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Old 11th November 2011, 05:54 PM   #701
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@Mr.Slim: It happens on both gain settings. I will check the gain resistors.
I have tried 3 headphones just to make sure its the amp.

@Shadow 419: I would say the imbalance is about from the 0 to 1 range, roughly 6mm.

When there is no source, its completely quiet

Thanks guys.
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Old 11th November 2011, 06:15 PM   #702
MrSlim is offline MrSlim  Canada
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Quote:
Originally Posted by 454Casull View Post
Will we see a head-to-head with the Wire headphone amp?
How about a Wire/Beta 22/CK2III/O2 comparison? I'm finishing a 3 channel B22 for a friend, have CK2III and should be able to finish "The Wire" in the next couple of weeks.
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Old 11th November 2011, 11:13 PM   #703
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I finished soldering all of the components on the board except the ICs, regulators, and MOSFETs. I have a few questions though:

-Has anyone had alignment problems with the battery snaps? I have 3 of them perfectly aligned, but one of them is very slightly leaning back. Would that cause any problems when connecting the batteries?

-Even if I installed all the components in the battery circuit, could I still run the amp off of AC power only?
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Old 12th November 2011, 12:07 AM   #704
sebash is offline sebash  United States
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Quote:
Originally Posted by dewasiuk View Post
I finished soldering all of the components on the board except the ICs, regulators, and MOSFETs. I have a few questions though:

-Has anyone had alignment problems with the battery snaps? I have 3 of them perfectly aligned, but one of them is very slightly leaning back. Would that cause any problems when connecting the batteries?

-Even if I installed all the components in the battery circuit, could I still run the amp off of AC power only?
My battery prongs aren't exactly aligned, but I did use a dead battery to position them, as long as you can attach a battery and it sticks I'm guessing it should be fine.

you can run the amp off of AC power only even with all the battery components installed, I do this and haven't had any problems.
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Old 12th November 2011, 01:14 AM   #705
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Almost forgot, what is the advantage of soldering in the vias under C9 like the construction tips say?

Quote:
Originally Posted by sebash View Post
My battery prongs aren't exactly aligned, but I did use a dead battery to position them, as long as you can attach a battery and it sticks I'm guessing it should be fine.

you can run the amp off of AC power only even with all the battery components installed, I do this and haven't had any problems.
I'll have to wait untill I order and get my batteries to see if I didn't screw up lol.
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Old 12th November 2011, 03:10 AM   #706
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Quote:
Originally Posted by ohmer View Post
@Mr.Slim: It happens on both gain settings. I will check the gain resistors.
I have tried 3 headphones just to make sure its the amp.

@Shadow 419: I would say the imbalance is about from the 0 to 1 range, roughly 6mm.

When there is no source, its completely quiet

Thanks guys.
Nature of analog volume pot. If it's only happening at the very lowest volume level and you can deal with it leave it be. If it's really bugging you, you can buy a few pots and use the one that tracks the best. Analog volume pots will have some imbalance at the lowest volume levels.
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Old 12th November 2011, 04:08 AM   #707
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Thanks, it's great to hear it wasn't my shoddy work. =)
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Old 12th November 2011, 03:43 PM   #708
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Looking at the P mosfet(FQU17P06TU) through the package, I noticed that the metal tab is cut off for some reason. Was anyone else's part shipped like that?
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Old 12th November 2011, 05:49 PM   #709
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My FQU17P06TU also looks like the tab was cut off.
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Old 12th November 2011, 07:50 PM   #710
mikeaj is offline mikeaj  United States
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I finally got around to installing battery prongs (and wow they're so misaligned), but I soldered them in using a dead battery as a guide, so at least they will fit batteries...crookedly.

The bigger issue is that it seems like the power management circuit is not working correctly. I get a DC offset of like 4 mV with AC power or with battery only power, measured at P2 pads. With battery only power and one battery removed, it goes to 200 mV or so. However, with the other battery removed (and the other one battery put back in), it's more like -2V. Docs say that the offset should be more like 600 mV or under with either battery removed. This is indeed a potential problem, at least if running on batteries?
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