[Review] JDS Labs Objective2 Amp
Feb 10, 2015 at 7:06 AM Post #46 of 60
Well, it will actually not stop charging at all, just the current when charging is so low, that batteries will never fail because of that. It's exactly like a car battery: if charged on the car will not overload, but if charged on dedicated powerful charger may blow away if left more than 12-16 hours. :)
 
So, no worries to overcharge O2. :wink:
 
Feb 13, 2015 at 2:07 PM Post #47 of 60
Hello all. I have been thinking on making myself an Objective 2 but when I went through that list of parts given out for its design some of them are discontinued or on backorder. So I started to wonder if their is a more updated list of parts for this device that is more current and maybe even some upgrades and such. Does anyone have an info on this?
 
And Yes I know I can just buy a Kit with all the parts but I kind of like buying such parts from my usual supplier. Plus if I do build this O2 I will be getting the PCB and Enclosure from JDS Labs but as for the rest of it I was going to order it elsewhere along with parts for a few other devices. I sort of wanted to add it all into one big order.
 
Anyways any info on if their is an updated list of parts would be appreciated. Thanks :)
 
Feb 13, 2015 at 11:03 PM Post #48 of 60
There are many companies still building the O2 amp, mostly because it's great neutral and power sound, but also because of the price and DIY kits.
 
You can find original parts if you look harder or maybe better, try reading http://www.agdraudio.com/Page13.html for substitutes.
 
Cheers!
 
Feb 15, 2015 at 12:40 AM Post #49 of 60
  Hello all. I have been thinking on making myself an Objective 2 but when I went through that list of parts given out for its design some of them are discontinued or on backorder. So I started to wonder if their is a more updated list of parts for this device that is more current and maybe even some upgrades and such. Does anyone have an info on this?
 
And Yes I know I can just buy a Kit with all the parts but I kind of like buying such parts from my usual supplier. Plus if I do build this O2 I will be getting the PCB and Enclosure from JDS Labs but as for the rest of it I was going to order it elsewhere along with parts for a few other devices. I sort of wanted to add it all into one big order.
 
Anyways any info on if their is an updated list of parts would be appreciated. Thanks :)

 
Only the power jack has been discontinued. The O2 PCB was updated in 2013 to accept common 2.1x5.5mm barrel jacks, such as CUI p/n PJ-002A.
 
The original Bill of Materials contains suitable alternatives for other items.
 
Feb 15, 2015 at 6:25 PM Post #50 of 60
  There are many companies still building the O2 amp, mostly because it's great neutral and power sound, but also because of the price and DIY kits.
 
You can find original parts if you look harder or maybe better, try reading http://www.agdraudio.com/Page13.html for substitutes.
 
Cheers!

Thanks that is exactly what I was looking for. Thanks :)
   
Only the power jack has been discontinued. The O2 PCB was updated in 2013 to accept common 2.1x5.5mm barrel jacks, such as CUI p/n PJ-002A.
 
The original Bill of Materials contains suitable alternatives for other items.

This is good to know as well. Thank you. :)
 
Mar 9, 2015 at 2:23 AM Post #52 of 60
I just bought a second power adapter for work and noticed the adaptor I ordered is only 12v.  I ordered Triad WAU12-200 W.  The site said it would work with Objective 2.  Then I read on the back it says 14v.  Then on another site it said this :
 
"The Objective2 strictly requires an AC-to-AC transformer, with minimum 13.50VAC output (14VAC+ recommended)."
 
Did I order the wrong PSU?  Is there a different brick for ODAC version.?  I have the o2+ODAC.
 
Mar 9, 2015 at 11:02 AM Post #53 of 60
But what you quoted says low impedance headphones. Wouldn't that be 32 ohms and lower. I know that doesn't make since but it the hifiman planters it quoted are 35ohms.
I actually have momentum at 16ohms even lower.

 
The author refers not to ordinary low impedance headphones, but "rare low impedance power hungry cans", i.e., planar orthodynamics.
 
Triad's WAU12-200 was the default North American power adapter for Objective2 for years, and works well. We've since switched to another transformer model to ensure maximum long-term reliability (WAU12-200 failed at ~2% rate annually).
 
Sep 9, 2016 at 9:39 AM Post #58 of 60
To all modders out there

Have you ever thought of making o2 go even more crazier

Do a agdr mod to your o2, add a o2 booster board

I did something even more than that

Got the complete layout done by silvergold alloy, replaced components with higher quality bom(all were agdr standard but greater tolerance level)

Extra thing added were

DC voltage correction filter(0.2v reduction)

External AC isolation and line rectifier

10v li ion battery x2(8.6v, 2000mAH)
Battery has to be connected outside the enclosure
 
Sep 9, 2016 at 10:31 AM Post #59 of 60
Great dhruvmeena96,

I did some mods to my O2 as well:
- I've added back-power plug, 6.3mm output plug in front and RCA output plugs behind
- Modfied the gains according to my ODAC's output voltage (around 1.5X / 3.75X)
- I've added some ceramic and tantalum capacitor for better OPAMPs decoupling
- I've added Al radiators on top of output buffer OPAMPs
- I've replaced NJM2608 from voltage-amplification stage with Burson SS V5 (needed to remove the internal batteries for this)

Pro:
- I've noticed an increased soundstage, clarity and musicality

Con:
- There's no space to fit the batteries because of the SS V5 opamp
 
Sep 10, 2016 at 2:35 AM Post #60 of 60
I know bout burson audio....those guy are just too smart

They instead of making more technically superior(they are by the way, 36miV/s) vs sparkos lab

They did it in pure solid state fashion where they were able to compare and calculate more parameters

That is for v4


I have v5 dual....but it is used in agdr objective desktop amp

I use v5i in o2

As the difference isnt much and v5i with booster board(modded) in o2 is far better than just v5d on vas

I have extremely low dc offset...even more higher current drive, 10x lower noise -152db, more stability

My sound gives far more stage than just v5d

In oda, v5d makes a huge difference but then there i have space and booster board already installed....



Ok ssv5d on agdr oda>ssv5i +booster board o2>>> v5d o2
 

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