CD vs FLAC stored on flash drive vs streaming

As usual, depends. The better your CD playback equip. is, the better it will sound. A decent streamer and a great DAC will sound better than most CDP’s <$1K.
Great streamer usually doesn’t sound as good as a great CDT into the same DAC.
Absolute questions around here are deficient.

The only general "rule" in audio is that if it sounds better it is. Knowing what "should" sound better to you doesn’t mean it will.

That's generally what I've heard. My assumption is that the digital file via a CD player or via a flash drive has a shorter signal path to traverse and thus less chance to pick up analog noise along the way compared to the longer signal path that the streaming signal takes. Noise might include common-mode noise such as RF interference or  and differential-mode noise as typically caused by ground currents.

I have come to accept, "sounds good enough to be enjoyable" as my end point.  I cannot reliably determine a difference between my ripped CDs that are stored in my server's SSD and the same tunes played through Tidal (non MQA).  I get more of a noticeable change from a cable swap.  Once I reached the current level of digital playback equipment that I have, the convenience of having no physical media outweighed any small sonic differences.  I do plan to try Qobuz soon and look forward to hearing if there are significant sonic differences between that and Tidal.

At least with my system, I've found that the original source material largely rules.

Most of CDPs operate in real time.  For short scratches along the track (shorter than 4mm) they supply data from error correction.  For 4-8mm they interpolate lost data and above that they lose data (gaps).  Ripping is not real time process.  Computer can read each sector infinite number of times to obtain proper checksum.  I placed the limit of 200 attempts.  Theoretically ripped CDs should sound same or better than original, but for most CDs in decent condition it would be very difficult to hear the difference.  Connection to DAC or preamp is different story.  

All true. Copied CDs usually DO sound better than the mass produced originals especially on gold. I rip all CDs for convenience and with my playback setup I cannot ascertain any difference, except maybe the BluNode.

Copied CDs usually DO sound better than the mass produced originals

Sorry no they don’t, there far more error correction going on with burnt CD’s

The picture below is is of the 1’s and 0’ pits using a micron camera, and shows the
Retail Stamped Aluminum CD vs Gold layer burnt CD vs Aluminum burnt CD.
https://ibb.co/vYN4Dnc
As you can see the stamped is far better to read for lasers with minimal errors.

Cheers George

It appears that these pictures show physical burn to gold or aluminum layer. CD-Rs have  photosensitive dye - there is no physical burning.  CD-Rs can be written at speeds up to 52x.  Reading at 1x should be fine, otherwise we would have huge problem with data CD-Rs.  Even if lands are not perfect and produce some jitter it goes thru the buffer.  It is possible to output data at exact time intervals, since data stream rate is based on the same crystal clock.

The first retail stamped cd will have some error correcting, this substitutes the unreadable pit for what came before it be it 0 or 1, so it has a 50% of getting it right.
Every copied cd has the same each way bet with that original error, and then it has it’s own now to contend with also that the original didn’t, and so on and so on. The more you copy the original the more the errors grow and each one only has 50% of getting it right.

Pick up an original German first release of Propagander "A Secret Wish" it has the on the back from Sony the stamping errors with corrections that happen and at what seconds in each track.

Cheers George

georgehifi

The first retail stamped cd will have some error correcting, this substitutes the unreadable pit for what came before it be it 0 or 1, so it has a 50% of getting it right.

Not likely. The compact disk system has redundancies built into it. A single unreadable pit doesn't cause an error.

Error in CD reading  can be corrected by going multiple times over the same sector.  CDP cannot do that working in real time (reading only once).  That way CD-R copy can be better than original CD.  I was able to repair couple of unreadable CD by copying them to CD-R.  It took long time (couple of hours for one CD) but got recovered working copies.

I was able to repair couple of unreadable CD by copying them to CD-R. It took long time (couple of hours for one CD) but got recovered working copies.

The opposite with me with original retail ones, the more they were burnt the worse the sound got.
Proved it many times when hearing a loved CD at a friends, borrowing, it to burn <4x, then later getting the retail one used same version and it sounds better 

But burnt ones that wouldn’t even read TOC were readable using another brand blanks.
The more they were burnt the worse the got, then there’s the burnt ones that are unplayable unless certain blanks were used, but perfectly fine with every retail cd.

It depends how you burn them.  Often people burn CD-Rs at 2x or 4x nor realizing, that laser is too strong at this these speeds.  I might be wrong, but I believe that at the beginning it was just physical burn of metalic layer.  Now, it is only high sensitivity photosensitive dye.  Every CD-R has training track for laser power adjustment, but it has limitations.  Photo dye, that can be written at 52x might be overburned at 2x or 4x, in spite of laser adjustments.   

It all depends on personal experience - I've used Taiyo Yuden CD-Rs with phthalocyanine dye with good results, but he best for me is memory storage - easy to use, good sound quality (with proper connection) and ability to create back-up copy (or multiple copies).

I've used Taiyo Yuden CD-Rs

They were all I ever used, but you have to watch out, because many being sold are fakes, then found other ones just as good.

Now I don't bother with copying just get the original retail uncompressed versions if any, and used if need be, as to me they are better.

If you with flash drives include hard drives my guess is that they sound the best. Less risk for error correction and timing problems. SSDs are really fast and proven to work. 

Drawback of SSD is limited number of write cycles. They increased it greatly, but at the same time introduced new architectures, like "quad cell" - where writing to one cell causes writing to four. It is not a big problem (nothing lasts forever) and no problem for music storage. It is perfect application for SSD (constant reading, very little writing).