[Reticuli2]

Seriously?  Is this new news?  You're the man... man!  So we'll just be able to switch them on the fly without soldering?
 
Quote:

I'll be providing a complete set of gain resistors with every amp(and they will be socketed), so you can change them later to try different settings

 

 

[upstateguy]

Quote:

I don't really own any "famous" amps to compare it to.  The closest is my XM6 which you could say is "Jude Approved".  I think that the O2 has less high frequency distortion (seems to be most noticeable with m SE530s for some reason) than the XM6 but I wouldn't put to much stock in me saying that without a blind test which I haven't done because I don't have any switchboxes.  I should probably have built one myself by now but I haven't been feeling well lately.
 
I could ramble on about about things I think I heard or that something "felt" right when I listened to it but those kinds of subjective impression invariably change with my overall state of mind.  It doesn't help that differences between even vastly different amps tiny compared to differences between most headphones.  If you use headphones that it can drive properly (which some might say is cheating a bit...) even my Bottlehead Crack OTL tube amp is more similar to the O2 than almost any two headphones of different models I've owned.
 
I can feel intellectually honest describing all kinds of differences between headphones because they're usually large, easily measurable, and in 99% of cases its impossible to do a blind comparison so a sighted test is the best subjective impressions get.  OTOH it doesn't feel honest to go into that type of detail about most amps I've owned myself.  The differences are usually small enough that it becomes quite difficult to filter out by biases.  That's why most of my review focused on more concrete things.
 
I can tell you that I enjoy it quite a bit, but I can't give a definitive answer as to the exact reason why.  It could be that it really is as clean and transparent as the numbers say and I like it because that happens to match up with my preferences.  It could be I only think its as clean and clear as the numbers say which I know would match with my preferences if it was actually true.  It could be because I trust and respect Lord Voldermot.  It could be because he sent me one for free.  It could be innumerable other things I haven't accounted for.

 
Hey Mav
 
How is the "spaciousness" compared to the Crack amp? 
 
My GS-1 has a spaciousness and clarity to it that is not present in my M^3 or Woo3 amps.  I used to say that the GS-1 has a greater resolution and plays in a larger space.  When Asr did a review of the GS-1 he called the same thing "holographic".  What ever it is, it has made the GS-1 my favorite amp and I was wondering if you found a similar quality in the O2.
 
Of my portables, a Hornet and a Portaphile, neither of them sound as good as the desktops.
 
I can't wait to get my O2 and compare it to both my portable amps and my desktops.  The headphones I'm going to use are the T-1s, 650s, 880s and 701s.
 
A question:  Does the O2 sound better to you on battery or AC?  Or, are you unable to detect a difference?
 
E
 

 

[maverickronin]

Quote:

How is the "spaciousness" compared to the Crack amp? 
 
snip
 
A question:  Does the O2 sound better to you on battery or AC?  Or, are you unable to detect a difference?

I can't really answer the first one all that well.  Since I sold my HD650s the only 'phones I have that actually work that well with the Bottlehead are my YH-3s.  That's kind of surprising for a planar, but its mostly because of their 150 ohm impedance that keeps the Crack from running out of current and clipping at very low volumes like my T50RPs.  Anyway, the YH-3s don't have a large soundstage to begin with and I don't hear either amp sounding too different in that specific area.  I think it does sound a little more "spacious" with my T50RPs than my other amps which they work with.
 
 
As far as battery vs. AC goes, as long as the drop in the supply rails from being on battery isn't enough to make it clip at the current input voltage and gain I don' hear any difference.  Even plugging and unplugging it while something's playing and even with really sensitive 'phone my SE530s.  As far as I can tell the only difference is that you can get more power on AC.
 

 

[Uncle Erik]

Thank you for the impressions. Yet another reason for me to consider this amp.

However, I'm holding out for the dedicated desktop PCBs. 99% of my listening is at home.

I plan to drop it into a custom case and add it to the rig.

 

[Shike]

Quote:

Thank you for the impressions. Yet another reason for me to consider this amp.

However, I'm holding out for the dedicated desktop PCBs. 99% of my listening is at home.

I plan to drop it into a custom case and add it to the rig.

It's going to be quite a long time before the desktop version comes out as far as I understand.  This is perfectly able to be used as a desktop amp without batteries as is, since I too will mostly use it at home (though with my "transportable" rig I take on extended travel).  You could just as well put this in a full size enclosure and wire to the board as long as you pay attention to layout (I believe NwAvGuy mentioned it at one point).  A gain of 3 and 2 as I mentioned before should cover almost any source except select exotica items (certain tube output players iirc).
 
Still, if you're willing to kick back and wait months/in absolutely no hurry then it's hard to fault such a stance too.
 

 

[Willakan]

Desktop version is a few months away as I understand it.

 

[The Monkey]

The "sound quality" between the desktop amp and the current version should be minimal, if any, correct? The original design was compared to a desktop amp, right?

 

[khaos974]

The "sound quality" between the desktop amp and the current version should be minimal, if any, correct? The original design was compared to a desktop amp, right?

Yes, the difference in SQ should be minimal, the difference is mostly about accepting hotter less common sources and having everything mounted on the board, plus RCA and 1/4" connectors.

 

[dachness]

Enclosure Specs if any one was wondering: http://www.boxenclosures.com/category/product_details.html?product__id=211292

 

[Reticuli2]

Ipods can output 6V?!

 
Quote:

For home only use I'd go with 2x and 3x myself.  This means you're safe up to ~3.5 volts input.  Of course you limit the maximum voltage too should your source output average or below (6V output power or less depending).  For me 2x and 6x was the best compromise since I can use it with a wide range of home sources and even crank 6V out from an ipod when I travel.

 

 

[Shike]

Ipods can output 6V?! 
 

No, they output 1V. With 6x gain it's 6V

 

[i_djoel2000]

Quote:

No, they output 1V. With 6x gain it's 6V

i thought ipod can only outputs 0.5V throught its line out

 

[Shike]

i thought ipod can only outputs 0.5V throught its line out

I'm not using the line-out?

 

[Reticuli2]

Nevermind.  You're saying you are using the line out.

 

[Shike]

Nevermind.  You're saying you are using the line out.

I'm using the headphone out > O2 . . .