Are streamers digitally enhanced?

I originally asked this question hoping someone knew more factual information about how digital designers program chips to convert Internet packets to a PCM stream and, how that might affect the sound. I don't know whether chips are just built to do that off the shelf or whether a designer has some control over parameters. I'm not asking about magic, just electrical engineering. 

For the moment, I agree with @soix that the clock quality matters. I believe the differences I hear between my coax and USB input are due to the streamer having a better clock than my DAC. That will eventually change. 

Aside from those streamers that advertise DSP, I am with the crowd that says streamer sound is primarily affected by clocking and noise and no manipulation is occurring. The absence of noise and the use of a high quality clock makes all the difference. And while I can’t explain it, the cable to the DAC can have a significant effect as well.

Why are you asking electronic questions to audiophiles. Especially on the internet. You don’t need to learn this material. Sure some blow hard will chime in, “ I was an ee for 64 years before my retirement 30 years ago. It’s fine that you don’t know this. It’s probably best to keep it that way. Your device is awesome. So much thought went into it. A thousand things changed with your upgrade, not just one. Don’t worry about the math and just enjoy that pure signal. Peace yo

@mashif 

No, respectable and well-engineered streamers do not use DSP to "enhance" the sound, any more than a respectable speaker designer would seek to "enhance" the sound beyond producing something that reflects how he or she thinks a good speaker should reproduce music.  Adding DSP effects is your choice as an end user, but would be considered poor practice by a high-end streamer manufacturer.  

What your studio engineer friend cannot grasp is that there's a tremendous amount of science that goes into sending a digital signal from one place to another and getting it to your speakers in a form that resembles music.  I can only assume that he's never bothered to experiment with such things.  Even the basic software involved can change the sound, without getting anywhere near added DSP effects.  I have several different Raspberry Pi-based streamers.  Apart from the different mechanical designs of each streamer, a change in the base operating system employed can change the sound.  Roon, Volumio, Gentooplayer, Audiolinux, etc. can all sound different because of the transfer protocols and adjustments they make to the clocking, CPU, etc.  Power supplies, internal design and cabling, and so on, can all make a difference.

I recently pulled out a 1980 CD of John Lewis's "The Bridge Game" and was reminded of how far digital recordings themselves have come since then.  For the first time in a long time I heard that good ol' blanket of digital fog that afflicted so many early digital recordings, blunting the transients, smearing the instruments, placing a dirty grey plate-glass window between me and the musicians.  Presumably the engineers at Philips thought they were doing a wonderful job at the time, but it's a pity that such beautiful music is marred by such a dreary recording.

I'm also reminded of a listening session that took place some years ago.  My local audio club was hosting a USB cable shoot-out.  No less a designer than David Berning was in attendance.  He thought the whole idea was nonsense but after several hours he left shaking his head and muttering things like, "It can't be possible."

Your studio engineer friend is surely familiar with the work of Keith Johnson of Reference Recordings, who has spent decades improving and refining the recording process to produce legendarily beautiful LPs and CDs.  He didn't achieve that by shrugging off the differences in equipment as tricks or "enhancements." ;-)

Another important difference between streamers not mentioned thus far is operating systems employed. Various OS have potential to affect sound quality via optimization of hardware, this means optimization via minimizing noise and/or providing low latency, this means speed or efficiency of sending data packets. There are many technical explanations for why streamers don't all sound alike, read some white papers over at Audiophilesyle forum to educate yourself.