The Objective2 (O2) Headphone Amp DIY Project

Hello,

I know it's always a bother to have people like me complaining on their first post on thread, but well I do have a little problem :)

I've build my O2 yesterday, and althought everything should be workin perfectly fine, I've got no sound...

I've got the little pop that say the O2 is on, I've got every tension righ, every resistance right... And no sound.

No distorsion, no hiss, just no sound :eek:

Did anyone have this problem, I mean, everythin is ok, but NO sound :DD
 
Hello,

.....

I've got the little pop that say the O2 is on, I've got every tension righ, every resistance right... And no sound.

No distorsion, no hiss, just no sound :eek:

Did anyone have this problem, I mean, everythin is ok, but NO sound :DD


When you say 'everything ok' do you mean that you have been through the whole of RocketScientist's/NWavGuy's testing procedure and it all checks out?

If not, or if you've missed a bit out, then that's the next step.

If any numbers don't check out then at that point it's worth posting back with the numbers.

Here's hoping you haven't done all the tests yet... :rolleyes:
 
I'm afraid I(ve done all the troubleshotting ,and yes EVERYTHINS is fine...

I'll do more tests tonight, I've tested it with ultra sensitive earphones, and where ther is no hiss, I could hear a little fumble of sound , as if they were 0.00001% of the original sound :DD

And again no distorsion, no hiss, no fuzz, no sound o_O


I'm guessing that your input jack's negative terminal isn't connected properly, or your gain-stage opamp (NJM2068) is having a problem or isn't soldered correctly on every pin. Are you testing in the enclosure or out of the enclosure?

Any others out there have better diagnostic suggestions? :confused:
 
O2 custom case

I think it was roughly three weeks ago that I posted about making a purpose built case for my O2, at the time I showed a cardboard mock-up of the case...

Things have progressed a little and I'm now at the priming & painting stage of the build...

O2case-1.jpg

The original cardboard mock-up (rear) and the plastic version.

O2case2-1.jpg

Outer and inner module.

O2case3-1.jpg

The inner module separates into three; case, rear panel and inner brace.

Not quite sure what colour to paint the outer, pure white or with a funky design!? Hope you like.

Paul
 
I'm afraid I(ve done all the troubleshotting ,and yes EVERYTHINS is fine...

I'll do more tests tonight, I've tested it with ultra sensitive earphones, and where ther is no hiss, I could hear a little fumble of sound , as if they were 0.00001% of the original sound :DD

And again no distorsion, no hiss, no fuzz, no sound o_O

I had the same problem, it turned out that my pot wasn't connected properly.
 
I'm afraid I(ve done all the troubleshotting ,and yes EVERYTHINS is fine...

I'll do more tests tonight, I've tested it with ultra sensitive earphones, and where ther is no hiss, I could hear a little fumble of sound , as if they were 0.00001% of the original sound :DD

And again no distorsion, no hiss, no fuzz, no sound o_O

Hi Res pics will help in the diagnosis.. ;)
 
I don't know if this has been brought up if you want the ac connector in the back using the B3 case you have to be careful, most of the panel mont jacks on mouser have continuity to the outer section to the panel mount, with the B3 having an aluminum rear panel you have to add insulating washers which don't come with the panel mount jacks. Its a potential gotcha.
 
I'm "back" after a few days away for the holiday. It seems everything is humming along nicely here without me :)

@nanotechnos, I agree with the suggestions already made. I would suspect your source, cabling, you're using the wrong jacks, or a ground problem with the input jack or output jack. Did you by chance remote mount the input jack or otherwise use any other method for the input? If so, there are two traces that have to be cut on the PC board if the input jack is also installed on the board. Use your DMM on the OHMS range to check the resistance of the input pins on P1 to ground with your input cable plugged in. If they read close to zero you or "open" (infinite resistance) you found the problem.
 
Welcome back RS!

A question about this:

"
USB Audio Class 1 Compliant – Unlike most pro-audio interfaces that support 24/96, the ODAC requires no problematic proprietary drivers for XP, Vista, Windows 7, OS X or Linux. It’s true Plug-And-Play. It also does not require UAC2 drivers, like some DACs, which are not provided in any current version of Windows.
"

Now, can it be used as an native uac2 device in OS'es supporting uac2?

Brgds
 
The ODAC is not UAC2--that's an entirely different (and generally expensive) animal. It's 24/96 driverless UAC1. Any OS supporting UAC2 also supports UAC1.

There's no significant objective benefit to UAC2 for playing 2 channel audio. But there are disadvantages (most notably needing proprietary drivers for Windows and more issues with drop outs).

:)

In this case my concerns were not windows centric. The other os'es have the drivers so why not open it up? The market would increase as I see it + if the firmware is open there would be another feather in the objective hat!

Yes or No will do...

Brgds
 
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