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So, the Objective2 headphone amp - designed entirely around the measurements? (PLEASE READ RULES... - Page 2  

post #16 of 1042
Quote:
Originally Posted by SpaceTimeMorph View Post

I put two orders into mouser for the parts, and am working on gathering some of the other stuff... but should be pretty quick once the boards are done.  I just want to error check as much as possible... it is a pretty solid design by the looks of it.  And all I have are Pro 900's, e3c's, ... yep nothing hard in this camp either.


Boards? wink.gif Is there already a boards run underway or something?

 

I'll be doing it point to point, dead bug style over here.

 

Man, if Tyll weren't on the other side of the world, I'd give it to him. The shipping would be more than the parts cost though, and I don't think he will particularly fancy some robot vomit in a wooden box.

post #17 of 1042
Quote:
Originally Posted by deadlylover View Post


Boards? wink.gif Is there already a boards run underway or something?

 

Naw, I just mean whenever he gets the new layout done; I want to follow through with his PCB layout rather than point to point.  From what I can gather, that point (no pun intended) is still a couple of weeks out.  Even better for me, though.  End of August time frame is promising to be less busy at work than the craptastic pile of poo that I am dealing with right now...

post #18 of 1042
Shouldn't this be in the DIY sub forum?
post #19 of 1042
Thread Starter 

The DIY subforum gets a lot less traffic - besides, the reason I put it in Sound Science is because I thought that some people would want to bring up whether the measurements taken are the whole story, as Currawong already has, which is more of a Sound Science thing IMO.

 

Also, deadlylover, doing it point to point would not achieve anything like advertised performance. Layout and grounding has to be extremely carefully optimised for the amplifier to measure well (NwAvGuy makes a point of it in his second article on his amp)

 

Finally @Currawong, NwAvGuy mentions that his testing involved " playing real music into assorted worst case loads"


Edited by Willakan - 8/6/11 at 12:23am
post #20 of 1042

That's good to hear.  It should really be in DIY, as that would include any measurement discussion.

post #21 of 1042
Quote:
Originally Posted by Willakan View Post

 

Also, deadlylover, doing it point to point would not achieve anything like advertised performance. Layout and grounding has to be extremely carefully optimised for the amplifier to measure well (NwAvGuy makes a point of it in his second article on his amp)

 

I seriously doubt I will COMPLETELY balls up the amp by doing it point to point. Since I mess around with amps that can kill me so often, I like to pretend that I half know what I'm doing when it comes to DIY.
 

Doing it point to point with everything star grounded with the shortest possible signal path should still be 'on nodding terms' with the PC board layout. I would hate to think the design is so sensitive and unstable that it will perhaps oscillate itself to death if I don't use the PC board.

 

Come on, what's the worst that could happen? A slightly higher noise floor? Let's be real here, it's a bloody simple amp.

 

I'm not going to go all 'nwavguy' on the O2 when I make it, I just thought that it would be nice to have some honest listening impressions compared to a well known amp like my balanced b22. I'm not setting out to bag on the O2 or anything, I absolutely hate dynamic headphones anyway, I really couldn't care less on how it compares to my b22. If it sounds just as good, then that's what I'll say, there's nothing to it.

 

I'm not even going to bother anymore.

post #22 of 1042
Thread Starter 

I'm sorry, I'm just passing on what NwAvGuy said about his own design:

" Moving a single track can change the distortion from 0.005% (-86 dB) to 0.1% (a lousy –60 dB). Really!"

I don't think that is particularly novel as far as any high-performance design goes. Routing is not done well simply to lower the noise floor or just to get the shortest signal path. Whilst it would be possible to achieve high performance with a point-to-point approach, it would be very far from trivial.

Why all the rage?


Edited by Willakan - 8/6/11 at 3:37am
post #23 of 1042
Quote:
Originally Posted by Willakan View Post

I'm sorry, I'm just passing on what NwAvGuy said about his own design:

" Moving a single track can change the distortion from 0.005% (-86 dB) to 0.1% (a lousy –60 dB). Really!"


I find that a little hard to swallow.

 

se

 

 

 

post #24 of 1042
It must be an extreme case, moving a track from its optimal position to the less desirable position possible, otherwise, I agree it's hard to believe.
post #25 of 1042
Quote:
Originally Posted by Willakan View Post

I'm sorry, I'm just passing on what NwAvGuy said about his own design:

" Moving a single track can change the distortion from 0.005% (-86 dB) to 0.1% (a lousy –60 dB). Really!"

I don't think that is particularly novel as far as any high-performance design goes. Routing is not done well simply to lower the noise floor or just to get the shortest signal path. Whilst it would be possible to achieve high performance with a point-to-point approach, it would be very far from trivial.

Why all the rage?

 

Yeah I'm sorry man, my bad. I just thought I was taking one for the team by cooking up another prototype, so I got a little bit offended when an armchair guru with no hands on experience pretends to know what he's talking about when it comes to DIY.

 

I completely agree that proper board layout matters, but one does not simply compare it to point to point wiring, they're really different as one usually does not have to make the same 'compromises' as when routing a PC board. Sure, you won't get the modern niceties of a ground plane and susy, but I'm not going to go into that.

 

I don't know if it's just my pathetic DIY experience kicking in, but the O2 is an extremely simple amp (that's not a criticism), it would be REALLY difficult to completely balls it up when doing it point to point. tongue.gif

post #26 of 1042
Quote:
Originally Posted by deadlylover View Post

Yeah I'm sorry man, my bad. I just thought I was taking one for the team by cooking up another prototype, so I got a little bit offended when an armchair guru with no hands on experience pretends to know what he's talking about when it comes to DIY.

 

I completely agree that proper board layout matters, but one does not simply compare it to point to point wiring, they're really different as one usually does not have to make the same 'compromises' as when routing a PC board. Sure, you won't get the modern niceties of a ground plane and susy, but I'm not going to go into that.

 

I don't know if it's just my pathetic DIY experience kicking in, but the O2 is an extremely simple amp (that's not a criticism), it would be REALLY difficult to completely balls it up when doing it point to point. tongue.gif


The parts are cheap enough. Do us a favor and make it point to point, then measure it smile.gif

post #27 of 1042
Quote:
Originally Posted by Steve Eddy View Post


No. Why?

 

se

 



Thought you could do a run of populated boards like you did for the jack plug.

 

No reason why you couldn't make something on it.  If it turns out to sound as good as nwavguy says it will, it's going to be a big seller...  even for finished products.

 

I'm going to build one, but they're so inexpensive I'd also buy a populated board to see if there's any difference.

post #28 of 1042
Thread Starter 

I'm familiar with the disadvantages/advantages of point-to-point wiring vs PCBs. As I say, by all means have at it, but even simple point-to-point audio circuits require some degree of planning - and you have doubtless read the various articles on it where people complain how two point-to-point wired identical products sound different due to wiring variations (admittedly guitar amplifiers, which are not exactly comparable).

Whilst a point to point circuit hugely simplifies things in some ways, there are still various concerns to deal with (parasitic capacitance ect) but it is a relatively simple design and you seem to know exactly what you're doing.

You have to measure it after you're done thoughwink_face.gif


Edited by Willakan - 8/6/11 at 1:15pm
post #29 of 1042
Quote:

Originally Posted by upstateguy View Post

 

Thought you could do a run of populated boards like you did for the jack plug.


Well, I had 100 of those jack plugs made and I still have about 90 of them left. frown.gif

 

Quote:
No reason why you couldn't make something on it.  If it turns out to sound as good as nwavguy says it will, it's going to be a big seller...  even for finished products.

 

I prefer to say away from other peoples' toys.

 

I'm sure someone will pick up the ball and run with it though.

 

se

post #30 of 1042

I stumbled upon the O2 schematics the other day and actually do intend on building one.  This should be interesting,  no matter what the result is.

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