While using the FF2 at low volume, with and without earphones, there is a permanent ambient noise, interupted by high frequency bleeps. We noticed that one listening to audibooks. We tried different settings, different players, different audiobook-files, even with or without earphones, you can hear it. Only at low volume, but especially in a silent surrounding you can hear this noise also while listening to music via Spotify or files direct from your FF2.
Than we tested the second FF2, nice to have two of them, but the problem is there the same. With that bug we can not use the FF2 as a mp3-player …
Umfortuantely, I have the same behaviour with my FF2 as well. It’s quite a showstopper for me since I use my phone for listening to something in order to fall asleep nearly every day. I’m also afraid, that the cause of the problem is hardware related. Thus, a software fix might not be possible.
I’m experiencing this behaviour as well: I use FP2 as a music player, eg in the car connected via cable to AUX-in.
(BTW, FP2 seems to have a lower volume output than my previous phone.)
Especially between songs, but if I remember correctly also on very low volume sections during a song, there is a clearly audible hissing sound / noise.
Any idea for a possible workaround or improvement on this?
I have the same problem. I use the FP2 to listen to audiobooks or podcasts (also to fall asleep sometimes), and the hissing noise at a low volume is very annoying. I would be very glad if there was a solution or a workaround for this!
I do not own a Fairphone yet, but I am considering buying one once sailfish for FP2 is released. However, this is exactly the same issue that I’ve been having with my Jolla phone. I solved it by using an adapter for my earbuds:
http://www.etymotic.com/consumer/accessories/er4/er38-24.html
These came with my Etymotic ER4 earbuds, but the work fine with any other brand. Now, I suspect that the reason why they remove the noise is because they increase the impedence of the earbuds, so that the device needs to output a higher energy sound for the earbuds to react. The low level backround noise of the device itself is therefore removed completely. I also have some high impedence studio headphones, these don’t pick up the noise either.
This is probably due to poor shielding or something. I cannot think of a way of fixing it in software. High impedence earbuds should fix it though.
@Overmann, if I understand you correctly, using this equipment means that I would have to turn FP2’s volume louder in order to get the same sound level on my speakers - is this correct?
In this case, it might not really help me, because to me it seems that FP2 has a lower audio output level than my previous phone and when being in the car, I have the sound setto maximum output already.
To me it seems if FP2 plays a song with no sound (a “quiet song”), I don’t really hear that much.
But between songs, or about 1-2 seconds after pausing a playback, the noise gets on. As if the problem only occurs if no analog signal is processed. Could this somehow be the case?
Yes, correct, the device (and others like it) will reduce the output to the earbuds slightly. My stock Etymotics has an impedence of 27 Ohm, and the device (i think) increase that to 100 Ohm which is quite a lot. However, the Etymotic buds don’t pick up the noise from my Jolla, so IF I am correct in this then 27 Ohm, in jolla’s case, should be enough to eliminate the backround noise from the device. The other set of earbuds, nocs ns500 (that I use mainly for listening to audiobooks and podcasts when going to sleep) has an impedence of 16 Ohm. The noise is quite audible at low volumes when using these.
What earbuds are you using?
The issue you are describing with noise kicking in between songs is strange but sounds a bit like the noise that I hear when using the low impedence earbuds and recieving an e-mail or message. As the notification sound decays a static is heard quite clearly, as if the sound is very poorly compressed or something similar. These sounds are also inaudible when using higher impedence earbuds.
My 27 Ohm Etymotics plays quite loudly. 27 Ohm really isn’t all that much. It might be worth it to try the phone with some higher impedence buds or headphones just to see if that solves the issue. If it does, but you want ot kick the volume level up I think buyng a headphone amplifier is the only solution. It alone might solve the noise-problem AND it will let you increase the volume to unreasonable levels if you want to.
Please note: This is just an hypothesis. I am in no way an expert on this. I might be wrong with the whole impedence line of thinking.
I find a couple of solutions that you might want to check out:
Check out this link as well:
Now, there is no doubt that the problems stems from FP2 having a low quality audio output, but these might solve the issue.
@Overmann, many thanks for all your input! 
According to the different earbuds that you used, this might indeed help in my case as well.
To be honest, I don’t really know anything about hifi-related specs. It’s an interesting topic, but might take a little while for me to dive into it. Let’s see how fast the FP2 known issues are taken care of. Since most of the time, sound is ok, there are more pressing FP2-topics to me at the moment 
…
Concerning you question:
I’ve had my in-ear headphones for many years now, I cannot remember which product they are, sorry. Yet, I do not hear any of the noise on these headphones - even when turning the volume on too-high a level.
If I have the music on background-level, there’s just music anyway (no noise). Yet, as described, it seems that FP2 has a lower volume output than my previous device. If at times I turn the volume up, I hear the described noise between songs on both my Sony SRS-Z510 stereo speakers (small desktop speakers) as well as in my car (Aux-In linked to the default car radio, everything probably connected with rather low-quality cables).
BTW: a while again, I was thinking of buying a bluetooth hands-free kit for my car - this might qualify both as a workound AND a solution (for the car).