O2 Build Complete: Let the objective, subjective listening tests commence!
Nov 30, 2011 at 3:58 PM Post #511 of 721
Quote:
Nahh, it's mostly due to his possession of the Elder Wand. (dscope
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Those things don't grow on trees, and if those bad boys were more accessible(cheap), I can't help but feel that the entire objective side of audio would make a nice leap forward.


Yep.  The dScope is key.
 
I'd love to to be able to do that kind of stuff.  I'm hardly an expert, but pretty much anyone could learn to run a few basic test routines and then post the results.  At the moment there are a lot more things I need to or want to spend 5 figures on which rules out that plan.
 
Nov 30, 2011 at 5:10 PM Post #512 of 721
 

...he will be able to design an amp from the ground up that outperforms O2 for a fraction of the cost.


No.
 
An amp that outperforms the O2, yes, but not without an increased parts count or going to more costly parts only available in SMT. For a fraction of the cost, no. And it's highly unlikely that anyone will accrue the expertise in months.
 
Oh, and the difference between datasheets and high-end audio is generally a lot of hot air, as the O2 (and The Wire) demonstrate.
 
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Nov 30, 2011 at 7:34 PM Post #513 of 721
 
I was trying to tell those guys how absurd it sounds. It takes a genius and a half plus enough fundamental knowledge to pull off something like that. They talked as though everybody could become nwavguy (no links, so it's okay). And now, the scope made it happen like it is some sort of general AI that doesn't need human intervention (It's a freaking tool for goodness sake, why not try telling people that the hammer and the measuring tape are key to building a house instead of the carpenter)
 
 
Nov 30, 2011 at 9:05 PM Post #514 of 721


Quote:
 
I was trying to tell those guys how absurd it sounds. It takes a genius and a half plus enough fundamental knowledge to pull off something like that. They talked as though everybody could become nwavguy (no links, so it's okay). And now, the scope made it happen like it is some sort of general AI that doesn't need human intervention (It's a freaking tool for goodness sake, why not try telling people that the hammer and the measuring tape are key to building a house instead of the carpenter)
 



I think deadlylover was only being half-serious though with his "Elder Wand" comment though.  He seemed to be just trying to lighten the mood a bit.
 
Nov 30, 2011 at 9:14 PM Post #515 of 721
I just tried to listen to some music on my O2, it made a high pitched squeal and then silence. The both pos and neg regulators are now running extremely hot. Ugh! 
 
 
 
 
 
 
Nov 30, 2011 at 9:47 PM Post #518 of 721
Looks like it's U6 or something along it's circuit. Right after I turn on the amp U6 starts to heat up, U5 remains cool.
 
Maybe I'll spend the extra coin and get a "name brand" regulator from TI, National, or Fairchild. 
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Quote:
Clearly the amp wasn't designed for music, only test tones 
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LOL Thanks Head Injury :)
 
I guess I'm back to my desktop amps until I can gather enough parts to order to make it worthwhile.

 
 
Nov 30, 2011 at 10:10 PM Post #519 of 721
My amp used to be working perfectly, but somehow recently the negative regulator (7912) decided to conk out I think.  It may have been after handling the board to touch up some poor solder joints.  I now get like 11.9V across the positive side 7812 but 0V across the 7912, at least according to my cheapo DMM.  I guess I'll order a couple more 7812 and 7912 just in case.
 
I only noticed there was a problem when there was a significant click on power off.  I think for the last listening session, the positive rail was given from AC power through the regulator, while the negative rail was given from one of the batteries.  Hybrid operation!
 
Looks like the power management is still working since the DC offset at the output is 4 mV with the negative battery in and the positive side on AC power (or with two batteries).  With no batteries and AC power, it shuts off and there is around 200 mV.
 
Dec 1, 2011 at 12:14 AM Post #520 of 721
it really does sound like there is an issue here now that we have repeated similar findings, perhaps i/we owe a certain someone an apology on that front. it doesnt mean that a couple parts changes means its a better amp, just a functional one and thus sounds better. it seems like the regulators are a weak point and are either just dodgy parts, or are being overstressed in some way.
 
Dec 1, 2011 at 12:25 AM Post #521 of 721
Anything is possible I guess.  I've had mine built since  November 10th and with daily use of at least 4 hours.  Most days it's closer to 6-7 hours, and I've yet to have any issues. I'm running strictly on ac if that might make a difference. 
 
Dec 1, 2011 at 12:29 AM Post #522 of 721
Maybe a bad batch or QC issues with maker. I also don't like the fact that they are so close together on the board. When I replace them I may just reverse mount on if there is space in the B2 case.
 
I was also running on AC since my batteries have not arrived yet.
 
 
Dec 1, 2011 at 12:33 AM Post #523 of 721
Quote:
I was trying to tell those guys how absurd it sounds. It takes a genius and a half plus enough fundamental knowledge to pull off something like that. They talked as though everybody could become nwavguy (no links, so it's okay). And now, the scope made it happen like it is some sort of general AI that doesn't need human intervention (It's a freaking tool for goodness sake, why not try telling people that the hammer and the measuring tape are key to building a house instead of the carpenter)

 
Lord Voldemort had lots of help from his fellow Death Eaters, you should check out the credits/shoutouts somewhere, it's not like he solo'd the whole thing. The Elder Wand played a critical role in his cunning scheme, after all, good measurements were the driving force in developing the amp.
 
Wow, so many regulators letting out their magic pixie dust. Aaaand that's why you always buy a boatload of spare parts when doing DIY, I think I have a dozen or so spare regulators and opamps. Sour about the guys who only purchase the minimum amounts from the BoM, extra shipments hurt. =/
 
Maybe I should leave mine on full tilt 24/7 to see if I can fry the regulators on purpose, and if I succeed multiple times, I'll try it again while strappin' on some heatsinks. Mine was strictly on AC as well, I had a regulator that only worked when it felt like it. I'm too lazy to look for the mouser baggies, I think mine were Fairchild.
 
Dec 1, 2011 at 12:54 AM Post #524 of 721
I have an idea for the regulator problem.  Disconnect batteries and lift one end of the D1/D5 blocking diodes. Connect some resistors that mimic the average load imposed by the amplifier.  Reconnect when the regulators pass all tests, then test the amp circuits with the opamps unplugged. And so on.
 
Dec 1, 2011 at 12:56 AM Post #525 of 721

 
Quote:
 
Lord Voldemort had lots of help from his fellow Death Eaters, you should check out the credits/shoutouts somewhere, it's not like he solo'd the whole thing. The Elder Wand played a critical role in his cunning scheme, after all, good measurements were the driving force in developing the amp.


 
If "good measurements were the driving force in developing the amp" like you say, then isn't it also the case for graphic designers and civil engineers? Or any other industry that relies heavily on tools? Should we start disregarding just about every single person that has used some tools for their designs (audio or otherwise)?
 
While everybody (not literally) is criticising how O2 sucks, he who must not be named is about to release details about his upcoming ODA (desktop amp+dac). A new and better thing for people to bash, yeah!
 

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