Headphone enthusiast thread! - Page 23

On December 10 2010 03:55 Myrmidon wrote:


A note first about most audio-DG products: you say that your Koss KSC35 sounds better using one, so a good DAC must make a big difference.

As they advertise, their DACs are supposed to color the sound, i.e. make it different from the original by intentionally adding certain distortions, maybe doing some EQ too as well. Who knows. (They do sell some DACs that are supposed to be less colored, but I don't know the specifics or the extent of what they're doing.) Therefore, it's not at all surprising that your KSC35 would sound different with them, and probably better--if that distorted sound is your preference.

It's the same idea behind tube amps. In theory, they are supposed to distort in ways that are pleasing. Mostly, it's adding extra harmonic content (2nd, 3rd, 4th, etc. above the fundamental, and things like that) to the original signal, which creates a fuller or warmer sound, to most peoples' ears. Actually, this is similar in some fashion to an organ with all its stops.

There are many different ways to distort the sound intentionally or unintentionally. When you're looking for what sounds the "best", that's hard to define since that will be different for each person. What is a good DAC? One that sounds the best, or one that produces the cleanest output, closest to the source material?

The former is hard to define, while the latter is simpler to measure. Standard audio measurements are just measures of the distortion, i.e. the difference between the output and the input. Usually these tests are done with pretty simple inputs, like a sine wave at a single frequency.
+ Show Spoiler [about distortion measures] +
So I wonder benefit a discrete DAC device has over the DAC section of a sound card. The high-end DAC chips likewise have high specs for SNR, THD, etc. like the op amps we're looking at. Both the DAC section in a high-end sound card and a discrete DAC device may use the same DAC chip. The discrete DAC device may just have better EMI shielding or isolation (does this matter, unless stray radiation is actually a problem?), better power supply filtering, and a nicer-looking case. The circuits are going to be pretty much what's on a sound card. What else am I missing?

And you'll notice all these devices have a power supply rejection ratio of like 100 dB. If you've got 50 mV peak-to-peak ripple on your supply rail for your DAC or op amps on a sound card, this means something like 500 nV peak-to-peak noise induced by the power supply on a sound card, which is not only way way below the threshold of hearing, but below the other noise in the system. Do you need super-duper power supply filtering on a discrete DAC device to get 8 mV peak-to-peak ripple on your supply rail, so you can have 80 nV peak-to-peak noise from the power supply noise?

Yes, there are a few small assumptions or details I'm glossing over, which is the point. I'm interested in hearing which parts actually make a difference.

edit: I actually wrote this post before I saw your last one about sound cards vs. DACs good timing?

edit2: Just to give a reference point for noise figures, let's assume you are listening at an output level of 1V (pretty loud--this would be at or above 100 dB SPL on most headphones). Let's assume our output listening level is 100 dB then, though it will depend on that input level and the headphones in question. 1 uV = 1000 nV of noise would give you a SNR of 10^6 = 120 dB. The noise would be 100 - 120 = -20 dB, where 0 dB is the threshold of human hearing. This is why I questioned the power supply requirements earlier. Even if you have only 80-90 dB power supply rejection ratio (PSRR), that's still plenty enough without worrying about getting the cleanest possible power supply rails. Most high-end audio op amps seem to be specified around a noise level of 1-5 uV in the audio range.

On December 10 2010 19:39 zak wrote:
Can someone tell me what headphone the guys in the GSL are using? They look like Sonys. Does anyone know for sure? Really appreciate it!

On December 10 2010 06:12 hifriend wrote:
Does anyone have any experience with the ATH-M50's especially for EDM, house, electro and such?

On December 10 2010 09:54 hifriend wrote:

Fuck it just placed the order, $242. Hope I like em.

On December 10 2010 09:54 hifriend wrote:

Fuck it just placed the order, $242. Hope I like em.

On December 10 2010 06:12 hifriend wrote:
Does anyone have any experience with the ATH-M50's especially for EDM, house, electro and such?