[MattTCG]

I bought this LME49860NA x3 for $10 bucks ebay. Sounded very similar...not quite as good as stock. Disappointed. I was hoping for some noticeable difference really. It was almost exactly the same. Not sure I did something wrong.

 

[PurpleAngel]

Quote:

I bought this LME49860NA x3 for $10 bucks eBay. Sounded very similar...not quite as good as stock. Disappointed. I was hoping for some noticeable difference really. It was almost exactly the same. Not sure I did something wrong.

 
I doubt you did anything wrong.
Try using them for a week, then switch back. Then see what your ears tell you.
 
 

 

[WiR3D]

Quote:

I bought this LME49860NA x3 for $10 bucks ebay. Sounded very similar...not quite as good as stock. Disappointed. I was hoping for some noticeable difference really. It was almost exactly the same. Not sure I did something wrong.

 
Also what headphones are you using them with, Amps aswell?
 
 

 

[WiR3D]

I created a list of impedance adapters for non-DIYers trying to use low impedance phones such as the D2k.
I havent quite figured what will be good for the D2k though...
 
Judging but what i read the 600ohm beyers perform better then the 250ohm ones, and according to the article by NwAvGuy, the rule is the minimum EDIT: required (i.e maximum allowed) output impedance should be 1/8th of the headphones impedance, and the desired is 1/25th.
 
By that logic with the D2k you want 250ohm of resistance. So im trying to figure if i should just go for 600ohm, or what?!

 

[stv014]

Quote:

Originally Posted by WiR3D /img/forum/go_quote.gif
 
Judging but what i read the 600ohm beyers perform better then the 250ohm ones, and according to the article by NwAvGuy, the rule is the minimum output impedance should be 1/8th of the headphones impedance, and the desires is 1/25th.

 
Actually, it is the maximum that should be 1/8th, i.e. for a 32 Ohm headphone, 4 Ohm or lower. However, it is possible that the high impedance (250 and 600 Ohm, but not the 32 and 80 Ohm models) Beyerdynamic headphones are actually optimized for high impedance (100 or 120 Ohm) sources, especially since their own A1 amplifier has an output impedance of 100 Ohm. This would also explain why the 250 Ohm versions of both the DTxx0 series and the T70 have a slightly "thinner" sound than the others from the same low impedance source.
 

 

[WiR3D]

Quote:

 
Actually, it is the maximum that should be 1/8th, i.e. for a 32 Ohm headphone, 4 Ohm or lower. However, it is possible that the high impedance (250 and 600 Ohm, but not the 32 and 80 Ohm models) Beyerdynamic headphones are actually optimized for high impedance (100 or 120 Ohm) sources, especially since their own A1 amplifier has an output impedance of 100 Ohm. This would also explain why the 250 Ohm versions of both the DTxx0 series and the T70 have a slightly "thinner" sound than the others from the same low impedance source.
 

I phrased it horribly, but yeah, thats what i meant. wow 100ohm? Thats horrible, but if it works, it works i guess.
 
Still doesn't answer my question tho, should i go for a 200ohm or 600ohm impedance adapter? And will it have any negative side effects on headphones or soundcard?
 
Heres the logic, low impedance cans generally use more current(correct?) and high impedance more voltage(correct?) i know the STX is capable of high voltage, as someone stated previously, so I am less worried about that, but more about my headphones.
If i increase the resistance will it feed more voltage to my headphones? Or will they just drop volume until you feed them the current they require?

 

[stv014]

If the adapter consists of a simple serial resistor per channel, then it is basically just added to the output impedance. For example, using a 120 Ohm adapter will result in 130 Ohm total output impedance. This reduces the voltage on the headphones (making them quieter, but also less noisy), and reduces the damping factor as well.
If you want to decrease the impedance for the Denons, it is more tricky, and needs both a serial and a parallel resistor per channel. This does waste a lot of power, though. For example, a 20 Ohm serial and 4.7 Ohm parallel resistor would reduce the effective output impedance to about 4 Ohm, but increase the voltage requirement to a level comparable to that of the 600 Ohm DT880, while the card still has to drive a similarly low impedance load as the D2000 itself.
 

 

[WiR3D]

Quote:

If the adapter consists of a simple serial resistor per channel, then it is basically just added to the output impedance. For example, using a 120 Ohm adapter will result in 130 Ohm total output impedance. This reduces the voltage on the headphones (making them quieter, but also less noisy), and reduces the damping factor as well.
If you want to decrease the impedance for the Denons, it is more tricky, and needs both a serial and a parallel resistor per channel. This does waste a lot of power, though. For example, a 20 Ohm serial and 4.7 Ohm parallel resistor would reduce the effective output impedance to about 4 Ohm, but increase the voltage requirement to a level comparable to that of the 600 Ohm DT880, while the card still has to drive a similarly low impedance load as the D2000 itself.

Could you elaborate? I find this interesting, I did previously come across a statement where it was said that using an impedance adapter adds to the output impedance of the amp and not to the total impedance of the headphones, but the number of statements for the latter outnumbered the former.
 
I would like very much to either increase the resistance of my headphones which now doesn't seem possible, or decrease the output resistance of the soundcard, without losing quality.

 

[stv014]

Quote:

 
Could you elaborate? I find this interesting, I did previously come across a statement where it was said that using an impedance adapter adds to the output impedance of the amp and not to the total impedance of the headphones, but the number of statements for the latter outnumbered the former.

You cannot really increase the impedance of the headphones for the purpose of improving electrical damping, other than by getting a different model (or higher impedance drivers, if possible). Regardless of the above interpretations, adding serial resistance anywhere (in the amplifier, the cable, or the voice coil) while keeping the headphone otherwise unchanged reduces the electrical damping effect. For lower resistance/more damping you need one of the following:
  - a better amplifier with low output impedance
  - a transformer (not practical, and can affect the sound quality)
  - the above mentioned type of adapter with parallel resistors; this is not ideal either, as the impedance still remains relatively high, and it wastes power

 

[WiR3D]

Quote:

You cannot really increase the impedance of the headphones for the purpose of improving electrical damping, other than by getting a different model (or higher impedance drivers, if possible). Regardless of the above interpretations, adding serial resistance anywhere (in the amplifier, the cable, or the voice coil) while keeping the headphone otherwise unchanged reduces the electrical damping effect. For lower resistance/more damping you need one of the following:
  - a better amplifier with low output impedance
  - a transformer (not practical, and can affect the sound quality)
  - the above mentioned type of adapter with parallel resistors; this is not ideal either, as the impedance still remains relatively high, and it wastes power

 
Thank you for the explanation, well it seems the third option is the most practical.
I dont really care for wasting power, ideally I would want the output impedance at 1 ohm, but anything 4 ohm and under will be fine for this experiment.
The question of power is, how much can I waste before I have too little volume.
 
Also why those specific impedances on the resistors?
 
 

 

[stv014]

Quote:

Originally Posted by WiR3D /img/forum/go_quote.gif
 
Also why those specific ratings?

 
With these resistors, the overall output impedance is reduced to about 4 Ohm, the load impedance to the amplifier remains similar to the original impedance of the headphones (~24 Ohm), and the maximum SPL is still above 110 dB. Although the TPA6120 will have to output more current for the same volume, so it will run hotter, and the distortion may also be increased slightly. On the other hand, if there was any audible noise, it should be fixed/improved. The 20 Ohm resistor could also be replaced with a 24 Ohm one, for slightly higher load impedance.
 

 

[WiR3D]

Quote:

With these resistors, the overall output impedance is reduced to about 4 Ohm, the load impedance to the amplifier remains similar to the original impedance of the headphones (~24 Ohm), and the maximum SPL is still above 110 dB. Although the TPA6120 will have to output more current for the same volume, so it will run hotter, and the distortion may also be increased slightly. On the other hand, if there was any audible noise, it should be fixed/improved. The 20 Ohm resistor could also be replaced with a 24 Ohm one, for slightly higher load impedance.

Thanks for all the help, i paraphrased all the information, and created a thread to distinguish the differences, and explain impedance adapters (increasing and decreasing)

Impedance Adapters/Cables | Explained & Listed

 

 

[PurpleAngel]

My ten AD797BR (20 chips) adapters (dual SOIC to DIP-8) arrived from China.
Installed three into my Essence STX, I'm sure there is only about 1mm between the top of the adapters and the Essence STXs shield cover.
I'm sure they are not fake AD797BRs, the sound at least matches my LME49860NAs.
(I think Heavy Metal's Takn' a Ride sounds a little better/clearer then normal).
I have several different model headphones I'm going to be testing (movies and music) the AD797BRs with.

 

[WiR3D]

Quote:

My ten AD797BR (20 chips) adapters (dual SOIC to DIP-8) arrived from China.
Installed three into my Essence STX, I'm sure there is only about 1mm between the top of the adapters and the Essence STXs shield cover.
I'm sure they are not fake AD797BRs, the sound at least matches my LME49860NAs.
(I think Heavy Metal's Takn' a Ride sounds a little better/clearer then normal).
I have several different model headphones I'm going to be testing (movies and music) the AD797BRs with.

Thats Alot of chips, which would you say have the most balanced response, with a big (note not k70x giant) soundstage, and with butter smooth highs?
 

 

[PurpleAngel]

Quote:

Thats Alot of chips, which would you say have the most balanced response, with a big (note not k70x giant) sound stage, and with butter smooth highs?

Listening to Another Brick in the Wall (FLAC), using the AKG K242HDs, does sound nice, the AKG K242HD have a nice mid range.
Will do more testing in the morning, when I'm more awake.