iPod Video 30gb Sound Pollution

[Nimdok]

I am currently having a problem where there is a repetitive and very light noise which can be heard through the headphones. It's somewhat of a clicking and popping noise which is very light, but constant. It almost sounds like a mechanical sound, but it can only be heard reproduced through headphones.

I am running the most recent build of Rockbox as of today. The sound is not present when switched over to Apple's firmware. I have used two headphones, with the same result (a Sennheiser HD 595 and a Sennheiser HD 590). The sound becomes much more apparent when the headphone is also plugged into a headphone amp (I have a PA2V2) through a lineout (Turbodock II is used for the lineout). The sound is still present, however, when either headphone is simply plugged into the iPod's headphone jack. The sound continues to play during playback of a song, or when the firmware is just simply idling with nothing playing at all. My equalizer, crossfader, etc. are all turned off.

This sound is barely audible at usual listening levels, but can still be heard and is of course somewhat annoying because of that. When a song is playing, it's usually drowned out and not noticeable at all - but the moment there's a very quiet bit of the song (or nothing playing at all) you can hear it again. This makes it quite an annoyance, albeit livable.

I'm wondering if anyone else is experiencing this same problem, if it's a known bug and I just missed it somewhere, or if I'm alone. It seems to definitely be a Rockbox problem, as I don't hear it all in Apple's firmware or with different audio equipment.

Thank you for any help you may be able to provide!

[TexasRockbox]

I have read though have no listening proof of, that the high-end Sennheisres HD600, HD595 are difficult to use due to the high impedence drivers.

What file is being used -- I assume the same file (MP3, AAC) as the ipod firmware is being compared to.

Are the EQs and the Bass & Treble set to zero or off -- or whatever applies?

Does the same problem happen with the stock Apple earbuds (around 32ohms)?

[linuxstb]

Is this the same problem that is described in the KNOWN_ISSUES files (in the .rockbox/docs directory on your player) and here?

http://www.rockbox.org/tracker/task/4937

[TexasRockbox]

I too can confirm the continued presense of the defect.

Would this information abou i2C be of any help:

http://www.esacademy.com/faq/i2c/general/i2cspecver.htm

[Nimdok]

Is this the same problem that is described in the KNOWN_ISSUES files (in the .rockbox/docs directory on your player) and here?

http://www.rockbox.org/tracker/task/4937

Ah yes, that certainly seems to fit the description of my problem. However, it seems that a file doesn't even need to be open for playback - as long as Rockbox is on it is there.

Anyway, good to know the problem is already known and isn't just me. I hope you find the issue soon! Thanks for the help.