sgrossklass
Headphoneus Supremus
- Joined
- Dec 3, 2004
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Quote:
Err... not quite. Assuming sensitivity per 1 mW of input power to be constant (e.g. 97 dB for the HD580), higher impedance means that a higher voltage swing is needed to drive cans, while the current requirements will be lower. Thus lower-impedance cans are better suited for portable devices operating off very finite operating voltages, at the downside of either requiring very large output coupling capacitors or a DC coupled output. Additionally, if you have an unbuffered opamp based amp (e.g. Cmoy), the opamp will struggle harder with lower-impedance loads, and output series resistors to keep cable capacitance off the amp will have more of an influence. (47 ohms are not significant with 300 ohm cans, but will have a noticeable influence on 50 ohm ones.) The Revo 5.1 has 5 ohms of output resistance on the headphone out, and with 50 ohm cans this would require 100µF, better 220µF output coupling caps for good bass response (and if you wanted to design for a cutoff freq of ~2 Hz to get rid off 'lytics nastiness, you'd need 1500µF caps - yikes), while with 300 ohm cans 47µF (220µF) would be fine. IMO the current HD5x5s and such are too low in impedance for home cans already.
Quote:
The 580 has the reputation of being fairly amp dependent and not really being worth it without one. However, a Revo 5.1 should drive it about as well as your average Cmoy, so I don't see why one shouldn't give it a spin. And then you still have quite a bit of scaling potential left, and you can even upgrade the grilles (to HD600 ones) and cables (try the HD650 one for a start).
Originally Posted by JaGWiRE I don't know why you guys are suggesting me 555's. I'm looking to spend some serious cash, for a pair that'll last me a few years, I still really like the 580. I am beginning to guess that resistance is for bass, and the higher the resistance, the more bass to expect. |
Err... not quite. Assuming sensitivity per 1 mW of input power to be constant (e.g. 97 dB for the HD580), higher impedance means that a higher voltage swing is needed to drive cans, while the current requirements will be lower. Thus lower-impedance cans are better suited for portable devices operating off very finite operating voltages, at the downside of either requiring very large output coupling capacitors or a DC coupled output. Additionally, if you have an unbuffered opamp based amp (e.g. Cmoy), the opamp will struggle harder with lower-impedance loads, and output series resistors to keep cable capacitance off the amp will have more of an influence. (47 ohms are not significant with 300 ohm cans, but will have a noticeable influence on 50 ohm ones.) The Revo 5.1 has 5 ohms of output resistance on the headphone out, and with 50 ohm cans this would require 100µF, better 220µF output coupling caps for good bass response (and if you wanted to design for a cutoff freq of ~2 Hz to get rid off 'lytics nastiness, you'd need 1500µF caps - yikes), while with 300 ohm cans 47µF (220µF) would be fine. IMO the current HD5x5s and such are too low in impedance for home cans already.
Quote:
I really like the look of the 580, but none of you have suggested it, yet on the other parts of the forums they are really popular. Let me rephrase my question, what advantages do your headphone suggestions have over the 580, and what are the downers to the 580? |
The 580 has the reputation of being fairly amp dependent and not really being worth it without one. However, a Revo 5.1 should drive it about as well as your average Cmoy, so I don't see why one shouldn't give it a spin. And then you still have quite a bit of scaling potential left, and you can even upgrade the grilles (to HD600 ones) and cables (try the HD650 one for a start).