After several trials I now have no doubt that the one and only speed at which this drive yields best results is 40X. And slower speeds actually return way more errors!

What I'd like to confirm at this point is whether this is a normal trait of this drive or is there something wrong with it ? Also I want to know if all Lite-Ons behave like this or is this a freak thing ?

Secondly, whenever a read error occurs the drive slows down. Is this controlled by the firmware ?
This drive is on firmware v.SS0E. I notice that it slows down to 8X whenever it encounters a read error. Is this a firmware feature ? And all Lite-Ons do that ? Or do I just have a messed up drive ?

My Liteon (SOHR-5239V) DAE quality is excellent if I use it EAC burst mode and I let it control the speed. That is to say it remains excellent even when its firmware slows down the speed. BTW this drive DAE was tested against Plextor Premium and PX-716A and they deemed to be much worse than this Liteon. However if I forced a reading speed, I got inferiour results. So forcing the speed did not yield good result.

My Sony CDU5221 is similar but not the same.

It does best with the speed set to 23.9X with speed reduction unchecked. This drive often does better with C2 enabled although C2 performance isn't anywhere near as good as other drives (like my PX-716A). Also, it is a non-caching drive and telling EAC that it caches almost certainly reduces the chances of getting an accurate rip from a bad disc. I mention these other two settings because I believe the improvement in accuracy may also be related to the extraction speed.

The offset of the CDU5221 isn't the same as Triza's SOHR-5239V, but it is the same as many other Lite-On drives.

Off-topic:
With some discs my Sony CDU5221 does a better job than my Plextor PX-716A, but the converse is also true.

I do not know the details of this DAE test that Triza mentioned and until I do, I am a somewhat skeptical of the results. Did the test include the use of PlexTools with the Plextor drives? The characterization of a drive's DAE performance should not be limited by what software is used. I have found that my PX-716A does a better job with PlexTools than with EAC (or any other piece of software that I've tried).

How do Plextor drives favor against the Lite-On SOHR-5239V in spoon's database?

The DAE Quality test involves ripping a reference WAV image back from an intentionally damaged CD-R while using a non secure reading mode like EAC's burst mode. Then a special program is used to compare the reference WAV image to the ripped back WAV image and then a report is made about the drives error correction and concealement capabilities etc.

The whole project is fully described here :

http://www.exactaudiocopy.de/eac13.html

i had te same issue wit a liteon 48x burner

Burning at 32x gave way more c1 errors than when I burnede on 40x

40x was te write speed with the least amount of c1 errors on my verbatime disk.

well I tried it on the HL-DT-ST GMA-4082N in my Thinkpad and while the firmware doesn't slow it down by itself when it runs into errors, it does exhibit the same behaviour. More errors at slower speeds.

is this more common than it`s actually thought to be ? or am I among the unlucky few ?

Anyone with "better" or "popular" drives care to do such a test ? I use a lightly scratched CD and run the Disc Quality or ScanDisc test and see how many C2 errors (max/total) I get at different speeds.

I did the DAE tests that is featured on the Exact Audio Website. I had a test disc I used before with a number of drives, but PX-716A simply refused ripping when it reached the tough part. Then I built at least 5 test disc until I managed to tame them enough so PX-716A could rip it. Both PX-716A and Premium was rereading up to 20 times. It took ages. There were lots of errors. PX-716A has no proper interpolation. It had spikes around -12 dB. Premium was better but only if I had a lot of retries. This particular Liteon did not need any reread and ripped the 70 min test disc in 3 minutes and 7 out of 10 times without errors. I sold my expensive Plextor Premium as a result. The Plextor tests were done using Plextools. Once I tried just a single run burst mode with EAC, but the results were truly horrible. Premium too. Most of the magic must be in Plextools. This is not the end. When I upgraded from 2.28 to 2.32 I got worse DAE results. I downgraded back and I got better results. They behaved noticably different. This was the last straw. Plextools is so buggy anyway. I gave up on Plextor.

Triza