[cheapskateaudio]

 
Quote:

IF the Objective2 isnt the world-beater some of us thought it would be (for the money), its interesting that no-one has come forth to accept Voldemort's challenge. I guess everyone is just too damned busy with other things.

Why is that interesting? It's an idiotic challenge, I don't want to donate $500, I want to WIN $500. If I was going to pocket $500 I would do it right now.

 

[cheapskateaudio]

 
Quote:

Have you checked the regulator with a DMM to see if it's still working? These chips can take quite a bit of heat. I once removed a much smaller and more delicate usb controller chip that I thought was fried with lots of flux and a small kitchen blow torch. Turns out when I tested it, it was still working even after all that abuse.
 
 

Semiconductors *are* very fragile. You may heat one up and find it works because they're designed to withstand heat. But long before the IC completely burns up, it will suffer reduced performance characteristics, permanently if it is heated up too much or for too long.
 
If anyone here has ever overclocked their computer they probably know that once you heat damage a CPU it won't overclock anymore, and you'll be lucky if it's still stable at stock speeds. So while it may turn on, boot up, and let your browse the internet, you won't be gaming on that CPU anymore.
 
 
 
 

 

[kiteki]

Quote:

 
Why is that interesting? It's an idiotic challenge, I don't want to donate $500, I want to WIN $500. If I was going to pocket $500 I would do it right now.
 

What are you rambling on about.
 
If you win the challenge you don't have to donate anything, if you think your version of the O2 is superior and it's clearly audible, then why not take up the challenge? Then he will donate $500 to a charity of your choice.
 
If you want to pocket the cash yourself, email him and ask if he'll bend the rules for you, I'm sure he'll wire $50 to you directly, then perhaps you can pick up one of those oscillators at a flea-market.
 

 

[Willakan]

Okay, we have a supposed measurable difference, on a pair of headphones that NwAvGuy owns. I think I can spot a way of getting to the bottom of this!
 
EDIT: De-typo'd.

 

[Groundloop]

Quote:

 
If anyone here has ever overclocked their computer they probably know that once you heat damage a CPU it won't overclock anymore, and you'll be lucky if it's still stable at stock speeds. So while it may turn on, boot up, and let your browse the internet, you won't be gaming on that CPU anymore.
  
 

The difference in manufacturing process for a CPU and an IC, designed in mid 80's is like night and day. You can easily degrade modern 32nm CPU, but have fun duing that on some old 65 nm one, using quite differenet transistor technology. So, depending on the process, the degradation in different IC/transistors is quite the difference.
 
 

 

[kiteki]

 
cheapskate you have to be more professional about this, what exactly did you "see in a PDF document"?
 
 
I look at the O2 as a reference portable amplifier, perhaps it changes in sound a bit with capacitor or OPAMP rolling, I will try a couple different OPAMPS when I receive it just for fun, but that's not really the point of the project.
 
Personally I think this hobby is quite subjective because we use different equipment, different sources, different DAPs, different music and different acclimatisation (getting used to bright/dark IEM's/HP's over a length of time) at different volumes, with different levels of music intoxication, so using a reference amplifier or reference DAC, and listening to the same internet radio station when judging IEM's/HP's is a welcome attribute to the discourse of this community imho.
 
There are lots of scattered reviews and they rarely mention the relative source, amp, music or transducer used and then there is brand and price favoritism as well, and people say "it's all subjective" when I don't think that's necessarily the case when you peel the fruit and look at the seeds.
 
 

 

[DRUB]

Quote:

 


I mean that in REW, under 50hz, the FR curve is all over the place on the stock amp, and tightly controlled down to 20hz on the modded amp.
 
And yes, the regs get hot... I'm not sure how anyone could use the WAU16-400 and not feel that the regs are a tad hot, though they don't burn to the touch until a few hours have gone by. That's the nasty thing about heat, especially in a sealed enclosure, it saturates over time... Sure you check it after 30 min and it's ok, and it's a bit hotter after an hour, but check after 5-6 hours of music driving HD650's or something similar, with a hot input, and charging batteries. If one was to leave the amp on 24/7 with the WAU16-400 I'm pretty sure the v-regs will burn up or significantly degrade within mere weeks or possibly days.

 

According to Voldemort's measurements, the overall response is +/- 0.07 dB from 10 hz to 48 Khz and only -.0.04db at 20hz, -0.5db at 5hz.
 

http://i.imgur.com/e7bb7.png​

 
^ measurement graph above.
 
@Cheapskateaudio: you are an untrustworthy reviewer/measurer/builder. You have not built the stock O2 correctly, otherwise it would not have a messed up frequency curve below 50hz. Stop making baseless claims!
 

 

[kingpage]

Somebody please help him build one properly... Or people could all chip in to send a working O2 to him.
 
Forgive me. This is just too entertaining!

 

[SobbingWallet]

Quote:

Okay, we have a supposed measurable difference, on a pair of headphones that NwAvGuy owns. I think I can spot a way of gettign to the bottom of this!

The first thing to do would be to measure cheapskate's stock model on a reliable test bed, since it sounds like it isn't performing to spec given the flakey bass and overheating.  In the event the stock amp measures well, the modded one sounds like it won't, due to the blindly audible difference.  If that's the case, the modded amp simply wouldn't apply for the challenge.  (It's easy to make an amp sound different, but the challenge is meant to demonstrate that audible differences will show up in the usual metrics as well, because audio is not magical.  "Amps that measure the same are amps the sound the same" is pretty much a tautology after all, and only a diehard subjectivist would really try to dispute it.)  This is just a choir member preaching to the choir though.

 

[kiteki]

 
Hey, what's the best Watt rating to use on the soldering iron when assembling the O2?
 
 

 

[kingpage]

25W is usually recommended for through-hole soldering. A larger range would be 20-30W.

 

[upstateguy]

Quote:

Why is that interesting? It's an idiotic challenge, I don't want to donate $500, I want to WIN $500. If I was going to pocket $500 I would do it right now.

Hey Cheapskate
 
I don't remember seeing any hi-rez pics of your two builds.  Both sides of the board would be nice. 
 
Leave the EXIF on the pics for verification.
 
Post pics or you didn't build anything and you're just flapping your gums.

 

[mikeaj]

Well it's pretty obvious that you can improve the stock -0.04 dB at 20 Hz, but I don't think anybody would interpret rolling off a few hundredths of a dB from 50 Hz to 20 Hz would constitute "under 50hz, the FR curve is all over the place on the stock amp" as claimed and pointed out earlier.  I don't think anybody else has documented FR issues with the stock build (including me; I ran it through RMAA at least, if you don't want to believe the designer's charts).
 
To me, pictures would be nice, but this is something easy to check that should be able to be crossed off the list quickly.
 
Weird low-frequency response can easily be gotten through ambient conditions changing if you're doing microphone measurements, so I have no idea why you would want to use something that finicky unless you're sitting in an anechoic chamber and have a studio recording setup.  Why not measure the output of the amp directly?  You can do so with the amp loaded with the headphones or not.  (or somehow you think that if amp A and amp B send the same signal, the response of the headphones will be different, so only measurable differences will show up after the transducers?)

 

[kiteki]

Well he measured after the transducers with the silver cables.
 
I'm still waiting for the microphone recordings of stock cable and silver cable so we can listen to the claimed 20% difference, and photos of the testing rig with the microphone fixed in the same spot.
 

 

[LizardKing1]

And I'm still waiting for that mythical FR curve where the stock is "all over the place". Also, you can't first say "my stock version sucks compared to my modded" and then say that your stock version isn't really stock. If you want to show how your up/down/side-grade is better, you have to compare to a stock O2. Unless I misinterpreted what you said and the components are the same.
 
On the other hand, don't dismiss the fact that he might have figured something out. As soon as he actually has some objective evidence (although waiting to be posted here), the first response is "well your stock O2 was probably broken". What happened to objectivity?