ZBoneCapone
New Head-Fier
- Joined
- Jul 22, 2013
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When do I need one and why? I've read that a DAC really won't alter sound and that amps are only needed if you want more volume. Could someone explain these things to me?
DACs do not drive headphones directly (though if you plugged one in it would make sound). They output line level signal which must be fed into another power amplifier (headphone amp, preamp + power amp, integrated amp) to get a signal strong enough to properly drive sound equipment. There are DAC/amp-in-one products, such as some sound cards (Xonar Essence), and some external DAC/amp combos. Give us a budget and we can give you better recommendations.
I know what a DAC actually is, I know that it converts digital to analog. I want to know when and why I need it. What type of headphones? How high of an impedance? Those sorts of things. I am going to be driving the AKG K702 65th Anni. edition
tube amps produce a warmer (more bass heavy sound) while solid state amps are flat and more neutral.
General rule for amps (as I've heard it, I don't know the science), is that high impedance headphones need high-voltage amps. Low impedance headphones need high current.
Ohm's Law is being applied here, I think: V = IR
. So when you pair an amp with a certain pair of cans if the cans are known to be bass heavy and you buy a tube amp then it will be bass heavy + bass heavy = terribly bass heavy so usually you want to put cans that lack bass with a tube amp to counter act the lack of warmth and vise versa for base heavy cans.
When do I need one and why? I've read that a DAC really won't alter sound and that amps are only needed if you want more volume. Could someone explain these things to me?
What, just completely ignore this section of the post.
Whether you need an amp depends on two things, the impedance (complex resistance) and sensitivity (think efficiency). Impedance is measured in Ohms ([size=small]Ω).[/size] Sensitivity is measured in dB/mV.
A headphone is adequately driven (which may not be necessary but most believe that a fully driven headphone is better sounding) when the volume reaches a certain level. 110 dB is a level that I've seen used for this type of measurements (don't listen to your music at this level, it is really loud). You need to supply the headphone with enough voltage (mV) to drive the volume (dB) to adequate levels.
The reason why build in sound cards/portable devices can't power high impedance or low sensitivity headphones is that they can't supply enough voltage at the impedance of the headphone. Most if not everything can supply more than enough voltage at low impedance. At higher impedance, most sources without a dedicated amp will struggle to supply the voltage.
Huh?