[mikeaj]

Power supply voltage outputs (which the op amps and so on receive) are commonly called rails. e.g. the +7V rail

 

[adydula]

If you look at schematics, often you see the circuit diagram drawn in between a upper or top voltage bar or 'rail.
 
On the bottom of the chart you ususally see the ground level or rail....
 
To make schematic diagrams easier to understand if the distance to the upper voltage reference, source or rail sometimes you will see abbreviated shorter voltage and gnd connections, like with ops amps etc..
 
When bread-boarding the V+ is usually strung out of the top on the board and the V- or gnd reference is laid out along the bottom....so you have an upper rail and a lower ground rail...like railroad tracks....
 
Alex

 

[miceblue]

Quote:

If you look at schematics, often you see the circuit diagram drawn in between a upper or top voltage bar or 'rail.
 
On the bottom of the chart you ususally see the ground level or rail....
 
To make schematic diagrams easier to understand if the distance to the upper voltage reference, source or rail sometimes you will see abbreviated shorter voltage and gnd connections, like with ops amps etc..
 
When bread-boarding the V+ is usually strung out of the top on the board and the V- or gnd reference is laid out along the bottom....so you have an upper rail and a lower ground rail...like railroad tracks....
 
Alex

 
Quote:

Power supply voltage outputs (which the op amps and so on receive) are commonly called rails. e.g. the +7V rail

Ah thank you for the explanations. That makes sense now.

 

[Bee inthe Attic]

How is the O2 with the Senn HD 600 ?
 
I ask because I'm currently powering my 600's with a Fiio E9, to which many write is the bare minimum of an amp one should use to power 600's. However, after reading the power specs, the O2 and E9 both have similar output into these 300 ohm cans.
 
Is the O2 not especially good with higher impedance cans like the 600's? Thanks.

 

[Satellite_6]

Quote:

How is the O2 with the Senn HD 600 ?
 
I ask because I'm currently powering my 600's with a Fiio E9, to which many write is the bare minimum of an amp one should use to power 600's. However, after reading the power specs, the O2 and E9 both have similar output into these 300 ohm cans.
 
Is the O2 not especially good with higher impedance cans like the 600's? Thanks.

Very good. 
 
No, I assume both amps have ample power and someone told you some BS about the HD 600's being extremely hard to drive. 

 

[TheGame21x]

Quote:

How is the O2 with the Senn HD 600 ?
 
I ask because I'm currently powering my 600's with a Fiio E9, to which many write is the bare minimum of an amp one should use to power 600's. However, after reading the power specs, the O2 and E9 both have similar output into these 300 ohm cans.
 
Is the O2 not especially good with higher impedance cans like the 600's? Thanks.

The O2 is excellent with the HD 600 in my opinion.

 

[mikeaj]

There are two issues:  (1) outputting enough power to make the headphones sound sufficiently loud and (2) sound quality.
 
The amount of power delivered determines the volume.  Both the O2 and E9 can drive the HD 600 way louder than what a normal person would listen to.  That said, if you're trying to listen to some classical recording with wide dynamic range (thus low average volume), at a very high volume, you need more power output than most portable sources and integrated amps can provide.  E9 was the cheapest desktop form-factor headphone amp with enough power to blow peoples' socks off for the HD 600 for a while (until the recent Schiit Magni).  Anyway, if you're not maxing out the E9, you wouldn't be maxing out the O2.
 
Different people have different opinions on sound quality, but if you look at what's going on electrically and acoustically, the differences between amplifiers really aren't that great.  (read: that was a big understatement)  Furthermore, HD 600 has high impedance, which makes it relatively easy to drive accurately, so differences between amplifiers are lower for this kind of easier load.
 
A lot of people tend to confuse power specs with sound quality or performance, even though in reality, they're not using but a small fraction of the power levels their big honking amps are capable of.  Or surely one needs a desktop amp for desktop headphones, right?  (actually no)
 
The E9 is not especially good with some lower-impedance cans—actually, more like some IEMs.  O2 and E9 both may not be powerful enough for the quietest, least sensitive headphones, if you want to listen at a loud volume.  Other than that, not much to say.

 

[miceblue]

Quote:

There are two issues:  (1) outputting enough power to make the headphones sound sufficiently loud and (2) sound quality.
 
The amount of power delivered determines the volume.  Both the O2 and E9 can drive the HD 600 way louder than what a normal person would listen to.  That said, if you're trying to listen to some classical recording with wide dynamic range (thus low average volume), at a very high volume, you need more power output than most portable sources and integrated amps can provide.  E9 was the cheapest desktop form-factor headphone amp with enough power to blow peoples' socks off for the HD 600 for a while (until the recent Schiit Magni).  Anyway, if you're not maxing out the E9, you wouldn't be maxing out the O2.
 
Different people have different opinions on sound quality, but if you look at what's going on electrically and acoustically, the differences between amplifiers really aren't that great.  (read: that was a big understatement)  Furthermore, HD 600 has high impedance, which makes it relatively easy to drive accurately, so differences between amplifiers are lower for this kind of easier load.
 
A lot of people tend to confuse power specs with sound quality or performance, even though in reality, they're not using but a small fraction of the power levels their big honking amps are capable of.  Or surely one needs a desktop amp for desktop headphones, right?  (actually no)
 
The E9 is not especially good with some lower-impedance cans—actually, more like some IEMs.  O2 and E9 both may not be powerful enough for the quietest, least sensitive headphones, if you want to listen at a loud volume.  Other than that, not much to say.

While on the topic of high impedance headphones, though not really related to the O2, why do such headphones exist? I mean the DT880 comes in a whopping 600-ohm version....what benefits do higher impedance headphones offer other than having an amp's output impedance being negligible for the "magic" Z_load/Z_source value being greater or equal to 8?

 

[Bee inthe Attic]

Quote:

There are two issues:  (1) outputting enough power to make the headphones sound sufficiently loud and (2) sound quality.
 
The amount of power delivered determines the volume.  Both the O2 and E9 can drive the HD 600 way louder than what a normal person would listen to.  That said, if you're trying to listen to some classical recording with wide dynamic range (thus low average volume), at a very high volume, you need more power output than most portable sources and integrated amps can provide.  E9 was the cheapest desktop form-factor headphone amp with enough power to blow peoples' socks off for the HD 600 for a while (until the recent Schiit Magni).  Anyway, if you're not maxing out the E9, you wouldn't be maxing out the O2.
 
Different people have different opinions on sound quality, but if you look at what's going on electrically and acoustically, the differences between amplifiers really aren't that great.  (read: that was a big understatement)  Furthermore, HD 600 has high impedance, which makes it relatively easy to drive accurately, so differences between amplifiers are lower for this kind of easier load.
 
A lot of people tend to confuse power specs with sound quality or performance, even though in reality, they're not using but a small fraction of the power levels their big honking amps are capable of.  Or surely one needs a desktop amp for desktop headphones, right?  (actually no)
 
The E9 is not especially good with some lower-impedance cans—actually, more like some IEMs.  O2 and E9 both may not be powerful enough for the quietest, least sensitive headphones, if you want to listen at a loud volume.  Other than that, not much to say.

 
The E9 is terrible with most lower impedance cans I've tried it with.... renders the bass far to boomy (due to the 10 ohm headphone jack output).
But with higher impedance cans like the HD 600, I'm wondering if there is much difference between the E9 & O2. Is there a noticeable sound quality difference to justify dropping $150?
 
I want to get the most out of my 600's, and I often read on here that they don't sing with the E9. Do they sing with the O2?

 

[MrMateoHead]

They will sing with the O2. The O2 is a good amp.
 
Don't forget - other than power, output impedance, and flat response, amps like the O2 have a handy gain switch. In a High Dynamic Range recording (like with Gershwin Rhapsody in Blue), you'd be turning the volume knob way more than normal. Without enough power, this recording might not be loud enough for you. But with gain switched to 6.5X, you get more "volume" sooner from the amp. Gain is not really a substitute for power, but it comes in handy with a weak source, or sometimes really High Dynamic Range Recordings.
 
With the O2/ODAC, the nice part is that noise levels are still surpressed, as in, totally black. The only risk is with clipping. But with a good recording, this hasn't been an issue. And clipping would mean I was blowing my eardrums anyway.

 

[Satellite_6]

You can't use the high gain with a desktop source, however you will never need to with the HD 600.

 

[cel4145]

553-WAU16-400


WAU16-400


120 to 16VAC 0.4A

If it makes you feel any better having to wait on your power source, my O2 came yesterday from JDS Labs, and the power source didn't work. Stuck in Duracell land for a couple of days

 

[Bananaheadlin]

I got the WAU16-400 too, it seemed like the preferred alternative (upgrade).

 

[kskwerl]

Quote:

I got the WAU16-400 too, it seemed like the preferred alternative (upgrade).

Glad to here it

 

[adydula]

the hd600's will "sing" with the O2.....
 
gosh....
 
Alex