Error correction of PWT


#1

I have the venerable PS Audio Lambda transport. It plays through all the drop-outs on the Pierre Verany Digital Test CD. There are 24 tracks in three groups with tracks of increasing difficulty within each group. The first group is individual drop outs and the other two contain drop outs close together. The Lambda passed them all, even the last track in each group which is the most challenging. The largest drop out is 4.00mm visible to the naked eye. My OPPO 205 player is almost as good but stumbles on very largest drop out.

I have a disk with some drop outs one track. Both the Lambda and the OPPO play them perfectly. However, my PWT coughs and chokes and ultimately can play the selection.

What could be wrong?


#2

If I remember right the PWT does not use conventional error correction. Instead it keeps rereading the data until it can get it right. I am sure someone from PS Audio could better explain this.


#3

This is correct. The PWT uses a form of EAC (Exact Audio Copy) that reads until the data is right, then stores it in a RAM buffer.


#4

I never felt that my PWT had any issues playing compromised disks. I remember finding a Boys to Men CD laying on a Blacktop side walk label side up scratched to hell. I took it home cleaned it and played it. It did not mistrack or give me any indication that it was anything other than a normal CD. It shocked me that it would even play.


#5

Does that mean for that this particular error, even multiple reads can’t correct it?


#6

That would be my best guess.


#7

I agree with Paul but that should bot be a concern as the test disk is a worse case scenario. If you could see what that Boys II Men CD looked like you would realize that the PWT can really plow through quite a mess and still make music.