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Objective Desktop Amp.....A Version from AGDR - Page 4

post #46 of 54
Thread Starter 

There's a new build of the ODA over at DIYAUDIO if anyone is interested:




You can follow this persons build to see if you think you might want to tackle the project!



post #47 of 54
Originally Posted by adydula View Post

Hey I have used my DIY ODA for almost a year now and its as good and better than the O2, which I have 2 and have AB tested them.


The ODA is hands down more versatile and more powerful than the O2.


We are waiting on a second round of objective measurements and some re-check measurements on the O2 itself.


You can build one or there may be a site that might in the near future be selling them



Are there any downsides or caveats I should be aware of before deciding to purchase the parts to build AGDR's desktop o2 amp? I am mostly interested in the fact it's an original o2 but with the connections on the back panel. I'd also enjoy the benefits he's introduced but am weary of any issues that may be introduced with his changes. Have most of the downsides and issues he had with his first version been fixed by now?

post #48 of 54
Thread Starter 



The only downsides is it costs more, and you have to build it......other than that there are no real downsides that I know of.....you can send AGDR a PM and ask him directly.


Also over at diyaudio.com site there are hundreds of posts from many builders etc all about the ODA.


Some state its better soundwise than the O2, In my AB tests I cant tell.....but there are many others benefits of the ODA over the O2 that mea a lot to me and maybe to you or not...


If you decide to build one you will find the folks at DIY will be there as will AGDR to help you along if needed.



post #49 of 54
Thread Starter 



Another ODA takes flight!!!


This is a set of pictures of the desktop O2 variant that was completed by a person in Europe, with the ODAC integrated into the case.


These ODA's are rare, and becoming very desirable compared to the original O2.


Details can be found over at diyAudio in the headphone section.


Note: Missing knobs because the builder is looking for knobs with red markings.



Edited by adydula - 9/7/15 at 5:04am
post #50 of 54
Try using burson audio V5(designer component, but worth every penny)instead of lme49990 with DC precision opamp 827....believe me...

This will take you to another world of audio

Actually not tested by dscope

But slew rate, oscillations and lower distortion rate are superior till 40KHz vs adgr default oda till 38khz(distort....small jigyness) vs orignal oda at 26khz

Sound fantastic, its true about burson opamp transparency...it sounds like without walls and soundstage to huge without loosing signature...its like more cleaner and with instrument seperation...

But the price will go ****ty up

And agdr, thanks for updating nwavguy oda
post #51 of 54
Use Burson audio v5 Dual in VAS(voltagr amplification stage...much cleaner than njm2068 orignal and a lot better than lme49990 dual....but the issue is the price then.

No oscillation as such till now (100mhz oscilloscope) and is better.

I am doing computer hardware engineering from india and i have learnt that spec sheet dont always show everything.. it is design

Plus this opamp is superior in both specs and design...just cost is issue

Slew rate min 36V/microsecond and max is 49V

Just that you would be limited to +/-15v supply voltage

Best part of this amp is same neutrality but far far far cleaner or i will say the cleanest treble of all opamp

I am using O2 and it took a new level in soundstage(airyness) with this amp

This is to Alex "adydula" and all those who want signature change or i will say even more cleaner sound(and the term cleaner is drastically clean and this not hiss or rf but signal cleaning, dont know how this opamp does it but yeah its true)
post #52 of 54
Thread Starter 

Take a look at the new TI chip OP1688....AGDR the designer of the ODA has built several versions and has contact with the engineer in TI that was

involved in this chip that was made for headphones in particular...


I have built three of them now, all abit different and its as clean and transparent as anything I have listened to..





post #53 of 54
I know about super cmoy...both you and agdr is famous in my locality.

Some people even say that you guys are the successor of chu moy and nwavguy(this is truth).

So i wont question it

But regarding opa1688/9, both were designed to basic hi fi amplifier with low slew rate.....plus i am using opa1688, it is a nice opaamp..or i would say best on price and beats the orignal muse01 by 100x times transparency...

And features are also nice

But when it comes to sound, sorry alex....burson goes on different league

The upgrade for opa1688 in terms of sound is sparkos lab ss3602.

Ummm about opa1688 bad part is lower slew rate, heat issue(i am facing) and tick type of sound from basic cmoy.....that tick type of sound didnt come from my friend's custom cmoy...which he named cmoy pro

Cmoy pro features

-Super CMOY all feature
-adjustable gain from 2x to 12x by alps
-trickle charge "active play" and quick charge switch "no play"
-ebl 600mAh 9v li ion x2
-bass boost linkwitz
post #54 of 54
Thread Starter 

The Cmoy we have built with the 1688's have no tick or pops, dead silent and sound as good as the original O2...


I have listened to Burson and for the money its not that much better....They make nice stuff, but its expensive and just not worth the money on that higher end to me.



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