[mikeaj]

Running the signal through an amp twice will reduce the clarity of the sound. Imperfect analogy, but think of talking to someone through a cell phone that doesn't have a person on the other end but is simply the voice from another cell phone with a person on that end! The quality is going to get worse the number of cell phones are in the chain. Similar with amping. Double amping is reduplicating the effort without any gain...except loudness (provided your lamp isn't loud enough). Why not amp through 3 or 4 amps? The sound just gets degraded the more times it is amped.

Well yeah, it depends on the products involved, but with modern electronics, high-fidelity amplifiers driving an easy load (another amplifier at some thousands of ohms input impedance) shouldn't really have trouble and degrade the sound by any substantial amount. The effect of the last amp driving the headphones should dominate all the others, by far, particularly for lower-impedance headphones. Of course you want to avoid it if you can, but the point, as I said earlier, was that it's usually not a big deal. In many cases the difference is probably trivial enough to not be audible, unless the noise floor get raised high enough.

Actually here we're just talking about some kind of output stage buffer to drive headphones—except actually I don't think the Juli@ has one?

See here that after double amping, performance improves significantly, because the second amp is better than the first one (the one integrated in the sound card):
http://www.head-fi.org/t/568705/review-nwavguys-o2-diy-amplifier/1080#post_8150435

 

[chrislangley4253]

Mike beat me 

 

[LizardKing1]

This is pretty off-topic, but I hate creating new threads and this one is the best option, so I'll vent here. I don't think Steve Guttenberg knows what objectivists want/believe in:                     Source
 
 

The objectivists want to believe the most accurate playback system is always the best approach, but that view ignores the sonic variability of recordings and the sound preferences in play.

Right you are, Steve, if you mean using a flat response in the entire audio chain. But that's not what most necessarily objectivists believe in. Coloring is perfectly understandable from an enjoyable viewpoint. We all know that 'natural' doesn't directly equate with 'neutral'. An objectivist can love a Pro 900 or a XB1000. But playing a sinergy game along your audio chain to get your specific sound signature is pretty unnecessary, not to mention very expensive. It would be best to have a linear chain all the way up to the last element, choose that element based on the sonic characteristics you want, and if it still isn't close enough then use an EQ. 
 
 

If most of the music you like sounds like crap, hearing it "accurately" might not be the best way to go.

If there is war in the world, watching the news might not be the best way to go. I never understood the concept of using forgiving headphones with badly recorded music. Instead of just crappy music you also get crappy transducers. I guess audio is the only place where 2 wrongs make a right 

 but even if you're going to do this, using the last element in the chain to 'dumb down' your bad music might be smarter than a set of bad DAC, bad amp and bad headphones.
 
 

The Beats by Dr. Dre may have thumpy bass in your quiet living room, but the bass can sound surprisingly well balanced when you're groovin' to your favorite tunes in the New York City subway.

How much is your soul worth, Steve?
 
 

I'm no scientist, but it's weird that blind testing mostly proves there are no differences even when two products are very different. Blind testers can't reliably tell the difference between coffee and tea. The audio guys who steadfastly believe in blind testing have it easy, they can buy the cheapest crap and live happily ever after!

You're right! Blind testers are just stupid. If under blind testing people can't hear a difference, it's because people become stupider under ABX conditions, it's obviously not because there's no audible difference. It makes so much more sense to buy stuff that you can't tell apart from some "cheapest crap". Those sneaky blind testers!
Ok I failed. I can't make fun of this quote enough to even come close to explain how wrong it is. I guess music isn't the only thing being 'dumbed down' after all.

 

[proton007]

@LizardKing,
While I agree with you, I think we should not ignore the fact (please correct me if I'm wrong) that Steve G. has a background in selling audiophile equipment, and when it comes to selling stuff, we're mostly talking about creating a subjective experience for the customer that brings in a lot of hear/say and 'experience it yourself' kinda stuff.
Honestly, I don't really think he knows what he wants. Objectivists can make an informed purchase, such that they evaluate their listening preferences and buy the right equipment, no more, no less, because they know for sure what contributes to that difference apart from their brain.
 
PS: Is he really being serious when he says blind testers cannot distinguish coffee and tea? And what determines the price of any equipment? Whatever you can sell it for, of course. So saying that cheap stuff is *crap* speaks a lot for his bias.

 

[LizardKing1]

I never put subjective reviews aside. I like reading subjective reviews for the O2. I'll buy a new IEM in the next few months and I made my research based mostly on subjective impressions. The reason is because I can't completely correlate how something measures with how it sounds. And some stuff just can't be measured: if a pair of IEM has a weird shape (Monoprice 8320), it will give you a bad seal, completely eliminating the lower frequencies. So subjective is more practical.
 
Yes, he's a very experienced reviewer. He's probably heard all of the setups we consider to be the best of the best. But he dismisses objective evaluations based on wrong assumptions, like "all objectivists want ruler-flat setups" - it's not true, we believe in coloring, just in a more effective and cheap way that doesn't involve using amps and DACs as hardware equalizers.
 
I'm still trying to make sense of his objections to blind ABX.

 

[maverickronin]

Quote:

I'm still trying to make sense of his objections to blind ABX.

 
It obviously goes against his religious beliefs...
 

 

[imackler]

I can't even pretend to understand this! But I'm quite fine with being wrong... I probably don't understand this stuff/know enough to comment.
Quote:

Well yeah, it depends on the products involved, but with modern electronics, high-fidelity amplifiers driving an easy load (another amplifier at some thousands of ohms input impedance) shouldn't really have trouble and degrade the sound by any substantial amount. The effect of the last amp driving the headphones should dominate all the others, by far, particularly for lower-impedance headphones. Of course you want to avoid it if you can, but the point, as I said earlier, was that it's usually not a big deal. In many cases the difference is probably trivial enough to not be audible, unless the noise floor get raised high enough.
Actually here we're just talking about some kind of output stage buffer to drive headphones—except actually I don't think the Juli@ has one?
See here that after double amping, performance improves significantly, because the second amp is better than the first one (the one integrated in the sound card):
http://www.head-fi.org/t/568705/review-nwavguys-o2-diy-amplifier/1080#post_8150435

 

[chrislangley4253]

Quote:

I can't even pretend to understand this! But I'm quite fine with being wrong... I probably don't understand this stuff/know enough to comment.

just know, double amping isn't bad at all, in most circumstances.. Avoid it when possible, of course. But don't choose no amp over double amping, if you need an amp

 

[DarkSleip]

Quote:

I never put subjective reviews aside. I like reading subjective reviews for the O2. I'll buy a new IEM in the next few months and I made my research based mostly on subjective impressions. The reason is because I can't completely correlate how something measures with how it sounds. And some stuff just can't be measured: if a pair of IEM has a weird shape (Monoprice 8320), it will give you a bad seal, completely eliminating the lower frequencies. So subjective is more practical.
 
Yes, he's a very experienced reviewer. He's probably heard all of the setups we consider to be the best of the best. But he dismisses objective evaluations based on wrong assumptions, like "all objectivists want ruler-flat setups" - it's not true, we believe in coloring, just in a more effective and cheap way that doesn't involve using amps and DACs as hardware equalizers.
 
I'm still trying to make sense of his objections to blind ABX.

The problem is that audiophiles with money get expensive phones', and in some cases they are too hi-fi for them, so they search for a low-fi expensive item to put in the chain, as getting lower-fi headphones would be "unthinkable" or "ridiculous". On some other cases, that are more common, they just simply can't believe that a piece of gear of that quality is more than well fed with a 100$ amp,, then there's bias and *poof* they just got an expensive piece of gear that sounds practically the same (if it is measurably true to the regional sound).
As for what you say about subjective reviews, I only really trust them when they are about headphones, as they have much more complications. With a DAC you mostly got to deal with ENOB, jitter and overall distortion; none of which is that hard to deal with, so you can get audible transparency without spending more than 100$. With an amp you got THD and IMD, which are a part of that overall distortion, but they are still not too hard to mute. With headphones you goat a whole new world of things that change the experience, as they have more interaction with physics, you have to avoid the sound bouncing around the air chamber so it doesn't generate extra distortion, you have to make a perfectly put in place diaphragm that doesn't significantly damp certain frequencies, and I could go over a ton of other things, but I hope you get the point.

 

[haejuk]

Can anyone tell me why I get some clipping with my O2 when I use an LOD with my 3rd gen iPod Touch?  It sounds perfectly fine when I feed it the line out signal from my DAC (1.7v RMS), but I get low frequency clipping or distortion with the iPod, which I am 90% sure is a lower voltage signal.  Anyone know why?  Or better yet, have any solutions?  I get the clipping at 1x gain and 2.5x gain.  I haven't tried any other gain options.

 

[mikeaj]

Quote:

Can anyone tell me why I get some clipping with my O2 when I use an LOD with my 3rd gen iPod Touch?  It sounds perfectly fine when I feed it the line out signal from my DAC (1.7v RMS), but I get low frequency clipping or distortion with the iPod, which I am 90% sure is a lower voltage signal.  Anyone know why?  Or better yet, have any solutions?  I get the clipping at 1x gain and 2.5x gain.  I haven't tried any other gain options.

 
iPod LOD gives 0.5V I think.  The headphone output is more like 1V?  Maybe it depends on the model.  Anyway, you're right that it should be no larger than the signal sent by the DAC, and certainly it shouldn't be causing clipping with 1x or 2.5x gain, even on batteries.  If any amp can handle the signal from the DAC, it should be able to handle the signal from an iPod.
 
Have you tried making sure all EQ was turned off?  Did you try the headphone output?  Did you try the exact same setup and test tracks as with the DAC?
 
For confirmation, you can also try playing problematic music through the iPod and O2 and record the output with a computer sound card (integrated or not).  You can do that in something like Audacity (free software) and look at the waveform there to see if it's clipped or not.  Open up the original track's waveform for comparison.

 

[haejuk]

I am 100% sure it is something with my iPod.  I will try turning EQ off in my iPod, but when listening to the same source file from my DAC, I had the bass EQ'd way up and didn't experience any clipping.  I am also wondering if there is maybe something wrong with my super cheap iPod LOD cable.  I already planned on making myself a new one, so I will be able to test that soon as well.  As a last resort I will hook it up to my soundcard and check the waveforms to see if it is actually clipping or just distortion.

 

[LizardKing1]

I'm more inclined to believe your iPod's EQ just sucks more than your computer EQ.

 

[haejuk]

If it was the iPod's EQ I would expect to hear the same distortion/clipping when listening through the headphone out, correct?  When I plug in my IEMs directly to the headphone out, it sounds fine.  Maybe there is just a problem with my iPod's line out.

 

[mikeaj]

iPod EQ is well known to be able to cause clipping.
 
The problem with any EQ is that if you're boosting frequencies without lowering the gain digitally to compensate, you can have the audio exceed 0 dBFS (the maximum).  All of those values will get chopped to 0 dBFS, so you get clipping.  Out of the headphone output, you may not be using full volume, so that will attenuate back some boost you set with EQ, so everything is shy of 0 dBFS.  Out of the line out, it should be at max volume, so there's no attenuation to save you.
 
Most software EQ implementations that aren't bad will automatically reduce the level to avoid clipping, if you're boosting frequencies.  Or you could just be not using 100% volume on the computer?
 
The alternative is to just use EQ to turn down the volume of all the frequencies but the ones you want to boost.