Review: JDS Labs O2 (Black edition) + O2/ODAC discussion
Jan 24, 2013 at 10:24 AM Post #226 of 543
Antonio!!
 
German Weiss bier!!!
 
Now were talking!!!
 
Ayinger as well!!
 
Alex
 
beerchug.gif

 
Jan 24, 2013 at 5:01 PM Post #227 of 543
hahaha,beeeer...
 

 
Anyway,i was surfing uselessly on the net when i found out some news for us head-fiers,when:
 
 

 
so,somebody dare to guess?
 
Jan 24, 2013 at 5:04 PM Post #230 of 543
well,i won't start a new thread cause i won't be able to follow constantly,so i will give to you a clue to ,well,we know how,around here,we use to already create Expectation-Anticipation-Pre-Appreciation threads for every products months before the supposed new device is ready to be released...
 
Fotos da Linha do tempo | Facebook
 
enjoy it!
 
Jan 24, 2013 at 6:23 PM Post #231 of 543
Quote:
well,i won't start a new thread cause i won't be able to follow constantly,so i will give to you a clue to ,well,we know how,around here,we use to already create Expectation-Anticipation-Pre-Appreciation threads for every products months before the supposed new device is ready to be released...
 
Fotos da Linha do tempo | Facebook
 
enjoy it!

asdfasdfasdf <- me being speechless
So stoked for it. Is this a portable O2? JDS Labs said it's a "tremendous upgrade to the C421" and reviews of the C421 vs O2 say they sound similar, but not quite the same.
 
 
 
On a more related note, is there a reason why some of the amplifiers don't have a feedback system? I'm taking a systems engineering course and so far it seems to be a universal agreement that negative feedback is really good in a system since it "improves fidelity of the output signal" and "resists internal and external changes via a buffering mechanism (in this case it's the op-amp I think)". Op-amps usually amplify the difference between the inputs, so if there's no negative feedback, wouldn't small errors be larger than if there was a feedback system?
 
^or maybe I should post this in the sound science forums
 
Jan 24, 2013 at 8:03 PM Post #234 of 543
asdfasdfasdf <- me being speechless
So stoked for it. Is this a portable O2? JDS Labs said it's a "tremendous upgrade to the C421" and reviews of the C421 vs O2 say they sound similar, but not quite the same.


As I remember (and I don't remember so well these days), the C421 was designed before the O2. He mentions that the C5 'measures well'; so I would suspect that this isn't the O2 since its designer had very strict conditions for re-implementation that I suspect the C5's small case make impossible, but has been designed in the spirit of the O2 with a proper audio measurement device. That being true, then the C5 could be a serious portable amp.

But we need a lot more details.
 
Jan 24, 2013 at 8:21 PM Post #235 of 543
Quote:
On a more related note, is there a reason why some of the amplifiers don't have a feedback system?

Because of irrational fear or failure to use it correctly. If done wrong it can lead to instability.
 
Feedback = good, unless you start with a bad circuit to begin with.
 
Jan 24, 2013 at 9:10 PM Post #236 of 543
How about a C5 from JDS?
 
Alex

Well you got it!
Quote:
 
As I remember (and I don't remember so well these days), the C421 was designed before the O2. He mentions that the C5 'measures well'; so I would suspect that this isn't the O2 since its designer had very strict conditions for re-implementation that I suspect the C5's small case make impossible, but has been designed in the spirit of the O2 with a proper audio measurement device. That being true, then the C5 could be a serious portable amp.

But we need a lot more details.

You got that right,their origin and purposes are clearly different,but i guess both devices have in common the will to be as much as transparent as any amp should be,as they are as a matter of fact especially when measured with proper testing devices.
I am in the process of saving money to buy a C421,but right now i am gonna wait to see how the C5 plot will develop.
Quote:
asdfasdfasdf <- me being speechless
So stoked for it. Is this a portable O2? JDS Labs said it's a "tremendous upgrade to the C421" and reviews of the C421 vs O2 say they sound similar, but not quite the same.
 
 
 
On a more related note, is there a reason why some of the amplifiers don't have a feedback system? I'm taking a systems engineering course and so far it seems to be a universal agreement that negative feedback is really good in a system since it "improves fidelity of the output signal" and "resists internal and external changes via a buffering mechanism (in this case it's the op-amp I think)". Op-amps usually amplify the difference between the inputs, so if there's no negative feedback, wouldn't small errors be larger than if there was a feedback system?
 
^or maybe I should post this in the sound science forums

To my personal very little experience in electric language,you are speaking prehistoric mandarin ,
biggrin.gif
.
Anyway ,if it would depending on me,you could still talking about sound science right here ,i always end up learning something new.
 
Jan 24, 2013 at 9:40 PM Post #237 of 543
Quote:
Originally Posted by miceblue /img/forum/go_quote.gif
 
On a more related note, is there a reason why some of the amplifiers don't have a feedback system? I'm taking a systems engineering course [...]

 
It's a marketing gimmick. Science and engineering are irrelevant.
 
Jan 24, 2013 at 9:58 PM Post #238 of 543
It's become some kind of mark of quality to not "cheat" like that.  Though mostly we're talking about global feedback.  You generally can't run these components completely open loop with zero local feedback of any kind and get a usable product; gains would be too high, for starters.
 
In a related manner, there is some kind of ambivalence, particularly among the old guard, about prepackaged ICs that do all sorts of jobs very well nowadays.  "Kids these days can't design these things from scratch" and so on.  It's maybe more interesting or rewarding to do things the hard way or alternate way sometimes, and this is feasible when selling audio products with higher than razor-thin penny-pinching margins.  Their hands aren't really forced with regards to design decisions to be competitive, outside of maybe the lower-margin stuff like some receivers and some pro audio gear.
 
Jan 24, 2013 at 10:52 PM Post #240 of 543
Quote:
Quote:
Originally Posted by miceblue /img/forum/go_quote.gif
 
On a more related note, is there a reason why some of the amplifiers don't have a feedback system? I'm taking a systems engineering course [...]

 
It's a marketing gimmick. Science and engineering are irrelevant.

Eh...okay?
blink.gif

 
Many biological systems use negative feedback to regulate/maintain processes...
 
 
 
 
Quote:
It's become some kind of mark of quality to not "cheat" like that.  Though mostly we're talking about global feedback.  You generally can't run these components completely open loop with zero local feedback of any kind and get a usable product; gains would be too high, for starters.
 
In a related manner, there is some kind of ambivalence, particularly among the old guard, about prepackaged ICs that do all sorts of jobs very well nowadays.  "Kids these days can't design these things from scratch" and so on.  It's maybe more interesting or rewarding to do things the hard way or alternate way sometimes, and this is feasible when selling audio products with higher than razor-thin penny-pinching margins.  Their hands aren't really forced with regards to design decisions to be competitive, outside of maybe the lower-margin stuff like some receivers and some pro audio gear.

So zero feedback amplifiers are more prestigious/of higher quality?
 

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