The Objective2 (O2) Headphone Amp DIY Project

[Stealth3si]

sorry here's the pudated pics the previous post was too smalll

pic 1
http://img29.imageshack.us/img29/212/o2groundlead4.jpg

pic 2
http://img827.imageshack.us/img827/8...ackwiring5.jpg

the scond picture it shows the ground..is that where i'm supposed to solder in the wire to ground it to the case?

fyi, nwavguy's article says its important to ground it to the case to reduce noise and humm

[lorriman]

Originally Posted by Stealth3si

sorry here's the pudated pics the previous post was too smalll

pic 1
http://img29.imageshack.us/img29/212/o2groundlead4.jpg

pic 2
http://img827.imageshack.us/img827/8...ackwiring5.jpg

the scond picture it shows the ground..is that where i'm supposed to solder in the wire to ground it to the case?

fyi, nwavguy's article says its important to ground it to the case to reduce noise and humm

I'm intending to do this one day myself but so far I've rarely been troubled by noise or hum, ungrounded.

[Turbon]

There seems to be something wrong with my ODA/ODAC combo since there is quite some hiss accompanying the music :-( It's as a radio station slightly out of tuning.

I just got the ODAC last evening so I haven't had any opportunity yet to troubleshoot.
My first move will be to get the combo out of the box to eliminate ground problems...

Only hissing, no hum.

Brgds

[lorriman]

Originally Posted by Turbon

There seems to be something wrong with my ODA/ODAC combo since there? is quite some hiss accompanying the music :-( It's as a radio station slightly out of tuning.

I just got the ODAC last evening so I haven't had any opportunity yet to troubleshoot.
My first move will be to get the combo out of the box to eliminate ground problems...

Only hissing, no hum.

Brgds

Is your 'ODA' using RS specified parts or modded? And have you done the grounding as described by RS?

[Turbon]

Yes lorriman, everything up to specs...

[Stealth3si]

In order to ground it, can I just use an electrical tape to keep the wire in contact with the ground circuit silvery thingy?

[litster]

Hi, I am new here. :-)

I am putting an O2 parts list on mouser.com. I have a couple questions.

For J1, Is 163-7620E-E the replacement for the obsolete 163-7620E?

For transformer, is 412-218054 better than WAU16-400 because it higher in voltage and amp?

Thanks.

[ethanolson]

Originally Posted by Stealth3si

In order to ground it, can I just use an electrical tape to keep the wire in contact with the ground circuit silvery thingy?

You want to solder it to the ground post on the underside of the audio jack like RS did it. Electrical tape won't give you what you want. Also, you want to scour the part of the case it will contact as well as the wre end that's touching the case. The screwed in front plate will apply enough pressure... much better than electrical tape. So don't solder that part.

It would be OK to use the lead wire from a resistor or capacitor as you previously questioned, but beware that you only get a few bends out of that kind of wire before it snaps.

[ethanolson]

Originally Posted by litster

Hi, I am new here. :-)

I am putting an O2 parts list on mouser.com. I have a couple questions.

For J1, Is 163-7620E-E the replacement for the obsolete 163-7620E?

For transformer, is 412-218054 better than WAU16-400 because it higher in voltage and amp?

Thanks.

The replacement power receptacle you listed is your best option, but beware that the blades are a bit larger so they will need to be filed or vertically crimped to fit in the PCB holes.

Also, the unloaded voltage of that Xicon AC adapter is 21V. Just think about that for a bit.

[Turbon]

OK.
1: Take out your O2 PCB from the box. Get rid of the front panel.
2: Take the batteries out.
3: Find something as thick as the slots in the box.
4: Take whatever measure you like to keep the odac connected to the space below the batteries with component side down. I used tape that is adhesive on both sides. The tape is made for rugs/mats I believe.
5: Now this is the tricky part... We need new front and back panels that fits a O2/odac combo where the box itself has been turned upside down and the oda goes into slot 2 and the odac into slot 1 counted from the new bottom. I got rid of the Al structure in the middle of the box not to interfere with the inductor which is othervise in contact with the box.
6: The frontplate - all holes must move 2mm's up.
7: I have done this on my own but I don't have the measurements at hand. Just Put the odac into slot 1 and measure the distance to the usb hole...

I will buy a few If anyone else is interested in a fitting combo and someone wants to get this happening... Otherwise I'll make my own but since the ones for O2 was much better than I'll ever could produce I'll rather see that someone made a GB out of this!

This way you will have it all - O2 and ODAC in a B2 enclosure with batteries :-)

Brgds

BTW: I confess - I took some electricians tape to be sure the regulators won't shortcut to the lower top in the box...