[estreeter]

Quote:

Originally Posted by cheapskateaudio /img/forum/go_quote.gif
 
Don't be too quick to stop doing comparisons, I think we could all benefit by getting to know your honest opinion of the relationship between the ß22 and the O2.
 

Well. they are both headphone amps - I think that covers it. Looking around the YMB site, the cheapest I could have a B22 built for is $1600 - whatever nwavguy may have said on his blog about the O2 being able to compete with 'more expensive amps', I dont think he had this in mind:
 

1. Featuring extremely high quality parts (see Standard features above), prices starting from $1600 for 2-channel, $1900 for 3-channel, and $2550 for 4-channel. Many options and upgrades are available. Please inquire for details.

 

Even if we assume (!) a DiYer can put the 2-channel model together with the same parts for 1/2 the price above, that is still an $800 amp. I just dont see it as a fair comparison when this isnt $800 worth of 'audio jewelry' - its widely acknowledged as one of the better designs available to DiYers.
 
 

 

[estreeter]

Happy to report that Oliver has agreed to change my gain settings to 2x and 5x - just passing this on for anyone else who intends using their (EPH-)O2 with lower impedance/high sensitivity cans.

 

[cheapskateaudio]

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Quote:

Well. they are both headphone amps - I think that covers it. Looking around the YMB site, the cheapest I could have a B22 built for is $1600 - whatever nwavguy may have said on his blog about the O2 being able to compete with 'more expensive amps', I dont think he had this in mind:
 

1. Featuring extremely high quality parts (see Standard features above), prices starting from $1600 for 2-channel, $1900 for 3-channel, and $2550 for 4-channel. Many options and upgrades are available. Please inquire for details.

 

Even if we assume (!) a DiYer can put the 2-channel model together with the same parts for 1/2 the price above, that is still an $800 amp. I just dont see it as a fair comparison when this isnt $800 worth of 'audio jewelry' - its widely acknowledged as one of the better designs available to DiYers.
 
 

All very true, but seriously, what does it *really* take to drive headphones properly?
 
I really want to know about the differences between these two amps so I can determine if I want to build a ß22 or something like it. If the two are relatively close I won't bother blowing 10x the money and time on the ß22 and look for something with more price/performance bang for the buck. A design like the ß22 is awesome, but almost a joke for a headphone amplifier.

 

[samsquanch]

Quote:

Well. they are both headphone amps - I think that covers it. Looking around the YMB site, the cheapest I could have a B22 built for is $1600 - whatever nwavguy may have said on his blog about the O2 being able to compete with 'more expensive amps', I dont think he had this in mind:
 

1. Featuring extremely high quality parts (see Standard features above), prices starting from $1600 for 2-channel, $1900 for 3-channel, and $2550 for 4-channel. Many options and upgrades are available. Please inquire for details.

 

Even if we assume (!) a DiYer can put the 2-channel model together with the same parts for 1/2 the price above, that is still an $800 amp. I just dont see it as a fair comparison when this isnt $800 worth of 'audio jewelry' - its widely acknowledged as one of the better designs available to DiYers.
 
 

Well, I built my Beta22 for just around $1000, three channel build, knock it down to 2 channels, it would probably be around $750, so your number isn't that far off, at least for mine.
 
Now, what I want to know is why you're defending the O2 so hard, without even having heard one yet?  And why are you knocking a Beta22 as "audio jewelry" when you seemingly haven't heard one either.  If you have, what were your impressions?
 
On his site he states: 
 
 

One user compared the O2 to the $1000+ AMB beta22 using $1000 Audeze LCD-2 headphones and wasn’t sure he could hear any differences.

 
I'd assume that this comparison is what he had in mind.
 
Once again, I am not out to say the O2 is garbage, it works just fine as a headphone amp, but is it, in his own words, "THE (nearly) PERFECT HEADPHONE AMP"?  No.  I made the comparison to the Beta22 because it's the best amp I have sitting on my desk, my reference point, if the O2 had blown it out of the water, I would have said so, and you'd see my B22 up for sale.

 

[bcg27]

Quote:

Well, I built my Beta22 for just around $1000, three channel build, knock it down to 2 channels, it would probably be around $750, so your number isn't that far off, at least for mine.
 
Now, what I want to know is why you're defending the O2 so hard, without even having heard one yet?  And why are you knocking a Beta22 as "audio jewelry" when you seemingly haven't heard one either.  If you have, what were your impressions?

Actually I'm pretty sure he was saying the B22 is not audio jewelry and actually has components worth that much, unlike some amps which are 95% enclosure cost with 5% spent on components.

 

[Malvin]

 
 

Even if we assume (!) a DiYer can put the 2-channel model together with the same parts for 1/2 the price above, that is still an $800 amp. 

 
In my experience: Cost of parts (including shipping) is just way below that. However, if it is someone's first build - it might get expensive considering cost of necessary tools, lack of experience, parts that were missed (not ordered) initially..
 
Plus casing this thing up adds a lot to the total cost: typical configuration involves 2 relatively large enclosures, custom front/rear panels - this is where it becomes really expensive.
 
My 3-channel beta22 was built for (i think) around $450 (and that's including backplane board, but that was almost 2 years ago, and it is still uncased).
 
But since this thread is about O2.. Out of curiosity I ordered parts to build it as well, so I guess I'll be able to contribute to this thread once it is up and running..
 
 
 
 

 

[samsquanch]

Quote:

Actually I'm pretty sure he was saying the B22 is not audio jewelry and actually has components worth that much, unlike some amps which are 95% enclosure cost with 5% spent on components.

Hmm, not how I read what he wrote, but that's besides the point.
 
This has all gotten way off topic, more reviews and comparisons!

 

[Malvin]

 
 

Now do it blind and volume-matched! 

 
I can second that. Volume-matching is absolutely necessary in any A/B test. Louder amp will is more likely to be perceived as sounding better. When levels are carefully matched, you might be surprised how close they all sound.
 
Don't get me wrong - the difference is still there. But usually it is more subtle than some people tend to describe it.
 
$600 vs. $100 headphones will arguably deliver more apparent SQ improvements than the upgrade of $100 DIY amp to a $600 amp. So for those on a budget, I think money could be better spent on a better pair of headphones rather than more expensive amp.
 
 

 

[Head Injury]

Quote:

Hmm, not how I read what he wrote, but that's besides the point.
 
This has all gotten way off topic, more reviews and comparisons!

 
I think maybe you replaced "it" and "this" with O2 when he meant Beta22. Bold text and brackets added for emphasis:
 
     Quote:

I just dont see it as a fair comparison when [the Beta22] isnt $800 worth of 'audio jewelry' - [the Beta22] is widely acknowledged as one of the better designs available to DiYers.

And yeah, more reviews would be lovely. Some objective ones would be great, but I'm not holding my breath.
 

 

[mikeaj]

Well, the O2 wasn't intended to be ultimate amp ever (maybe look at The Wire or similar for a DIY project of allegedly top class), just something close enough that nobody can tell its sound apart from the most accurate amps.  Whether that's true has yet been confirmed or denied convincingly.  Listeners so far (1) don't have top amps to compare to***, (2) haven't been blind testing, let alone properly level matching, or (3) are named NwAvGuy (also supposedly a few others he knows), who have level matched, ABX tested, and claim to hear no differences.  Of course the designer is not expecting to hear a difference, so that's not much proof of anything.
 
*** though who knows which of these top amps actually meet the same levels of accuracy
 
Sorry, my cop out is that I fall under (1).

 

[deadlylover]

Yay I'm famous, I didn't know I was featured on his site.

 
In all seriousness, the b22 is pretty much all about absolute overkill (which IMO, is the essence of DIY), the polar opposite compared to the Obj2's "good enough" design principle. The very notion of comparing the two is borderline dumb.
 
During my somewhat short level-matched comparison, I found that the Obj2 is easily "good enough" in terms of sound, which would mean a great success for the designers goals. But I still respectfully think that the Obj2 is a heap of crap compared to the b22. (I'm a *little* biased as the b22 was my first build)

 
I'd do a proper blind test, but changing the cables on the LCD-2 is a complete piss off, and while I do like the LCD-2 r.1 (the only decent dynamic I have access to), my Stax still takes wild ferocious dumps all over it, and I'd rather not subject myself to the misery.
 
When/if I throw together the desktop version, I'll build a milosz-style A/B switcher to help do a blind test.

 

[khaos974]

Quote:

ok, did the readings, these readings were done twice, once with a source connected, once without.
 
With and without the wall wart, power on is 3mV on each channel
 
Now the ugly bits.
 
Power off, with wall wart, both channels:
When turned off: spikes at 200mV
Normalizes at: 130mV
 
Power off, without wall wart, both channels:
When turned off: spikes at 130mV, then quickly drops to 50mV and begins to slowly drop
Normalizes at: 25mV
 
clicks at turn on, muffled thump at turn off.

That's documented, according to the designer, the worst case scenario is 80 mV peak into 600 ohms over a 330 Hz half cycle at turn on and a 350 mV peak into 600 ohms over a 25 Hz half cycle. Not nearly perfect but nothing that should damage your headphones.
 
Quote:

This would actually not be that difficult. All you would need is an amplifier with audible phase shift within the audible frequencies. Though I doubt this is the case, I don't recall seeing a lissajous plot or input vs output square/sine waves to show phase shift in the measurements of the O2.

That's documented too, the designer's measurements show a plus minus 0.8 degree phase shift over the 100-10000 Hz range and at worst + 5 deg at 20 Hz and -1 deg at 20 kHz. That not perfect but the phase shift should be largely inaudible, it's way below transducer  induced phase shift anyway.
 
 

 

[cheapskateaudio]

Quote:

Yay I'm famous, I didn't know I was featured on his site.

 
In all seriousness, the b22 is pretty much all about absolute overkill (which IMO, is the essence of DIY), the polar opposite compared to the Obj2's "good enough" design principle. The very notion of comparing the two is borderline dumb.
 
During my somewhat short level-matched comparison, I found that the Obj2 is easily "good enough" in terms of sound, which would mean a great success for the designers goals. But I still respectfully think that the Obj2 is a heap of crap compared to the b22. (I'm a *little* biased as the b22 was my first build)

 
I'd do a proper blind test, but changing the cables on the LCD-2 is a complete piss off, and while I do like the LCD-2 r.1 (the only decent dynamic I have access to), my Stax still takes wild ferocious dumps all over it, and I'd rather not subject myself to the misery.
 
When/if I throw together the desktop version, I'll build a milosz-style A/B switcher to help do a blind test.

I would think comparing opposite approaches is the most interesting, just to see how they differ in the real world.
 
I for one look forward to any comparisons to the ß22 as I sincerely think such overkill designs are a waste of money and effort. I'm not saying it doesn't sound awesome, I'm merely hinting that awesome need not come at such absurd levels of over-engineering. You know that saying about any idiot being able to make things bigger and more complex, I think it applies to the ß22 just a tad.
 
Now, I'm not saying that the O2 is the amp to challenge the ß22, I'm simply stating the obvious, that we should be able to DIY a design for way less than $1200 that drives the heck out of nearly any dynamic headphone on the market.
 

 

[bcg27]

 
Quote:

 
In all seriousness, the b22 is pretty much all about absolute overkill (which IMO, is the essence of DIY)

+1
 
Quote:

That's documented too, the designer's measurements show a plus minus 0.8 degree phase shift over the 100-10000 Hz range and at worst + 5 deg at 20 Hz and -1 deg at 20 kHz. That not perfect but the phase shift should be largely inaudible, it's way below transducer  induced phase shift anyway.

 
Cool, I must have missed it.
 
 
Quote:

I would think comparing opposite approaches is the most interesting, just to see how they differ in the real world.
 
I for one look forward to any comparisons to the ß22 as I sincerely think such overkill designs are a waste of money and effort. I'm not saying it doesn't sound awesome, I'm merely hinting that awesome need not come at such absurd levels of over-engineering. You know that saying about any idiot being able to make things bigger and more complex, I think it applies to the ß22 just a tad.
 
Now, I'm not saying that the O2 is the amp to challenge the ß22, I'm simply stating the obvious, that we should be able to DIY a design for way less than $1200 that drives the heck out of nearly any dynamic headphone on the market.
 

This is a hobby so just because you don't need overkill to do something doesn't mean that you shouldn't. That's like saying nobody should climb Mt. Everest because Mt. Kilmanjaro is high enough. I built the B22 because it is an interesting design and I thought it would be a challenge, and I enjoy building things. I definitely didn't do it because I needed to. Same reason I am going to attempt building the DIY T2, which makes the B22 look like a cmoy.

 
 

 

[Willakan]

IMHO, overkill is not something to aspire to if it can be proven to be pointless or even detrimental in most situations - which is the principle behind NwAvGuy's design.