[Paul Blythe]

I'd go for a 1-2 on the main build, but up this to 4-5 if you plan to use off-board inputs etc...

Personally going with a custom built destop case, rear mount power and phono inputs, plus relocated volume pot and 1/4" output... Hardest bit so far was figuring out which of the holes on P1 & P2 corresponded to the left/right channels. But I've not sarted on the case work yet, which I'm hoping to feature brushed aluminium & mahogany... Ooo..

 

[cheapskateaudio]

 
Quote:

I'd go for a 1-2 on the main build, but up this to 4-5 if you plan to use off-board inputs etc...

Personally going with a custom built destop case, rear mount power and phono inputs, plus relocated volume pot and 1/4" output... Hardest bit so far was figuring out which of the holes on P1 & P2 corresponded to the left/right channels. But I've not sarted on the case work yet, which I'm hoping to feature brushed aluminium & mahogany... Ooo..

I agree with that as a relatively inexperienced builder I can say you basically need a soldering iron and common sense to complete this project at its most basic.  
 
That sounds real nice by the way, I thought about test drilling a wood panel for the front just to see if I could be accurate enough, and I thought it might look really good too... I decided in the end to just send off a design to FPE. I'll drill the back panel though since it won't be dependent on the board placement and any precision, or lack thereof, will be purely cosmetic.

 

[Hennyo]

Quote:

Interesting, even a cable believer can appreciate the O2.

dude, gtfo.
 
I got my board today! Thanks to the unnamed for the awesomesauce order/distribution of these boards. Smooth/Slick job!
 
I fully expect it to be better than MiniMAX, but we'll see. MiniMAX is a good hybrid design. Ultimately transparency is the goal! 'Wire with gain' from every reviewer does sound good.

 

[Satellite_6]

Quote:

dude, gtfo.
 
I got my board today! Thanks to the unnamed for the awesomesauce order/distribution of these boards. Smooth/Slick job!
 
I fully expect it to be better than MiniMAX, but we'll see. MiniMAX is a good hybrid design. Ultimately transparency is the goal! 'Wire with gain' from every reviewer does sound good.

I was simply highlighting the difference in ideologies. I don't know why you are consistently a ****** on this forum. 
 

 

[Vladco]

 
Quote:

1. Hennyo

I got my board today! Thanks to the unnamed for the awesomesauce order/distribution of these boards. Smooth/Slick job!  
I fully expect it to be better than MiniMAX, but we'll see. MiniMAX is a good hybrid design. Ultimately transparency is the goal! 'Wire with gain' from every reviewer does sound good.

Hennyo you comparing apples and oranges. O2 is a good portable and minimax is a desktop amp. IMHO you system lack decent source and interconnects. If you will keep open mind you'll be surprised.
Vlad

 

[Head Injury]

Quote:

Hennyo you comparing apples and oranges. O2 is a good portable and minimax is a desktop amp. IMHO you system lack decent source and interconnects. If you will keep open mind you'll be surprised.
Vlad

What does portable vs. desktop matter? The O2 has as much power as any regular desktop amp.
 
I'm not even gonna start on the source and interconnect comment 

 

[Hennyo]

Quote:

What does portable vs. desktop matter? The O2 has as much power as any regular desktop amp.
 
I'm not even gonna start on the source and interconnect comment 

^ Top..
 
^ bottom
 
Not to mention he obviously... lol.
 
Mainly I'm interested in it's uncolordness. HDP puts out about the same amount of power, (If not quite a bit more at low resistances) but the O2 will be 'wire with gain' more clean than it. While the HDP amp is quite good and imparts much slam. It is also slightly colored. (tilted upward to become/sound more analytical) I look forward to the comparison.
 

 

[cheapskateaudio]

 
Quote:

 
Hennyo you comparing apples and oranges. O2 is a good portable and minimax is a desktop amp. IMHO you system lack decent source and interconnects. If you will keep open mind you'll be surprised.
Vlad

O2 drives the heck out of the HD650's. It makes them more revealing, less dark, and totally removes the "veil" that many complain of. If there is a difference between the O2 and a high-end desktop amp it's that the O2 does almost nothing to be polite despite impolite source material. A few really good high-end amps will show you everything but protect you from that harshness on the top end that CD's frequently have on them. That's pretty much the only difference I can think of between the O2 and a higher end amp. The O2 could safely be described as "analytical".
 
 

 

[samsquanch]

Just built mine, sitting here at work listening to it, did fine with my first three test songs (pink floyd - money, led zeppelin - since I've been loving you, neil young - needle and the damage done), but kind of faltered at my last test song, Slayer - Angel Of Death.  It became, somewhat, a jumbled mess, no definition of instruments, the guitars and bass kind of smear together.
 
I need to do some more listening, but so far this won't be my go to amp for faster metal.
 
Also...  I'm noticing some DC offset, I'm going to let the batteries charge up then do some measurements.

 

[cheapskateaudio]

 
Quote:

Just built mine, sitting here at work listening to it, did fine with my first three test songs (pink floyd - money, led zeppelin - since I've been loving you, neil young - needle and the damage done), but kind of faltered at my last test song, Slayer - Angel Of Death.  It became, somewhat, a jumbled mess, no definition of instruments, the guitars and bass kind of smear together.
 
I need to do some more listening, but so far this won't be my go to amp for faster metal.
 
Also...  I'm noticing some DC offset, I'm going to let the batteries charge up then do some measurements.

Can you measure it with the wall wart too? I just checked out the Slayer song on iTunes, sounds pretty good to me, but I'm by no means a metal afficionado. At lower volumes it did sound like the fast drum beat was somewhat out of sync with the guitar. 

 

[Willakan]

Quote:

At lower volumes it did sound like the fast drum beat was somewhat out of sync with the guitar. 

If the amplifier can change the beat of the music, I'm building eight, claiming it was my design and demanding a fellowship from the AES.
 
@samsquanch:
 
What kind of DC offset problems? Giant thumps when the headphone is plugged in?
 
 

 

[bcg27]

Quote:

If the amplifier can change the beat of the music, I'm building eight, claiming it was my design and demanding a fellowship from the AES.
 

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.
 

 

[cheapskateaudio]

 
Quote:

Quote:

At lower volumes it did sound like the fast drum beat was somewhat out of sync with the guitar. 

If the amplifier can change the beat of the music, I'm building eight, claiming it was my design and demanding a fellowship from the AES.
 
@samsquanch:
 
What kind of DC offset problems? Giant thumps when the headphone is plugged in?
 
 

I promise you, IT CHANGES THE BEAT, it played BACKWARDS and I heard SATANS SONG coming out of my headphones. HOLY **** SLAYER + O2 IS AWESOME.
 

 

[Willakan]

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.

 
I would expect that monstrous amounts of phase distortion would sorta acheive that, but not in a neat "The drum beat changed" sort of way.
As for the O2's phase shift, there's a graph on NwAvGuy's blog - 'tis flat, fortunately. 

 
 

 

[samsquanch]

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.