[Solrighal]

Check this out...

http://www.head-fi.org/t/730167/do-i-need-an-amp-well-im-glad-you-asked/0_40#post_10787299

 

[adydula]

Several updates on the ODA amp from AGDR at DIYAUDIO.COM....

He has sent the ODA  to Mike G and Mike has done measurements that are posted here and at DIY Audio. Mike also hooked up the ODA and played his 15" Alec's with the ODA....amazing etc.

AGDR is working on some THD measurements and has received the ODA back from Mike G and has modified it and will be sending it back for round two... of testing.

Mike has possibly discovered a THD issue with the original O2 with the volume pot being at mid way etc..AGDR has been analyzing this and thinks he knows what the issue might be. Its still below audible hearing etch.

You can read the techie stuff again over at DIY Audio.

That said none of this affects the sonic equality at all but AGDR being a perfectionist has continued to make improvements to the ODA. None of them really would be audible but makes the ODA better, safer from line input transients and more easy to build. So the latest V2.1 boards are going to be sent out shortly after he gets parts from Mouser. The 2.1 can be seen in this thread above and photos.

Details on the 2.1 revisions are listed in great detail on agar's Google drive under the 2.1 area.

I will be updating my 2.0 ODA with a few of the component updates, one being a transport across the AC power inputs to help with any surges, two regulator capacitors from 10uf to 22uf..based on data sheet errata, no sonic issue here, just one of a corner case oscillation possibility.... and a Pico amp fuse in series with one of the ac line inputs.

Also the big news is that agar asked me to share he will be offering ODA BOARDS with the small hard to solder SMD parts' Here is his post:

"In other news I have decided to sell ODA boards with just the SMD stuff soldered on for an additional $39 labor fee plus the $32 or so worth of SMD parts. All as time permits, lol, which will probably mean weekends, just doing them as ordered. If you run into anyone in your travels wanting a through-hole only ODA, feel free to point them to the posting:"

You can send AGDR a pm directly and/or read the post at diyaudio in the vendor area.

Alex

 

[James-uk]

Good morning. Just thought I would add to the pot of subjective impressions regarding O2 vs more expensive designs. In this case it's vs the benchmark dac1. Ever since getting into hifi I've wanted the Dac1 because it is a well built dac/amp designed around an objective approach to accurate sound. the only problem with this level of engineering was the cost especially here in the uk. Anyway because the dac2 is now out it's been discounted heavily so got a really good price . I knew already it wouldn't sound different to the O2 because I trust the science so I didn't buy it for better SQ , I just wanted the O2 sound with more versatility , especially the optical port for use with my PS4. Anyway I've been listening extensively and it sounds identical to the O2 . No surprises but it is nice to confirm with my own ears. Have a great day everyone.

James.

 

[adydula]

Cool....there ya go!
 
Enjoy
 
Alex

 

[Solrighal]

That's saved me money.

 

[James-uk]

That's saved me money.

Indeed. Just highlights yet again what an achievement the O2 /odac are. Like I said I only needed something different because if connectivity but for USB audio odac / O2 are all anyone needs for perfect hifi reproduction.

 

[Solrighal]

I'm honestly of the opinion that 'coloured' amps are simply a con.

 

[James-uk]

Off topic but Are we allowed to link eBay items to head fi? Now I have the dac1 I don't need the hdvd800 anymore .

 

[liamstrain]

I'm honestly of the opinion that 'coloured' amps are simply a con.

 
You can, through negligence or intent, force enough problems into an amp to audibly affect the sound. So in that respect, it's not a con. My question is, why would you? And that part may be. 

 

[pearljam50000]

Hi, i got the Geek Out, and read that it's similar to the ODAC/02 , my question is how similar, and if there is any point in getting the ODAC/O2?

 

[Solrighal]

You can, through negligence or intent, force enough problems into an amp to audibly affect the sound. So in that respect, it's not a con. My question is, why would you? And that part may be. 

Yeah, that's what I think too. Sure, if you feel your headphones are too bright then an option might be to buy an amp which is warm to compensate, but why not get a transparent amp in the first place and then choose headphones with a signature you're happy with?

Synergy? Bah, humbug.

 

[liamstrain]

Right. I try to get as transparent as I can from a hardware perspective. If I want a "warmer sound" I'll use an EQ.

With that said, I do like the slight harmonic distortion of some tube amps...

 

[Solrighal]

Yeah, but at least you're conceding it is actually distortion. It's when people use words like 'better' that's annoying.

 

[hekeli]

Well honestly it's pretty easy to jump into inexperienced facts and conclusions. But having had lots of mid- to semi-highend stuff like the HD800 / Benchmark DAC2 / CMA800R combo, any differences I've personally found to ODAC/O2 are pretty subtle at best. Sometimes I felt O2 being slightly more "difficult" or "disruptive" to follow, but yeah that's the subjective and sighted stuff for ya.. I keep my CMA800R just in case.

 (But could be my O2 was even gradually going bad since now it's kaputt with hissing pot and imbalance)
 
I tried the $6500 EAR HP4 today with my HD800's. I'd (again personally) never pay that much for the subtle warming/smoothing I think I heard.. but I did end up going home with HE560's which actually make a different sound... well duh.. 

 
In addition to the already ditched DAC2, I've comparisons with ODAC and my new HRT HD (using the CMA800R as quick A/B switch). Nothing there really. But uh I still like to keep the HD for XLR and 20 effective bits as measured by stereophile.. didn't pay much for it used either..

 

[liamstrain]

Oh yeah, I hold no delusion that my sometime preference for what is a measurable flaw, constitutes anything like "better."