong has?
  I really don't know much about the Yulong but I will guess that it has approx. 20 dB of gain.   Does it have adjustable gain?
  I am no expert on IEMs but I do have a pair of Shure SE210 IEMs (they sound rather crappy............the bass is AWOL).
  I plugged them into my Matrix M Stage, the M Stage can be set to a gain of 0, 10 18 or 20 dB.
  At 20 dB I had the problem you describe, very little control over the volume and the control is at approx. 8 o'clock.
  There is also a fair amount of hiss coming from the amp.    
	

	
	
		
		

		
			




  At 0 dB gain I have some control over the volume and have usable range from approx. to 12 o'clock.
   
  Quote: 





wir3d said:


> A normal output increasing adapter should do the job, but i keep hearing reports that it affects the sound, which makes sense since it pretty much introduces an impedance mismatch.
> 
> Chris J I was busy thinking that the same type of parallel circuit i am using will do a good job at wasting power, but will it actually work in this application? it may make them more sensative to noise...


 
   
  I've heard some people say that an in-line resistor is a good idea and I've heard other people say that you get too much hiss from some amps................YMMV!


----------



## WiR3D

OOOOOO wait I just had a crazy idea. How about both?
   
  An inline resister to increase the noise floor with the sideffect of introducing an impedance mismatch, and then the faux impedance decreasing adapter, that will waste power and counteract the negative effects of the impedance mismatch. In theory anyway


----------



## Chris J

Quote: 





wir3d said:


> OOOOOO wait I just had a crazy idea. How about both?
> 
> An inline resister to increase the noise floor with the sideffect of introducing an impedance mismatch, and then the faux impedance decreasing adapter, that will waste power and counteract the negative effects of the impedance mismatch. In theory anyway


 
   
  I think the problem is usually too much hisssssssss.
	

	
	
		
		

		
		
	


	



  Adding another resistor will not reduce the nassssssssty hissssss.
	

	
	
		
		

		
		
	


	



  That's my theory, anyway.
   
  I've heard a lot of guys say they don't like the sound of "digital damping".
  Staaal, what does it say in the Yulong manual about reducing the Analog gain of the headphone amp in the Yulong?


----------



## Staal

Quote: 





chris j said:


> I've heard a lot of guys say they don't like the sound of "digital damping".
> Staaal, what does it say in the Yulong manual about reducing the Analog gain of the headphone amp in the Yulong?


 
   
  It doesn't really mention anything regarding the issue.


----------



## Chris J

Quote: 





wir3d said:


> OOOOOO wait I just had a crazy idea. How about both?
> 
> An inline resister to increase the noise floor with the sideffect of introducing an impedance mismatch, and then the faux impedance decreasing adapter, that will waste power and counteract the negative effects of the impedance mismatch. In theory anyway


 
   
  Come to think of it,
  any attentuator (in line resistor) that attenuates the signal will also attenuate the hiss.
   
  I don't think I would bother adding a resistor in parallel with the headphone.
  Apparently most IEMs are very simple loads and don't need the resistor in parallel.
  But you can try it out..................you never know.


----------



## WiR3D

well the whole point of the inline resisters (output impedance INCREASING adapters) is too raise the noise floor for IEMs, which it should do.
   
  But it introduces an impedance mismatch. But Staal just buy one, it will do what you want, just be warned the side effect is colouration and possible loss of clarity.


----------



## WiR3D

Right I just did the Math.
   
  If I drop the parallel resistor to 2.21ohms then the following results:
   
   
  Amp load: 38~39 ohms (this will never really change)
  Output impedance(from headphone perspective): 2.07ohms
  Maximum output Vrms: 0.37
  Maximum output Arms: 0.182
  SPL:105dB
   
  so I will have more then enough power in my opinion anyway. and then this pushes the impedance balance over the 10/1 barrier.
   
  I'm doing it


----------



## Chris J

Quote: 





wir3d said:


> well the whole point of the inline resisters (output impedance INCREASING adapters) is too raise the noise floor for IEMs, which it should do.
> 
> But it introduces an impedance mismatch. But Staal just buy one, it will do what you want, just be warned the side effect is colouration and possible loss of clarity.


 
   
  I think you mean drop the noise floor, lower the noise floor, reduce the level of the noise?????????


----------



## WiR3D

Quote: 





chris j said:


> I think you mean drop the noise floor, lower the noise floor, reduce the level of the noise?????????


 
  yes that


----------



## ExpatinJapan

Etymotic ER4P -> ER4S adapter $50 75 Cabled

   
  I have this one.


----------



## Yazi

sorry for my poor english
   
  I just wonder if you see this post?
   
http://www.anythingbutipod.com/forum/showthread.php?t=30962
   
  It seem adding a impedence adapter (as u mention before, UE's impedence adapter) will fix the bass roll-off issues with the D2.
   
  As you mention that impedance mismatching will result less bass response than the original design, or high frequency noise.
   
  D2 have higher output impedance and get bass roll-off.
   
  However, in their case, add a impedence adapter will end up with less bass rolled-off, and the background hiss disappears.
   
  Moreover, in this post http://www.head-fi.org/t/544478/ultimate-ears-ue-x-pro-custom-appreciation-review-discussion-thread/45 (post #54 )
   
  UE try to fix the impedance mismatching with a impedance adapter. 
(They had claimed that UERM's attenuator is different from TF's.)
   
   
  May you give me a detail review, thanks.
   
   
  Best,
   
  Yazi


----------



## WiR3D

Quote: 





yazi said:


> sorry for my poor english
> 
> I just wonder if you see this post?
> 
> ...


 
  You are half right, you want to DECREASE the output impedance, so that adapter wont work, I had to build my own.
   
  You want the "*Faux impedance decreasing adapter*" as explained on page one. I have yet to see where I can buy one.


----------



## Yazi

Thank for your reply 
   
  I just don't know why their solution (for impedance mismatching) is adding an impedance adapter (add more output impedance) to player.
   
  In your post, you all say adding an impedance adapter to player will end up with higher output impedance. (that seems right, at least for me.)
   
   
  Does that mean damping factor is more lower? (getting more bass roll-off or ?)
   
  However, their solution seem to fix this issues. Why?
   
  There must be an explanation, right?
   
  Therefore, I ask your help  
   
   
  again, thank for you reply.
   
   
  Best,
   
  Yazi


----------



## WiR3D

aaaa, the problem is I don't know how dampening factor correlates to bass roll off.
   
  Quote: 





yazi said:


> Thank for your reply
> 
> I just don't know why their solution (for impedance mismatching) is adding an impedance adapter (add more output impedance) to player.
> 
> ...


 
  aaa, you will haveto wait for Chris J or stv014 to reply with specifics.
   
  TBH I kind of ignored the bass roll off comment, and now it seems there is more to it then I thought.
   
  When you decrease the output impedance, you get less colouration, cleaner bass, and more micro details and a HIGHER dampening factor.
   
  When you increase output impedance its pretty much the opposite, but you also raise the noise floor.
   
   
  But like I said, I don't know how dampening factor correlates to bass roll off,


----------



## Chris J

Quote: 





yazi said:


> Thank for your reply
> 
> I just don't know why their solution (for impedance mismatching) is adding an impedance adapter (add more output impedance) to player.
> 
> ...


 
   
  Hmmmm, I guess you must have an output coupling capacitor in your headphone amplifier?
  If you do have a headphone amp with an output coupling capacitor then you may be getting some audible bass frequecy roll-off:  the output capacitor is acting as a high pass filter.
  For example, That is one of the reasons why I *CAN* use my 600 headphones with my capacitor coupled OTL tube amp but *CAN'T* use my 62 ohm 'phones with my capacitor coupled OTL tube amp.
   
  Can you be more specific?
  What kind of headphones are you using?   I'm not too bright, I don't know what a D2 is!
	

	
	
		
		

		
			




  And what kind of headphone amplifier are you using?
  And which one of those resistor adaptors are you using?
   
  thx,
  Chris


----------



## Yazi

Quote: 





chris j said:


> Hmmmm, I guess you must have an output coupling capacitor in your headphone amplifier?
> If you do have a headphone amp with an output coupling capacitor then you may be getting some audible bass frequecy roll-off:  the output capacitor is acting as a high pass filter.
> For example, That is one of the reasons why I *CAN* use my 600 headphones with my capacitor coupled OTL tube amp but *CAN'T* use my 62 ohm 'phones with my capacitor coupled OTL tube amp.
> 
> ...


 
   
  Hi Chris,
   
  I don't have Cowon D2. I just see their post.
   
  Here : http://www.anythingbutipod.com/forum/showthread.php?t=30962
   
In their post, add a impedence adapter end up with less bass rolled-off, and the background hiss disappears.
   
Moreover, UE try to fix the impedance mismatching with a impedance adapter.
   
See here: http://www.head-fi.org/t/544478/ultimate-ears-ue-x-pro-custom-appreciation-review-discussion-thread/45(post #54 )
   
  I wonder what is happen, so I ask for ur help 
   
   
  Best,
   
  Yazi


----------



## Chris J

Quote: 





yazi said:


> Hi Chris,
> 
> I don't have Cowon D2. I just see their post.
> 
> ...


 
   
  I will try to explain.
   
  It would seem that:
  The UE has a low impedance,  and the D2 probably has an output coupling capacitor
   
  if the impedance of the UE is too low and the coupling capacitor in the D2 is too low (too small) then it is possible that the interaction will cause the low bass to roll off.
   
  if you add the "impedance adaptor" then the load impedance increases so you get less bass roll off.
   
  also if you add the impedance adaptor the sound level coming out of the D2 drops so the level of the hiss also drops.
  The UE are very efficient so any hiss created by the D2 is easily heard thur the UEs
   
  It all makes sense.
   
  Not too sure if armature earphones like UEs really need to be driven by a low output impedance to sound their best.


----------



## WiR3D

nice writeup chris  
   
  I should post that i put 2 4.7ohm resistors in parallel in the parallel section, was an even better end result. I dont think it will get much better now, but 4ohm output was definately not enough, 2.1ohm is much better.
  was tricky as hell fitting 8 resistors into the neutrik female jack.


----------



## Chris J

wir3d said:


> nice writeup chris
> 
> I should post that i put 2 4.7ohm resistors in parallel in the parallel section, was an even better end result. I dont think it will get much better now, but 4ohm output was definately not enough, 2.1ohm is much better.
> was tricky as hell fitting 8 resistors into the neutrik female jack.




Thanks Mr. Wire!

BTW I'm glad the franken circuit is working out for you!


----------



## WiR3D

Quote: 





chris j said:


> Thanks Mr. Wire!
> BTW I'm glad the franken circuit is working out for you!


 
  the franken circuit was confined to the toolbox, for later experiments. its now in its final form.
  I'm gonna upload pictures eventually lol.
   
  this is gonna be funny, but it makes a bigger difference then changing opamps, and its the opposite with my AKGs.


----------



## Yazi

Hi Chris, 
   
   
  Thank for your reply 
   
  I'm not sure I fellow through this thread completely.
   
  You mean if I add the "impedance adaptor" then the load impedance increases?
   
  According your previous posts, when I add a impedance adaptor then the output impedance increases, am I right?
   
  The higher the output impedance, the larger variations in the frequency response, especially balanced armature.
   
   I just want to know what will happen when I add a impedance adaptor to a playback device?
   
  Will it increase load or output impedance?

   
   
In addition, 
   
when I add the "impedance adaptor" form my UERM pack, I get a more tight bass.
   
  However, when I add the "attenuator" form TF10s, I get a bit uncontrolled and more rumble bass.
   
   
   
  Best,
   
  Yazi


----------



## WiR3D

its because of the *coupling capacitor*
   
it changes things


----------



## Yazi

Thank for your reply 
   
  Could you explain more about the role of coupling capacitor in this circumstance?
   
  I am just curious about how the coupling capacitor effect output impedance.
   
  Many thanks 
   
   
  Best,
   
  Yazi


----------



## WiR3D

reread Chris J's post I only just get it.


----------



## Steve Eddy

Quote: 





yazi said:


> Thank for your reply
> 
> Could you explain more about the role of coupling capacitor in this circumstance?
> 
> I am just curious about how the coupling capacitor effect output impedance.


 
   
  Capacitive reactance.
   
  Capacitive reactance, which is measured in ohms just as resistance is, is 1/(2piFC) where F is frequency in Hz and C is capacitance in Farads. As frequency goes down, reactance goes up. Reactance also goes up as capacitance gets smaller. Which is why, when you're driving relatively low impedance loads, you want a larger capacitance than if you were driving a higher impedance load as the output impedance forms a voltage divider with the load.
   
  se


----------



## Chris J

Quote: 





yazi said:


> Hi Chris,
> 
> Thank for your reply
> I'm not sure I fellow through this thread completely.
> ...


 
   
  Hello Yazi,
   
  Short version:
   
  I can't tell exactly what value resistors are actually in the impedance adaptors, but at the risk of starting World War III (LOL!), I can tell you that without a doubt you are increasing the output impedance of the amp.
  Or to put it another way, you are increasing the load impedance.
  In really simple terms, it works out to the same thing, as far as you are concerned.
  Easiest way to verify this is to try the 'phones with and without an impedance adaptor.
  If adding an impedance adaptor decreases the volume then you are undoubtledly increasing the Output Impedance by adding the impedance adaptor from the 'phones point of view.
  But the amp also sees it as an increase in Load Impedance.
   
  Sounds like the impedance adaptor form the UERM pack is the same or very similar to Wired's "Franken Circuit".  Sounds like this is the one to go with. Like Franken Circuit, the UERM adaptor has stuff in it to counter-effect the effects of high output impedance.  I assume this adaptor also reduces hiss and volume?
   
  The impedance adaptor from TF10s is probably just a resistor in series with the 'phones. I assume this reduces hiss and decreases volume?
   
  Confused yet?
	

	
	
		
		

		
			




   
  BTW, I am an Electrical Engineer with approx. 25 years experience with Power Distribution, Power Conditioning, Power Conversion and Analog Signal Processsing.
  For a reality check, I asked a few of the Electrical Power Distribution guys whom I work with if the adaptor increases the output impedance of the amp, they all said yes.
   
  CJ
   
  .


----------



## manveru

Quote: 





wir3d said:


> the franken circuit was confined to the toolbox, for later experiments. its now in its final form.
> I'm gonna upload pictures eventually lol.
> 
> this is gonna be funny, but it makes a bigger difference then changing opamps, and its the opposite with my AKGs.


 
   
  Any updates? Pics?


----------



## WiR3D

Quote: 





manveru said:


> Any updates? Pics?


 
  Been using it exclusively. its amazing. A MUST HAVE with the Denons especially my newish D7000. Sorts out the bass, and reveals micro details. Pairs nicely with 2x TH4032 Opamps in the I/V section of the card. They could be oscillating but I don't give a damn. An this adapter eats so much power any DC offset is null and void.
   
  Pictures will be boring ill post now now. Had to fit 8 resistors in, because I didn't want to wat for 2.21~ohm resistors. so i put two 4.7ohm resistors in parallel in the parallel section. was crazy. For future reference the MALE neutrik 1/4" jack has more space then the female 1/4"inch.


----------



## WiR3D




----------



## manveru

Quote: 





wir3d said:


>


 
   
  Looks neat. Something like this would really come in handy for me, but the only way is to make one yourself right? I don't have any DIY knowledge/skills. -__-


----------



## WiR3D

Quote: 





manveru said:


> Looks neat. Something like this would really come in handy for me, but the only way is to make one yourself right? I don't have any DIY knowledge/skills. -__-


 
  Don't worry DIY cables and adapters are much easier then you think. My father tought me how to solder.
  This was only my third thing I made, and you never know, you may like it. 
   
  The downside you need a fairly good multimeter, a solder, and all the bits.


----------



## manveru

Quote: 





wir3d said:


> Don't worry DIY cables and adapters are much easier then you think. My father tought me how to solder.
> This was only my third thing I made, and you never know, you may like it.
> 
> The downside you need a fairly good multimeter, a solder, and all the bits.


 
   
  I probably would like it. I won't have any money for tools/supplies for a while though. I should get into it eventually as I'm sure it would come in handy a lot.


----------



## WiR3D

Quote: 





manveru said:


> I probably would like it. I won't have any money for tools/supplies for a while though. I should get into it eventually as I'm sure it would come in handy a lot.


 
  I think it is worth it, it really is fun, and nice to get your hands busy and actually build something physical.


----------



## paaj

Thanks for the list, I've been searching for these adapters to get the Q701 in line (designed for 120 ohm output I believe) and they are hard to find pre-made.


----------



## Impulse

Really interesting stuff, I'm surprised the thread hasn't garnered more posts... I have an STX too and I'm curious to try my hand at a similar adapter in order to improve it's performance with some of my other headphones. I bought the STX to use primarily with DT 880's 250 ohm but I'm getting the curious about some of the portable closed cans out there (most are pretty low impedance) and I'd like to be able to power them at home off the STX without bass getting out of control.


----------



## WiR3D

Quote: 





impulse said:


> Really interesting stuff, I'm surprised the thread hasn't garnered more posts... I have an STX too and I'm curious to try my hand at a similar adapter in order to improve it's performance with some of my other headphones. I bought the STX to use primarily with DT 880's 250 ohm but I'm getting the curious about some of the portable closed cans out there (most are pretty low impedance) and I'd like to be able to power them at home off the STX without bass getting out of control.


 
  its a fair amount of effort getting the parts and putting it together.
   
  reminds me I should update the first page, do some calculations first and notify others that if they want a bigger they must modify the serial resisters, not the parallel ones - or something like that.
   
  You just want to minimize the power going down the negative rail. - at 100% on max gain and too much power on the negative rail it could fry your card. combined with other factors thats what I did.


----------



## ertai

Sometimes I run a particular setup like this: USB DAC lineout >> amp (with bass boost) >> headphone (32Ohm). I am satisfied with the sound I get but the lowest volume is still very loud and not really good for long term listening.
   
  I did some research and figured an impedance adapter would help me.
   
  My question is: will adding an impedance adapter change the sound signature?


----------



## WiR3D

Quote: 





ertai said:


> Sometimes I run a particular setup like this: USB DAC lineout >> amp (with bass boost) >> headphone (32Ohm). I am satisfied with the sound I get but the lowest volume is still very loud and not really good for long term listening.
> 
> I did some research and figured an impedance adapter would help me.
> 
> My question is: will adding an impedance adapter change the sound signature?


 
  Depends on the headphone. 
   
  With Denons yes, and for the worse. With Grado not really, it may change the sound but not for the worse. 
   
  Its a trial and error. But it will drop the volume.
   
  or you can build a faux impedance decreasing adapter, that will chow a lot of power, so that will also work without the side effects, its just more work.
   
  EDIT: spelling


----------



## ertai

Thanks for the suggestion 
	

	
	
		
		

		
		
	


	



   
  For the purpose of solely reducing volume, do you think this item would be suitable?
  http://www.ebay.com.my/itm/281009593372?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
   
  I am using a different headphone than an Etymotic though


----------



## paaj

Sound may change, no way to tell other than trying (at $11 what's to lose?), but it'll definitely lower volume. Read the previous answer again, it still applies to your question. Except that you probably need to exchange fax with faux. It's mentioned in the topic start 
   
  I got one like those (well, the other one in the start post as I thought it looked nicer) at 120Ω and the volume really is significantly lower.


----------



## manveru

Quote: 





ertai said:


> Thanks for the suggestion
> 
> 
> 
> ...


 
   
  I don't recommend the adapters made by "wemakeamp." They had bad build quality, sometimes the channels were imbalanced, there was static, or the sound collapsed into mono. Look for the ones made by the eBay seller "awwan." They are more expensive, but I never had any issues like that with them.
   
  It doesn't matter, Etymotic or not.


----------



## ertai

Thank you for your advise 
	

	
	
		
		

		
		
	


	



   
  Quote: 





manveru said:


> I don't recommend the adapters made by "wemakeamp." They had bad build quality, sometimes the channels were imbalanced, there was static, or the sound collapsed into mono. Look for the ones made by the eBay seller "awwan." They are more expensive, but I never had any issues like that with them.
> 
> It doesn't matter, Etymotic or not.


----------



## WiR3D

Quote: 





paaj said:


> Sound may change, no way to tell other than trying (at $11 what's to lose?), but it'll definitely lower volume. Read the previous answer again, it still applies to your question. Except that you probably need to exchange fax with faux. It's mentioned in the topic start
> 
> I got one like those (well, the other one in the start post as I thought it looked nicer) at 120Ω and the volume really is significantly lower.


 
  facepalm... yes - my dumb spelling.
   
  The faux adapter will avoid the impedance mismatch, and drop the volume.


----------



## AnAnalogSpirit

Quote: 





manveru said:


> I don't recommend the adapters made by "wemakeamp." They had bad build quality, sometimes the channels were imbalanced, there was static, or the sound collapsed into mono. Look for the ones made by the eBay seller "awwan." They are more expensive, but I never had any issues like that with them.
> 
> It doesn't matter, Etymotic or not.


 
  I can also vouch for the adapters made by "awwan", everything I've bought from that seller has been above-board and high-quality, with no issues.


----------



## craigyhay

I have an xonar stx on order and have creative aurvana live 32ohm headphones and I dont have the skill to make one of the faux impedance adapters, I wondered if adding a splitter and attaching an extra set of headphones would deal/help with the impedance problem? or would I just be making things worse and adding impedance to the stx output from the headphones perspective.
   
  sorry in advance for my noob ness lol


----------



## gikigill

Any suggestions on how to reduce the output impedance on the iBasso PB2. What adapter would I need?


----------



## DrGroove

Bumping this for a question.
  
 I use low impedance (26 Ohm) IEMs with Focusrite 2i4 (output impedance 12 Ohm) and I'm looking to increase this damping factor without buying a new amp. I read the whole thread and I'm still not clear if these impedance adapters effectively increase damping factor or not?


----------



## zalbard

Hi all,
  
 thanks for the list. My laptop comes with a built-in amp (no, seriously...), and it is unusable with pretty much all IEMs I own due to constant hissing noise.
  
 I am looking to reduce it using an impedance adapter. My IEMs are 32 Ohm, I tried 250 Ohm headphones and the noise is almost gone.
 So I would like to purchase a 100+ Ohm adapter (mini-to-mini).
  
 One requirement, though. It has to be either cabled, or right angled. Ultimate Ears one would work (from the table), but I cannot seem to be able to find it for sale anywhere... But other options are also welcome.
  
 Would anyone care to help? It would be much appreciated, thanks.


----------



## sanyourse

it will take sum time to find out, if there is a demand for it, I will do it.


----------



## CantScareMe

Just bought a 1/8 to 1/4 impedance adapter. Need less gain on an amp.
  
 Should be good. 
  
 Thanks for this thread btw WiR3D.


----------



## roflaly

cantscareme said:


> Just bought a 1/8 to 1/4 impedance adapter. Need less gain on an amp.
> 
> Should be good.
> 
> Thanks for this thread btw WiR3D.


 
 Any update on how that worked out? Might be looking to get one to use with the 598 and Vali.


----------



## CantScareMe

Sure mate.
  
 It works perfectly fine, but not too great for sound quality. It acts as if to increase the amps output resistance and makes headphones seem darker / muddier / more closed in. This is especially true of the lower impedance ones i've got and say with a T1 it's much less pronounced. 
  
 None of this is surprising at all btw as this is how it's meant to work. Basically it does it's job perfectly!
  
 It's quite big though (physically big I mean). I'll post a picture when I get home so you can see.


----------



## dukeReinhardt

Derp, bad reading comprehension.


----------



## twister6

Can anybody please let me know if this UE airline signal attenuation adapter supplied with UE900 is actually a regular impedance adapter?
  

  
 Here is why I'm asking.  I have Hidizs AP100 DAP with a high level of HO (2.2Vrms).  When paired up with ZA Carbo Doppio (12 ohm and a whooping 113 dB/mW sensitivity) it produces a  high level of white noise when idle (not even playing music).  I guess it's expected with high level signal output and high sensitivity IEMs.  I just used my UE900 airline adapter, which supposed to attenuate the signal, and BOOM! problem solved.  I assume it's nothing but impedance adapter that works like a voltage divider to cut down output level of the source.  So, I want to confirm if you guys know the spec of it?  I want to find a more elegant solution with a slim 3.5mm adapter and trying to figure out what to look for; UE above is a rather big dongle.  I remember at the beginning of the thread, it was mentioned about UE 100ohm adapter.  Is that the one?  Any suggestions or links are welcome!


----------



## ClieOS

As far as I know, the UE adapter is indeed just a 100ohm adapter and nothing more (*not a voltage divider). So basically you just added 100ohm more to the AP100's output impedance.


----------



## twister6

clieos said:


> As far as I know, the UE adapter is indeed just a 100ohm adapter and nothing more (*not a voltage divider). So basically you just added 100ohm more to the AP100's output impedance.


 
  
 Thank you ClieOS!!!
  
 I wonder if they would have something similar to this: http://www.ebay.com/itm/Impedance-Adapter-Plug-75-ohms-3-5mm-to-1-4-inch-plug-/251464612918?pt=US_Cables_Snakes_Interconnects&hash=item3a8c757c36 but with 3.5mm connector.  I think 75ohm might work as good as 100ohm, just need 3.5mm plug...
  
 ... nevermind, found Ety's adapter where you can select different impedance option: http://www.ebay.com/itm/Etymotic-ER4P-to-ER4S-3-5MM-plug-resistor-adaptor-/281276949691?pt=US_MP3_Player_Cables_Adapters&hash=item417d69a4bb


----------



## zagtastic

i recently discovered and read this entire thread with great interest, however i still have a question:
  
 is there still no way to obtain a (faux) impedance decreasing adapter commercially?  i have a CL theorem 720 dac and really want to use it with DN-1000 phones, but the noise floor is distracting.  i would very much love a portable, <$100 solution that allowed me to pair these without affecting SQ.  unfortunately i'm a computer guy but not an electronics guy and don't think the DIY option will work for me.  thanks much in advance.
  
 basically, i was hoping that in the last 6 years a reputable company would have made the same thing as WiR3D, as i could really use one


----------



## twister6

zagtastic said:


> i recently discovered and read this entire thread with great interest, however i still have a question:
> 
> is there still no way to obtain a (faux) impedance decreasing adapter commercially?  i have a CL theorem 720 dac and really want to use it with DN-1000 phones, but the noise floor is distracting.  i would very much love a portable, <$100 solution that allowed me to pair these without affecting SQ.  unfortunately i'm a computer guy but not an electronics guy and don't think the DIY option will work for me.  thanks much in advance.


 

 Why not get something like this for $14, in either 75ohm or 150ohm flavor? http://penonaudio.com/3.5mm-Inpedance-Plug
  
 Noise floor comes from high sensitivity headphones driven by high level power source.  My temp solution of driving Zero Audio Doppios from AP100 DAP is with 100ohm UE adapter (came bundled with UE900 headphones), but I'm waiting to receive these impedance adapter from penonaudio now since it's a cleaner solution.
  
 Is that what you are looking for?


----------



## zagtastic

twister6 said:


> Why not get something like this for $14, in either 75ohm or 150ohm flavor? http://penonaudio.com/3.5mm-Inpedance-Plug
> 
> Noise floor comes from high sensitivity headphones driven by high level power source.  My temp solution of driving Zero Audio Doppios from AP100 DAP is with 100ohm UE adapter (came bundled with UE900 headphones), but I'm waiting to receive these impedance adapter from penonaudio now since it's a cleaner solution.
> 
> Is that what you are looking for?


 
  
 appreciate it twister, but based on what i have read here and other places (including: http://www.innerfidelity.com/content/meridian-explorer-case-study-effects-output-impedance), the effect of such an adapter would be expected to be a reduction in sound quality.  unless i'm missing something, that adapter will raise the apparent impedance of the output as seen by the headphones which will result in at least some amount of coloration and muddying of the sound as well as a decrease in the damping effect.  if that's the case, i may as well plug the dunus directly into my smartphone (primary DAP) and bypass the external dac/amp.  please let me know if i'm wrong, but assuming that the impedance plug is an impedance increasing adapter rather than a "(faux) impedance decreasing adapter", that is the expected result.


----------



## twister6

zagtastic said:


> appreciate it twister, but based on what i have read here and other places (including: http://www.innerfidelity.com/content/meridian-explorer-case-study-effects-output-impedance), the effect of such an adapter would be expected to be a reduction in sound quality.  unless i'm missing something, that adapter will raise the apparent impedance of the output as seen by the headphones which will result in at least some amount of coloration and muddying of the sound as well as a decrease in the damping effect.  if that's the case, i may as well plug the dunus directly into my smartphone (primary DAP) and bypass the external dac/amp.  please let me know if i'm wrong, but assuming that the impedance plug is an impedance increasing adapter rather than a "(faux) impedance decreasing adapter", that is the expected result.


 
  
 True, it's not a transparent solution.  But I haven't heard any coloration changes, at least with a pair of IEMs I tested (ZA Doppio).  Of course, it all depends on the headphone.  At the same time, when I tried my "reference" pair of ZA Tenores that work fine as is due to their lower sensitivity, and compared with and without 100ohm adapter, I noticed a reduction in airy details.  Sorry, I'm not aware of any other solution, perhaps someone else can chime in?


----------



## mindbomb

nvm


----------



## Zenbun

Anyone know if there are any impedance plugs that have just 10-20 ohm?


----------



## ozkan

zenbun said:


> Anyone know if there are any impedance plugs that have just 10-20 ohm?


 
  
 You can choose between 15 and 620 ohms from this seller. 
  
 http://www.ebay.com/itm/ETYMOTIC-ER4P-TO-ER4S-RESISTOR-ADAPTOR-3-5MM-PLUG/291329605627?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D30542%26meid%3Ded9fbaa7793c46b894b171f2cf8893e5%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D281657676624&rt=nc


----------



## USHI

Does anyone know where I can get the UERM impedance adapter ( not the airline attenuator ) or have one and dont use it?


----------



## Luckbad

Is there any consensus about which of these are particularly good? I'd like to get one so my IEMs pair better with a couple of my amps. Thanks!


----------



## DrKC

I may be missing something here as I have not read the whole thread.  What I can gather is that those with hyper-sensitive iems are looking for a form of attenuation to lower the noise/hiss from an amp.  This seems to have become balled up with output impedance effects on frequency/amplitudes.
 Let's just start with an ideal amp that has zero ohms output impedance.  We'll plug our headphones in.  Headphones have an impedance not just a resistance.  This impedance will vary with frequency.  As long as our amp stays at zero ohms output Z, any variations of amplitude due to impedance changes will be strictly related to the headphones - not the amp.
 If we add pure resistance - no capacitance or inductance - in series with our headphones, the amp will not change it's behavior or alter the sound quality.  This resistance (formulas for impedance or Z are easily found on the net) will present a higher Z load to the amp and reduce the output current.  The overall variation in impedance will be somewhat swamped by the pure resistance.  If the resistance is high enough, the varying impedance of the phones will appear to diminish over frequency.
 To make a long story short, adding only resistance in series with your headphones will result in some attenuation and a change in the phones apparent impedance.  It doesn't affect the sound quality of the amp.  If the amp has a significant output impedance, this is another kettle of fish and reflects the issue discussed at Innerfidelity. 
 The cables mentioned most likely have only resistors in them.  They are most likely in series with the signal lines or there is a single resistor in the ground line.  These will not lower the sound quality like an amp with high output impedance.


----------



## paaj

I must say I liked the previous theory better 
How else to use a headphone like the Q701, which is supposedly designed for 120 Ohms output, properly?


----------



## Luckbad

I received the 75 Ohm impedance resistor adapter from AW Audio Accessory (awwan) today. It's very high quality and lets me notch up the volume several degrees, gettnig my 16 Ohm IEMs out of the imbalanced volume land they resided in with my Vorzuge VorzAMP Duo (at least for all day listening, they were just a little too loud. Now they're not). I'm hearing no reduction in sound quality, but this weekend I'll test frequency response and all the rest with it.


----------



## landroni

luckbad said:


> I received the 75 Ohm impedance resistor adapter from AW Audio Accessory (awwan) today. It's very high quality and lets me notch up the volume several degrees, gettnig my 16 Ohm IEMs out of the imbalanced volume land they resided in with my Vorzuge VorzAMP Duo (at least for all day listening, they were just a little too loud. Now they're not). I'm hearing no reduction in sound quality, but this weekend I'll test frequency response and all the rest with it.


 

 Did you complete the tests? Still happy with the sound quality?


----------



## Luckbad

landroni said:


> Did you complete the tests? Still happy with the sound quality?


 
  
 I totally haven't yet. I keep forgetting the adapter at work every weekend. I've been using it for a couple weeks and I'm happy with it.
  
 I'm also going to eventually build one of these after I learn to solder and such: https://diyaudioheaven.wordpress.com/headphones/headphone-attenuation-adapter/
  
 I'll try to remember to bring the thing back with me soon.


----------



## landroni

@WiR3D


  


  


  
 If you're still trying to keep the original list up-to-date, there is another cable on ebay and penon:
 3.5 mm Male to Female HIFI Audiophile Nvwa Copper-Silver 75 Ohm Impedance Cable


  
 Produced by Palic ( Pailiccs ), but I can't figure if it's genuine brand or something generic. Anyways, ~$55.00:

  
 http://penonaudio.com/3.5%20mm-Male-to-Female%20

  
 http://www.ebay.com/itm/3-5-mm-Male-to-Female-HIFI-Audiophile-Nvwa-Copper-Silver-75-Ohm-Impedance-Cable-/121106916348

  
 
  
 Another one is more generic, it seems, at 75 and 150 Ohm for ~10$:

  
 http://penonaudio.com/3.5mm-Inpedance-Plug

  
 http://www.ebay.com/itm/3-5mm-to-3-5mm-Impedance-Adapter-Plug-For-Hi-Fi-Audio-player-AMP-DAC-Earphone-/380932180092?var=&hash=item58b153c87c


----------



## landroni

ozkan said:


> You can choose between 15 and 620 ohms from this seller.
> 
> 
> http://www.ebay.com/itm/ETYMOTIC-ER4P-TO-ER4S-RESISTOR-ADAPTOR-3-5MM-PLUG/291329605627?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D30542%26meid%3Ded9fbaa7793c46b894b171f2cf8893e5%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D281657676624&rt=nc


 

 Is there an _optimum_ impedance level to choose for such adapters (for use with IEMs)? Should one take the (what appears to be default) 75 Ohm; or should it be the 150 Ohm; or maybe something like 36 Ohm is preferable?
  
 I'm trying to understand what impedance level should one target to reduce noise level but avoid changes in sound quality/signature...


----------



## bbb321

hey guys im trying to plug apple earpods into a headphone amp with one of those standard 3.55mm to 1/4 inch adapters and getting some noise/hiss. Do I need an impedance adapter to fix this? also anyone notice with apple phones into an adapter have phase issue when plugged in all the way? i need to play with it taking it slightly out from all the way to find the right spot.. thanks


----------



## landroni

luckbad said:


> I received the 75 Ohm impedance resistor adapter from AW Audio Accessory (awwan) today. It's very high quality and lets me notch up the volume several degrees, gettnig my 16 Ohm IEMs out of the imbalanced volume land they resided in with my Vorzuge VorzAMP Duo (at least for all day listening, they were just a little too loud. Now they're not). I'm hearing no reduction in sound quality, but this weekend I'll test frequency response and all the rest with it.


 

 I got the same adapter from awwan, and while I was initially happy with the build quality (it didn't seem to affect the sound signature of my FiiO EX1), it's clearly (partly) a hand-made item. After a week or so of listening I had issues with the left channel, whereas sometimes I hear only from the right channel and I need to turn the headphones connection within the adapter to make the contact work and the left channel work again. It's frustrating. I think it makes more sense to go for a ~50$ priced item from the start, to get a more a standardized build quality.
  
 I'll probably get an APureSound impedance adapter next (45$):
 http://apuresound.com/ra.html
  
 Did anyone had experience with APureSound adapters?


----------



## landroni

bbb321 said:


> hey guys im trying to plug apple earpods into a headphone amp with one of those standard 3.55mm to 1/4 inch adapters and getting some noise/hiss. Do I need an impedance adapter to fix this? also anyone notice with apple phones into an adapter have phase issue when plugged in all the way? i need to play with it taking it slightly out from all the way to find the right spot.. thanks


 

 Either an impedance adapter, or a headphone amp designed for IEMs like FiiO E12A. But if you're bothering with a headphone amp, then perhaps most appropriate would be an upgrade in headphones, like e.g. the entry level but excellent value for price FiiO EX1.


----------



## Lunatique

I just bought this from ebay, and I think I got the wrong one: http://www.ebay.com/itm/271320560060
  
 What I'm trying to do, is to DECREASE the impedance of my sources, so that my very sensitive low-impedance IEMs (Angie, RE600S--both are 16 Ohm) will sound correct. Right now,Angie has significant lower volume in the 4KHz region and sounds hollow when plugged into my computers or headphone/speaker controller, but sounds much more neutral when plugged into my Galaxy Note 3. 
  
 I bought that adapter assuming it'll increase the impedance of the IEM, but I think it's actually the opposite, because when I used it on my Note 3, it had the same problem with the 4KHz region. 
  
 So I guess this means I'm SOOL and should just use amps with very low impedance instead (<1 Ohm)?


----------



## polecrab

Does anyone know whether it matters in which direction you use one of these adapters (e.g., http://www.ebay.com/itm/ETYMOTIC-ER4P-TO-ER4S-RESISTOR-ADAPTOR-3-5MM-PLUG-/291329605627?)? Let's say I wanted to use this adapter with a headphone that had a remote mic cable for use with iPhones. If I plugged this adapter into the iPhone, the mic wouldn't work. However, if the headphone had a 3.5mm jack on the cup for a removable cable, then I could plug the impedance adapter into the headphone and then plug the cable into the adapter jack. This would allow the mic to work. However, the adapter would be in reverse direction from how it was intended to be used. I'm wondering if reversing the direction would make a difference. My goal is to reduce the sensitivity of the headphones so I can have finer control of my volume in the lower ranges (I never have my volume control past 12 o clock, even when driving my 300-ohm HD600 directly with an iPhone).


----------



## ozkan

Finally I got my 75 ohm adapter from Bocur Audio which sounds amazing compared to the original Etymotic 75 ohm cable. 

http://m.ebay.com/itm/BOCUR-AUDIO-PURE-COPPER-99-99-75OHM-ADAPTER-CABLE-FREE-SHIPPING-TO-WORLDWIDE-/331798876094?nav=SEARCH


----------



## mdiogofs

I want to buy an impedance adaptor but don't know how many ohm should I choose...Let's say that, in a DAP, an IEM that has 16 Ohm hiss but other IEM at 32 ohm don't hiss. Should a 20 ohm adaptor be enough or I need to buy something higher?


----------



## ClieOS

mdiogofs said:


> I want to buy an impedance adaptor but don't know how many ohm should I choose...Let's say that, in a DAP, an IEM that has 16 Ohm hiss but other IEM at 32 ohm don't hiss. Should a 20 ohm adaptor be enough or I need to buy something higher?


 
  
 Hiss or not is a result between how hissy the individual source is and how hiss prone the individual IEM is, therefore there isn't one universal answer to say which one small impedance number will work for every source and IEM combo out there. If you are not sure, always go a but higher than what you think you need. Otherwise, it is pretty much a trial and error process for most of us.


----------



## mdiogofs

Well, I bought a 20 Ohm impedance adapter to test things out. Let's see how it works, the hiss is not very bad...8 dollar so...Let's see the impact on things.


----------



## ph0n6

Anyone tried out the annentuator from this DIY site: https://diyaudioheaven.wordpress.com/headphones/headphone-attenuation-adapter/
 It is supposed to decrease volume (and hopefully hiss as it does block more currents?) and kept the output impedance that the headphone "sees" low (lower than 1ohm), thus minimizing any changes to the sounds. I tried the 75ohm adapter from ebay but it makes the sounds shouty and hollow, there are no more hiss though.


----------



## mdiogofs

Well, I bought a 20 Ohm impedance adapter to see if the impact on sound is minimum.


----------



## mdiogofs

And it works! Using iBasso DX80 and Ostry KC06, the hiss was reduced considerably. Didn't felt impact in sound. Need to get the volume a bit louder. So, just a 20 Ohms impedance adaptor really makes the difference.


----------



## JayNYC

reviving this thread....  if I have a headphone amp with a 5 ohm output impedance, but I would like it to have a 4 ohm output impedance so it works with 32 ohm headphones (8x), which on-the-market product would I buy?
 the headphone amp has a 1/4" female jack, and the headphones have a 3.5mm male plug.
  
 thanks


----------



## Lunatique

jaynyc said:


> reviving this thread....  if I have a headphone amp with a 5 ohm output impedance, but I would like it to have a 4 ohm output impedance so it works with 32 ohm headphones (8x), which on-the-market product would I buy?
> the headphone amp has a 1/4" female jack, and the headphones have a 3.5mm male plug.
> 
> thanks


 
 Based on my previous experience buying the wrong impedance adapter (my previous post is still on this same page, I think), I don't think there are any available commercial impedance "stepping down" adapters available.


----------



## yawg

Hi,
  
 I read the whole thread but am no technician and sometimes I couldn't follow the math ...
  
 Anyway, my problem is not a big one as my BossHifi B8 over-ear HPs (impedance 16 Ohms, sensitivity 106 dB) sound very good directly from the HP out of my Nokia N8 phone. But I also bought a refurb FiiO E7 for its built-in DAC and extra power. With some low-volume recordings (e.g. old digitized LPs) I have to open up the phone's volume all the way which results in a somewhat wooly bass. Hiss is no problem, all the hiss comes from the tapes of the recordings.
  
 When I connect my FiiO as DAC via micro USB I can listen very loud but the dynamics are notably less, dynamic recordings sound compressed that way. The output impedance of the E7 is only 0.13 Ohm. FiiO states it can drive HPs from 16 to 300 Ohms but the 16 Ohms of my B8 are borderline.
  
 Which solution would be the best for me listening through the FiiO? A 75 Ohm adapter plug? Or would a metal film resistor (which value?) in parallel with the HP be enough? The FiiO has loads of headroom for the B8 connected as DAC/amp. I'm not sure yet which DAC I prefer but it seems the Wolfson of the FiiO is slightly more revealing.
  
 These are my HPs, I highly recommend them if you like over-ears:
  

  
  
 Thanks for your input.


----------



## LogicalDisconnect

I'm looking at some IEMs (Campfire Andromeda) that are very sensitive and apparently sound best with a source having around 3 to 4 ohms of output impedance. If I have an amp with near zero output impedance, is there an easy way to increase the 'effective' output impedance by just a few ohms?


----------



## ExpatinJapan

The Andromeda suits a dap with 1ohm or less OI. So youre good


----------



## LogicalDisconnect

Apparently they sound significantly darker / bassier with lower output impedance sources though? I prefer a brighter signature (my desktop headphones have been HD800 and HD800S) so I'm not sure that's for me but the Andromeda seems to tick every other box. The amp / DAC I'm looking at is the Mojo which apparently also hisses a bit with the Andromeda but again seems to otherwise fit the bill. That's why I'm looking at ways to increase effective output impedance.


----------



## ExpatinJapan

If you prefer a brighter earphone then buy one.imho.

Dont use adapters or EQ, find a earphone with a sound signature that you like.

I dont find the andromeda bassy or dark. (See my review) and no hiss with the CEntrance DACportable I just reviewed.

Regards
Expat


----------



## ph0n6

Btw the Ifi Iematch adapter is released. Maybe I will get one and try it out.


----------



## Thenewguy007

Any device I can buy to have my amp give out more impedance?

My amp is like 0 Ohms, but my headphones are all high impedance.


----------



## Ike1985

Any suggestions on a 20-30 ohm impedance adapter for my 64 audio ADEL A12's ro pair with Chord Mojo? A12's sound better with higher output impedance.


----------



## PeterPangea

Penon Audio has a good one for ~$10.


----------



## Jimster480

To revive this thread again, I have Amps that have 10 and 30 ohm output impedances.
I want to present a 240-300 ohm load to the 30 ohm output and a 100 ohm load to the 10ohm output in order to get the maximum out of the amp and have a "perceived" output impedance of 0-2 on my headphones (since some are 16-24 ohm).

Are there any commercial products for this? I see most of them are for lowering volume (increasing input impedance of headphones / increasing output impedance of amp).
I want to present the proper load for the correct performance and then step it down for my headphones. 

I have the UE buffer jack and it certainly makes things quieter, but its really hard to tell if it does anything to details.
Honestly it doesn't sound much better with this plugged in, so I'm not sure what kind of adapter it is.


----------



## Snowball0906

Is there any device that suits AR-M2 to pair up with sensitive iems?


----------



## dhruvmeena96

Is 75ohm adapter going to work with my smartphone(using KZ es4) or should I go for 20ohm adapter from niceHCK.
My phone is Lenovo z2 plus


----------



## paulindss

So, there aren't any adapter in the market that reduces the output impedance of a AMP ?

If i use this: 
75 150 200 Ohm Impedance Resistance 3.5mm Male To Female Adapter Conductor For JH24 HD25 ER4 Headphone Earphone Cable LN005495
https://s.click.aliexpress.com/e/cO4jjrSp

They will low the output impedance or increase ? Or They will increase just the input impedance of the iem so i can use my iem in the amp?


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## paulindss

Lunatique said:


> I just bought this from ebay, and I think I got the wrong one: http://www.ebay.com/itm/271320560060
> 
> What I'm trying to do, is to DECREASE the impedance of my sources, so that my very sensitive low-impedance IEMs (Angie, RE600S--both are 16 Ohm) will sound correct. Right now,Angie has significant lower volume in the 4KHz region and sounds hollow when plugged into my computers or headphone/speaker controller, but sounds much more neutral when plugged into my Galaxy Note 3.
> 
> ...



If they work like these it means that they are pretty much useless then, who in the hell would want a OI of 75ohm ?


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## aspire5550

paulindss said:


> If they work like these it means that they are pretty much useless then, who in the hell would want a OI of 75ohm ?



I believe you might be interested in this. I am not sure if this actually works but according to the author, it reduces the Output impedence of any source to around 2-3 ohm. (yes, if your source have a OI of 0.1ohm , it will bring it up to 2-3ohm)

https://diyaudioheaven.wordpress.com/headphones/headphone-attenuation-adapter/


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## paulindss

aspire5550 said:


> I believe you might be interested in this. I am not sure if this actually works but according to the author, it reduces the Output impedence of any source to around 2-3 ohm. (yes, if your source have a OI of 0.1ohm , it will bring it up to 2-3ohm)
> 
> https://diyaudioheaven.wordpress.com/headphones/headphone-attenuation-adapter/



Hi friend, actually i just made these! 
In reality i paid for someone experienced do, and it all went well, the attenuation happens! But the difference in soundsignature from my a30 output and the attenuator is marginal, not at all like i imagined. But i searched for some graphics on difference in output and tonal balance on diy site and it is small most of the times. I reccomend doing  it because it turns able to put a lot of power in the iem from a small volume, incriesing dynamics, (i think) i can post pictures if anyone wish.

I think it works because a multimeter showed 35 constant input impedance on the male, juts like the tutorial says, and the male measured showed like 0.2 in the female out.  I think that means something.

I think of doing one with 1ohm output impedance and a p10 male (better finish), there is a scheme in the comment section for the 1ohm output.


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## DivergeUnify

paulindss said:


> Hi friend, actually i just made these!
> In reality i paid for someone experienced do, and it all went well, the attenuation happens! But the difference in soundsignature from my a30 output and the attenuator is marginal, not at all like i imagined. But i searched for some graphics on difference in output and tonal balance on diy site and it is small most of the times. I reccomend doing  it because it turns able to put a lot of power in the iem from a small volume, incriesing dynamics, (i think) i can post pictures if anyone wish.
> 
> I think it works because a multimeter showed 35 constant input impedance on the male, juts like the tutorial says, and the male measured showed like 0.2 in the female out.  I think that means something.
> ...


Any advice on where to find someone to make it?


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## paulindss

DivergeUnify said:


> Any advice on where to find someone to make it?



I found at a audio components store, where they sell conectors, resistors, PA equipment and etc. They reccomended me one of the workers, and he did it for me.


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## Arjey

Hi! Is this thread still active? I was just wondering, has anyone tried these?
https://s.click.aliexpress.com/e/YO49moIJh
https://s.click.aliexpress.com/e/DGvCoy6Qn
(Sorry if the links don't work, just try searching "impedance adapter" in AliExpress, sort by orders, and the first 2, DUNU and FAAEAL)
The thing is, my phone is a Xioami Mi A1, and it has a powerful amp, but it has a lot of static/noise when listening in low impedance/high sensitivity IEMs. If I plug in some 80 Ohm headphones, everything is great, but low is too noisy to even listen to. So, will this fix the problem? I also have an MP3 player, I don't know much about it's characteristics, it's diy, it has no noise even with low impedance, but it just doesn't sound right, especially BA(balanced armatures) only 100+Ohms. Will this fix the problem?


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## CopperFox

Arjey said:


> Hi! Is this thread still active? I was just wondering, has anyone tried these?
> https://s.click.aliexpress.com/e/YO49moIJh
> https://s.click.aliexpress.com/e/DGvCoy6Qn
> (Sorry if the links don't work, just try searching "impedance adapter" in AliExpress, sort by orders, and the first 2, DUNU and FAAEAL)
> The thing is, my phone is a Xioami Mi A1, and it has a powerful amp, but it has a lot of static/noise when listening in low impedance/high sensitivity IEMs. If I plug in some 80 Ohm headphones, everything is great, but low is too noisy to even listen to. So, will this fix the problem? I also have an MP3 player, I don't know much about it's characteristics, it's diy, it has no noise even with low impedance, but it just doesn't sound right, especially BA(balanced armatures) only 100+Ohms. Will this fix the problem?



I have the Faaeal impedance adapters, both 80Ω and 220Ω. Have been using them (the latter more) to get more power and less noise out of an OTL tube amp as tube amps generally put out higher and cleaner power to a higher impendance load. They've been working great so far. My headphones mostly sound better with these than with any of my solid state amps. 

Ordered the Dunu adapters to try them out as well. I'd want to get a 300Ω adapter as well, but haven't found any yet.


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## davidtriune

I'm looking to increase the damping factor for my headphones. So basically impedance increasing adapters will do nothing to raise the damping factor? the "faux impedance reducing adapters" will?


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