[thefallenangelx]

Hi,
i have made a CMOY with a ad8620 on a diy browndog adapter + bypass caps+ power cap 470uf.
The gain is 5.7...and i have a 70ohm impedence headphone (sony mdr xd200)...should i upgrade to 11 as gain? there will be any improvement in sound quality?
How to calculate gain considering the headphone impedance ure using?
thanks to everyone

 

[TzeYang]

no, with lower impedance phones it's best you stick to low gain. Heck i even use a gain of 2-3 for my HD650.

EDIT: Misunderstood your 2nd question.

The impedance does not matter. It's a matter of headphone sensitivity and your personal taste. If you need more volumes, use high gain, if you don't need high volumes, use low gain.

 

[nightanole]

gain is a multiple of your voltage peak to peak of your source. So a bantam has a voltage of 2.9vpp. with a gain of 2 that makes it 5.8v, gain of 4 makes it 11.6v.

You want your gain as low as possible. Just enough that your headphones start to distort. That way the most sound signal gets to the amp, which makes it the best quality.

So get your quietest lineout source, turn the volume all the way up. It should be distorting just a little. Congratulations you picked the right gain.


The worst thing you can do is have too high of a gain where you turn the volume a quarter of the way up and its all ready way too loud. Basicly your loosing/attenuating 95% of your signal and using just 5% for amplification.

Most people with below 100ohm cans use 4x gain or less.

there is no calculator since its both source, can impedance, and can sensitivity. 2 64ohm cans, 1 with 110db sens, and 1 with 120db sens, one will need 2x the gain to achieve the same sound level.

 

[thefallenangelx]

well...actually im misunderstanding something...

if the impedance is higher (50, 100, 200, 600) dont i need more gain?

ure talking bout volume....but isnt gain nd volume two different things?

 

[thefallenangelx]

Quote:

Originally Posted by nightanole /img/forum/go_quote.gif gain is a multiple of your voltage peak to peak of your source. So a bantam has a voltage of 2.9vpp. with a gain of 2 that makes it 5.8v, gain of 4 makes it 11.6v. You want your gain as low as possible. Just enough that your headphones start to distort. That way the most sound signal gets to the amp, which makes it the best quality. So get your quietest lineout source, turn the volume all the way up. It should be distorting just a little. Congratulations you picked the right gain. The worst thing you can do is have too high of a gain where you turn the volume a quarter of the way up and its all ready way too loud. Basicly your loosing/attenuating 95% of your signal and using just 5% for amplification. Most people with below 100ohm cans use 4x gain or less. there is no calculator since its both source, can impedance, and can sensitivity. 2 64ohm cans, 1 with 110db sens, and 1 with 120db sens, one will need 2x the gain to achieve the same sound level.

Thank you!Just got it!