[anthonyhong]

Hey guys, I just put this together last night and going through the initial checks (The Mini³ Portable Stereo Headphone Amplifier), I am having a problem.

The Sanity checks were okay, but with the quinescent current check I am getting a reading of 100 mA :|

Any ideas?

 

[MisterX]

Proceed to the rail splitter and DC offset "checks" and report your findings.
Pictures also help.

 

[anthonyhong]

Hey MisterX, thanks for your reply

I'll try to get some pictures later, but in the mean time:

1) Rail splitter:
on V- and V+, 6.83V
on V- and IG 3.4V

2) DC offset check:
on OG to IG ~ 1mv, then it slowly drops to 0
on OL to IG ~ open
on OR to IG ~ open

opamp dead

?

 

[anthonyhong]

Pictures

 

[ShinyFalcon]

If you have the multimeter set to mV DC try putting it to the hundreds range (200), to see if the offset is somewhere in the tens.

And do try reflowing those joints (pins 5, 6, and 8) on the AD8397

 

[anthonyhong]

Hi guys

I haven't been home lately so I didn't get to work on it, but I took another look this morning.

I reflowed the chip like you suggested ShinyFalcon, and well I think a few things got sorted out, however the current check still reads at 100.

Redoing the dc current check, it now reads:

on OG to IG ~ 4mv
on OL to IG ~ open
on OR to IG ~ in the decimal places

I figured it wont hurt to plug it in, so I tried it with some audio source, I can hear sound coming from it but the output constantly crackles- if that helps at all for any diagnostics.

edit: and the left channel doesn't work

 

[dumbears]

From my bad experience with AD8397, it can easily be fried while you're busy soldering other components. If you're pretty sure that there're any cold joints, it's probably time to say goodbye to it.

Hope this is not the case.

 

[anthonyhong]

Update

Crackle was me being stupid, I fixed that up... the amp now... 'works' but its only one channel

I think I'll go ahead and order another chip, and see how it goes from there