The Objective2 (O2) Headphone Amp DIY Project

[Jelle Schrijver]

Originally Posted by sgrossklass

Keep in mind that while DC of a few volts will not damage the O2, it can still drive the input amp into clipping since it's amplified with the same gain as the signal there.

The ODA will hopefully have an extra coupling capacitor (bipolar 'lytic should do) and input pull-down resistor. I guess space was too tight in the O2.

Where can I read more about the ODA. Looking forward to the dac part, since I am in the market for a good usb dac. So far I only saw very little info came by in this thread.

[Jelle Schrijver]

@jokener; this iron has served me well; basetech ZD99. And it is more in the spirit of the O2, though less impresive.

[MrSlim]

Originally Posted by Jelle Schrijver

Where can I read more about the ODA. Looking forward to the dac part, since I am in the market for a good usb dac. So far I only saw very little info came by in this thread.

NWAvGuy's Blog will get you about as much info as the rest of us have...

[MrSlim]

I think I'm in love..
http://www.amazon.com/gp/product/B00...n=&s=&v=glance

[qusp]

I wouldnt waste youre money, ive had pretty crap experience with even their standard clone of the hacko hot tweezers. the ceramic element isnt user, or perhaps even factory serviceable and mine failed within the month. i found it difficult to even buy the whole tweezer set by itself,so i just threw it in the trash

[agdr]

Originally Posted by Jokener

I think I'll go out and buy a new soldering station first, though.
A Weller station from the 80s is good and well, but I think a shiny new Ersa i-Con 1 is in order...
(Or would you guys recommend strongly against it or strongly FOR something else?)

I have xytronics FWIW. I had my first one 15 years (analog temp controlled!) and just wore it out. Bought myself two new toys last year

https://www.jameco.com/webapp/wcs/st...001_2099180_-1

https://www.jameco.com/webapp/wcs/st...001_2114685_-1

XYtronic-USA

If I were doing it now I would get the one with that includes the tweezers

https://www.jameco.com/webapp/wcs/st...001_2099219_-1

and/or the one with auto power reduction

https://www.jameco.com/webapp/wcs/st...001_2099201_-1

I did all my O2s with the 0.4mm (1/64) connical tip.

This rework station is pretty cool too

Xytronics 988DTP Digital Soldering, Desoldering, and Complete Rework Station

[MrSlim]

Meh, guess I can stick with my $30 ebay clone... although this looks useful:
http://www.amazon.com/gp/product/B00...A1UB0766FG4V9I

[sofaspud]

I agree with qusp, to a certain extent. Let's try to be diplomatic (I'm not very good at it though).
I see an entire page here that makes it look a lot like one needs a $200 DMM to make any diy progress. I completely disagree. A $5 analog meter is much better than no meter at all, and I'd implore newcomers to make at least that investment.

We all reported the issues just like you asked and this is how you reply. I only suggested that based on the evidence that maybe there was a bad batch of components.

konga, if that is your suggestion, how on Earth is RS supposed to know any better than you or me or anyone else here? He's good; no doubt. But is he that good? I'm not sure what you want him to do, but it seems there clearly are conditions on how he does it. Voluntarily, mind you.
I'm up to date to last week or so on "that other thread" and it's beyond silly. And the main perp admits to not knowing mud from Shinola. As someone mentioned already, it's for entertainment purposes only.
There isn't a big issue with the voltage regulator tabs touching the case of the O2. The 7812 tab is ground, and the 7912 tab is the input. Neither will cause reg chip failure, but the situation is unwanted. Those with "too high" voltage regulators, it seems to me at this point, didn't use the BOM part or didn't install it correctly. If the latter, it also seems easily remedied with a little resoldering.
For those with O2 problems seeking help, don't be afraid. Long distance troubleshooting can be frustrating to both sides. Don't give up. Just remember that the accuracy of the information received will be directly proportional to the accuracy of the information given. PM me if you'd like; my bark is worse than my bite I assure you.
There seems to be a rash of regulator failures, unlike anything I've ever been aware of. These are jellybean parts, so if it is "a bad batch" behind it all, it shouldn't be long before the official news gets out. Personally, I'm skeptical that bad chips are the cause.
To RS I have only to say, no good deed goes unpunished.
I decided not to kludge my (backordered) volume pot connections, so my O2 isn't operational yet. I've just been implementing some mods, setting others aside, and working on more. Hitting that power switch for the first time will already be more interesting than I ever imagined. And that's still without the cans plugged in!

[ethanolson]

Originally Posted by agdr

I did all my O2s with the 0.4mm (1/64) connical tip.

What benefit would I have to using such a small tip to build my O2? It seems too small to be as fast as the larger tip I'm rolling with right now (a fatty 3 or 4mm). Seriously, I'm not soldering 603 or 0402 resisters or caps onto mine. Anyway, I'm totally open minded because you are far more experienced than I and do something that I haven't.

[agdr]

Originally Posted by ethanolson

What benefit would I have to using such a small tip to build my O2? It seems too small to be as fast as the larger tip I'm rolling with right now (a fatty 3 or 4mm). Seriously, I'm not soldering 603 or 0402 resisters or caps onto mine. Anyway, I'm totally open minded because you are far more experienced than I and do something that I haven't.

Probably no benefit for soldering the O2 up - it is just the tip I like to use. In the other direction though - unsoldering - the fine tip rocks for getting one lead of small resistors out. I can wedge the tip under the resistor lead right above a pad, give it a second to heat, then just lift the lead right out of the hole with the tip.