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What after CMOY as portable amp? - Page 6

post #76 of 78
6/28/10 at 6:16am
Thread Starter 

those are the pix of what i did

 

_DSC4744.jpg_DSC4745.jpg

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post #77 of 78
6/28/10 at 9:22am
Quote:
Originally Posted by thefallenangelx View Post

Actually the only thing is that isnt that portable...at least as i did!1000uF are really tall and so the package i made (in wood) isnt that little to be portable!!i should do something to let the power caps be smaller!-_-


From your picture I can see that you use 50V capacitors; 16V (or even 10V) would be enough and those would be considerably smaller. If not shorter then at least thinner.

Quote:
Originally Posted by thefallenangelx View Post

Actually got a problem:

 

- headphone connected, cowon d2 connected and ON (no music anyway), i hear some hiss in the right channel

- headphone connected, cowon d2 connected but OFF, hear some noise in both channel...

- and when i switch to off the amp, i hear a loud "pop" on the right channel!

 

In this thread you say you use OPA2111 and in the other thread you write OPA2107. Are these problems the same with both opamp types? What do you hear when you connect the phones directly to the Cowon?

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post #78 of 78
6/28/10 at 10:25am
Thread Starter 
Quote:
Originally Posted by kvant View Post


From your picture I can see that you use 50V capacitors; 16V (or even 10V) would be enough and those would be considerably smaller. If not shorter then at least thinner.

 

In this thread you say you use OPA2111 and in the other thread you write OPA2107. Are these problems the same with both opamp types? What do you hear when you connect the phones directly to the Cowon?

 

Yep i know but the electronic shop had juste them!-_-

 

oh sorry for getting u confused!

 

Forget about 2111.

Im using 2x 2107 and there was those issues...and im right now with 2x 2132 but the same thing happen!

 

Anyway i just:

 

- put decoupling caps (0,1uF)+

- lowered gain to 3.2 (R1=1K, R2=2,2K)

 

= same issues but lowered (of course)

 

Any help to remove hiss and noise buzzle when headphones on and no sources in?

 

I dont have any volume pot...so should i put some resistance on the input?

 

oh, if anyone can please help me...i just opened a new thread bout the problem on:

 

http://www.head-fi.org/forum/thread/499605/apheared-47-hiss-noise-problem#post_6744501
 


Edited by thefallenangelx - 6/28/10 at 11:55am
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