headfinoob
100+ Head-Fier
- Joined
- Jan 20, 2010
- Posts
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Hello fellow Head-Fi members,
The question: how well does the Galaxy S /w Voodoo (Voodoo'ed WM8994) compare to the iPod's line-out (primarily 5/5.5G and 7G) as a source for equipment with line-level inputs? I haven't been able to come to any concrete conclusions regarding the matter. I find that information regarding iPod measurements is convoluted in that in many cases, the particular iPod model is not specified.
I would like this thread to help others making similar choices come a well-educated decision. There are several factors that seem to come into play. For now I'd like to consider the scenario where the source will be connected to a typical line input, which I noticed on my gear and some other gear to be 200mV sensitivity and 47,000 ohms impedance.
DISCLAIMER: The information below may be incorrect, please correct me if they are found to be incorrect or misleading.
iPod 5/5.5G:
Line-out voltage: 1.0V RMS
Line-out impedance: approx. 100 ohms?
Galaxy S:
HP amp voltage: ?
HP amp power: 3mW RMS per channel (the spec sheet states: "6mW total power for DAC playback to headphones")
HP amp impedance: approx. 8 ohms?
IMPEDANCE:
Whether using and iPod or a Galaxy S, the output impedance is far, far less than the line-level input impedance of the receiver. This will mean that the connection is "bridged" and both the iPod and the Galaxy S will drive the receiver without being overloaded.
Are there issues with too low of output impedance on line-level equipment? I would assume that there is a reason line-level outputs are designed with impedance in the hundreds of ohms...
VOLTAGE:
I really should just measure my iPod and Galaxy S to determine the RMS voltage with a sinusoidal waveform referenced to 0dB so I can see the results myself. Considering the input sensitivity of our receiver is approximately 200mV (I am assuming an RMS value), then we should be able to drive the receiver outputs to full power as long as we are getting 200mV from the source. The iPod certainly meets that criteria with its 1.0V RMS output. I believe that the Galaxy S voltage will easily exceed 200mV.
I read that the iPod line output is distorted at 1.0V RMS and that 0.9V RMS is more realistic output voltage. It would be very interesting to see what voltage the Galaxy S would distort at as well as what voltage the Galaxy S distortion levels would be comparable to the iPod at 0.9V.
I would just like an apples to apples, or apples to voodoo (sorry), comparison to see which device would fair better as a source for line-level equipment. Perhaps the sound quality of the 5/5.5G iPod and the 7G iPod compared to the Galaxy S could theoretically be ignored. Part of me says that the iPod's line-level output should be better, but I'd like to put this matter to rest.
The question: how well does the Galaxy S /w Voodoo (Voodoo'ed WM8994) compare to the iPod's line-out (primarily 5/5.5G and 7G) as a source for equipment with line-level inputs? I haven't been able to come to any concrete conclusions regarding the matter. I find that information regarding iPod measurements is convoluted in that in many cases, the particular iPod model is not specified.
I would like this thread to help others making similar choices come a well-educated decision. There are several factors that seem to come into play. For now I'd like to consider the scenario where the source will be connected to a typical line input, which I noticed on my gear and some other gear to be 200mV sensitivity and 47,000 ohms impedance.
DISCLAIMER: The information below may be incorrect, please correct me if they are found to be incorrect or misleading.
iPod 5/5.5G:
Line-out voltage: 1.0V RMS
Line-out impedance: approx. 100 ohms?
Galaxy S:
HP amp voltage: ?
HP amp power: 3mW RMS per channel (the spec sheet states: "6mW total power for DAC playback to headphones")
HP amp impedance: approx. 8 ohms?
IMPEDANCE:
Whether using and iPod or a Galaxy S, the output impedance is far, far less than the line-level input impedance of the receiver. This will mean that the connection is "bridged" and both the iPod and the Galaxy S will drive the receiver without being overloaded.
Are there issues with too low of output impedance on line-level equipment? I would assume that there is a reason line-level outputs are designed with impedance in the hundreds of ohms...
VOLTAGE:
I really should just measure my iPod and Galaxy S to determine the RMS voltage with a sinusoidal waveform referenced to 0dB so I can see the results myself. Considering the input sensitivity of our receiver is approximately 200mV (I am assuming an RMS value), then we should be able to drive the receiver outputs to full power as long as we are getting 200mV from the source. The iPod certainly meets that criteria with its 1.0V RMS output. I believe that the Galaxy S voltage will easily exceed 200mV.
I read that the iPod line output is distorted at 1.0V RMS and that 0.9V RMS is more realistic output voltage. It would be very interesting to see what voltage the Galaxy S would distort at as well as what voltage the Galaxy S distortion levels would be comparable to the iPod at 0.9V.
I would just like an apples to apples, or apples to voodoo (sorry), comparison to see which device would fair better as a source for line-level equipment. Perhaps the sound quality of the 5/5.5G iPod and the 7G iPod compared to the Galaxy S could theoretically be ignored. Part of me says that the iPod's line-level output should be better, but I'd like to put this matter to rest.
