Effect of Amp on the CPU noise of the Clip+

[Timar]

I've just made a strage observation concerning the CPU noise of my Clip+...
On startup my RB'ed Clip+ makes some rather annoying, swirling, hf CPU noise as long as the disk icon is constantly active (about a minute). I suppose it is caused by the auto database refresh feature and the busy SD access it generates. It is very noticable even during playback at moderate volume levels. However, when using my FiiO E5 again, I noticed that this noise had completely vanished - at about the same overall volume level of course. Only when I crank the volume on the FiiO up to the maximum it becomes noticeable again but still much less than on the Clip+ at normal level. Isn't that strange? How could the FiiO possibly reduce that kind of noise?

[CrowdAds]

[AaronDude]

I don't know but I notice similar things with other equipment. The extra noise from my portable coby dvd player for example is lessened by a lot the more things I connect to the headphone jack but it's still noisey and crappy. And my creative speakers connected to the headphone jack of my laptop gets rid of any noise, I just plug in headphones to the jack of the speakers and everything sounds better to me.

[saratoga]

Originally Posted by Timar

How could the FiiO possibly reduce that kind of noise?

Are you running the Clip+ at the same volume in rockbox (e.g. comparing 0dB in RB to 0dB with the Fiio)?

[Timar]

Originally Posted by saratoga

Are you running the Clip+ at the same volume in rockbox (e.g. comparing 0dB in RB to 0dB with the Fiio)?

I run it at even higher volume (I always set it to 0 when connecting it to the FiiO).

[saratoga]

Originally Posted by Timar

I run it at even higher volume (I always set it to 0 when connecting it to the FiiO).

Well that explains it. If you boost the level of the audio above the level of the noise, you'll find that the level of the audio is higher then the noise

[Timar]

Ehm... you're right. I haven't thought of the possibility that the noise isn't amplified. But it isn't indeed. So this is really an advantage of using an amp.

[jjrosaria]

I don't know if this is the same case but this happens to my sony walkman as well.. But mine makes a high frequency sound while the screen is still turned on (eg when you switch songs and the screen turns on you could hear the HF sound)

[saratoga]

Originally Posted by Timar

Ehm... you're right. I haven't thought of the possibility that the noise isn't amplified. But it isn't indeed. So this is really an advantage of using an amp.

Ironically, you're using the amp to reduce the amplification

An inline volume control or an impedance adapter will work too. Basically anything that makes the headphones a bit quieter.

[rickysio]

Originally Posted by jjrosaria

I don't know if this is the same case but this happens to my sony walkman as well.. But mine makes a high frequency sound while the screen is still turned on (eg when you switch songs and the screen turns on you could hear the HF sound)

That's a lack of RF shielding, not CPU noise. If you must, place some sheets of aluminium foil between the PCB and the screen (do this only when the warranty is over and you're confident of your tech ability), it should alleviate the sound.

[WalkGood]

Originally Posted by rickysio

That's a lack of RF shielding, not CPU noise. If you must, place some sheets of aluminium foil between the PCB and the screen (do this only when the warranty is over and you're confident of your tech ability), it should alleviate the sound.

I thought this is why SanDisk used a metal plate shielding the circuitry from interference on the original design of the Clip, unless they’ve removed it in the newer “+” version I don’t see any added benefit from adding foil. Rather than your suggestion I would recommend an impedance adapter or a portable amp as saratoga has already suggested, less risk as a recommendation to others.