Bet you dollars to donuts you successfully capture the noise (not distortion) then.
I have all necessary equipment but a spare 3,5 mm socket at hand right now. So I cannot setup a loaded test without cutting my headphone cable. A splitter might accomplish the same without soldering. But are they always just connected in parallel without additional circuitry?
After reading several positive posts around here, I replaced my venerable iPod G5 Video with a little Sansa Clip+ and a 16GB flash card. Missing AAC support was a deal breaker, but Rockbox was reported to run fine.I must say, compared to the absolutely flawless experience with my last iPod, I'm quite dissatisfied. It started with a bug of Rockbox 3.7.1 that large SD cards are sometimes not initialized properly (and thus don't appear in the menu), which affected my Transcend model. An upgrade to the latest daily build fixed this.An issue, that I can't fix with whatever build, is annoying CPU noise. At the beginning of tracks and during rebuffering of longer tracks there is a short humming sound (like a bumblebee) mixed with a fast sequence of random high frequency tones. The sound differs as a function of data format and content. It is very homogeneous with WAV tracks (only humming) and different with lossy and lossless codecs. The same file encoded with FLAC and AAC leads to different short distortions. It is only audible for tracks with initial silence or very dynamic content, for example classical music with quiet passages or audio books. The original firmware does not show this behavior. It is probably a throttling issue. Rockbox just reads and decodes the file in a regular loop as fast as the CPU can deliver it. Due to cheap hardware design this leads to audible inference on the output. The original firmware probably works around this by some form of flow control and doesn't read the data any faster than required. But, as I've said, due to missing AAC support the original firmware is not an option.
Sansa implements gapless playback
It's obviously a problem with the Rockbox software. These kind of noises are the sort of thing that programmers who pay attenation to details isolate and fix. There's nohting faulty about the Clup+ CPU - it is yet another ARM processor, a processor that is used in zillions of products with well-written software that produces no extraneous noises. Rockbox seems to be a voluteer product, and that means that they fix what they want to fix, and don't fix whatever is too much trouble for them to fix.
I hope this gets fixed or Sansa implements gapless playback, otherwise no Clip+ for me. Does this happen with the non-plus version of a Rockboxed Fuze?
I'm guessing people who hear noise have bought their players more recently (IIRC the last revision showed up in July or so). Maybe they've changed something else.
For me the noise is related to SD access ... (maybe Sandisk changed the SD controller?).