Motherboard marketing BS (audiophool warning + extras)

[ivan747]

Who says high quality audio is only available on high-end motherboards? ASRock applied ELNA audio capacitors on mainstream and entry-level motherboards! Compared with traditional solid caps, the leakage current of ELNA audio caps is merely 3uA. This is the key to reduce noise level significantly and satisfy even the pickiest audiophiles.

Ignoring the audiophiles, how can the leakage current (a DC characteristic) affect the noise level (an inherently AC phenomenon)?

Bullshit aside, I'd like to know how good quality capacitors can really affect the sound output of any audio device.
Of course, this electrolytic capacitors are used to block DC from the DAC/amplifier inside the product in question. In other words, these capacitors and the headphones connected to them (or line-in circuits) form a high pass filter. The single most sound-affecting characteristic of this circuit is the high pass filter stop band, the point where it starts to attenuate low frequencies significantly. I assume you could even ruin a product if you were on a budget and designed your product to use high quality caps, but the budget forced you to use a capacitance too low for the ideal stop frequency (<20Hz).

How can audio quality actually be improved on similar products?

What do you think about these motherboard gimmicks? Even low end motherboards now feature these sort of gimicky electronics marketing. I also saw low ESR MOSFETs being featured for their high ESD immunity. These were probably used as pass elements for the RAM DC-DC converter. It was very carefully worded to make it seem like this ESD protection somehow protected the RAM:

The next generation NexFET MOSFETs control the power supply to DRAM slots more efficiently. They provide lower RDS(on) 2.9 m ohm, delivering higher efficiency and lower temperature.

NexFET MOSFETs in memory areas use a special design for protecting them from electrostatic discharge and offer up to 7.5 times the ESD protection levels compared to traditional MOSFETs.
* Human Body Mode.

First they talk about how the MOSFETS "control the power supply" and then go to talk of how they offer "up to 7.5 times the ESD protection levels". The "them" that is in bold is the only word that saves them. Basically they are marketing how good the RAM DC-DC converter MOSFETs are at protecting themselves... not the RAM, not the processor... LOOK THEY EVEN HAVE A GRAPH 

[German_EE]

No, I'm not an audiophile as I don't have the hearing now to justify it, but I can see how different capacitors can affect a circuit.

1) Capacitor leakage current is a factor in DAC and particularly ADC circuits. If a capacitor starts to leak then it might provide a DC offset on the ADC input, especially if the ADC input stage has a high impedance.

2) Different capacitors have a different frequency response, especially at the low and high ends of the audio spectrum. Note that I'm not saying that some are better, just different.

3) Poor quality ceramic capacitors are piezoelectric and the amount of capacitance that they provide can vary depending on the applied voltage. Good quality film capacitors do not show these characteristics.

4) Good quality capacitors have a low ESR.