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cdp distorts with cd-r, transport perfect

Hi all, I have an Onkyo dx-6750 integra cd player, which I purcased as defective. I cleaned it and set it up with an oscilloscope, the transport is perfect now. Nice eye pattern, nice TE and FE signals, seeks fast, no skipping, no problems at all, nice sound - but with original cds only. When I try to play a cd-r disc, the transport still reads perfectly but the sound is distorted. If I take a look at the audio signal with the scope I see a somewhat "stepped" signal. Now, I just can't see if it's the transport or the digital circuits causing the problem. It's unlikely the transport because there are no signs of any difficulties with reading the data. And it's unlikely the digital circuits because once the data is read off of the disc I can't see how the rest of the circuits can make difference between different discs. Any ideas? m127

Reply to
mszaloczy
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Sometimes it makes a difference what speed the CD-R was recorded at. (12X,

24X, etc) You could try CD-R's which were recorded at a lower speed and see if that makes a difference.

I have found this to be especially true of players which are Philips based. Since your model is not listed in my American Onkyo servicers' website, I am unable to examine the technical data.

Mark Z.

Reply to
Mark D. Zacharias

P.S.

There are some "silver" CD-R's you could try.

There may not be anything you can do to get it to play your existing CD-R's.

Mark Z.

Reply to
Mark D. Zacharias

Oh I see! I just thought that if it had a serious problem with those discs it would not play them at all but mute or stop. The unbelieveable thing was that it played, but distorted. Anyway, I have a nice little bunch of cd-players, some good ones also, like a Teac VRDS-10SE, a Teac CD-5, a better Onkyo (DX-6870), two Denons (dcd-755 and 1450), a B&O Beogram etc, so this Onkyo DX-6750 is to be for sale soon anyway. I just wondered if I could do anything to make it better and to sell it better. :)

Another good idea is to keep it as a parts backup for my DX-6870 since the mechanical parts are the same. The interesting thin is that the 6870 doesn't have the problem the

6750 has. They have the same transport. I still find it a very interesting question if the transport or other parts are the origin of the cd-r distortion problem.
Reply to
m127

try recording a cdr with another computer

could be the sampling freq on the sound card in your pc or the servo speed on your cd burner is just a little out of range for the player

did you try tweaking the FE and TE loops when the CD-R is playing?

Mark

Reply to
Mark

Hi Mark,

Yes, I tried playing with Focus and Tracking, using a scope and listening to the sound. I didn't manage to take out the distortion, and now the servos are set at the best possible. I think my writer is OK, it's a very good plextor, writes crazy good discs that can be played on anything all over the world. I also played some discs written by others, and the distortion is still there. Anyway, I want to sell this player sooner or later, so it's not my discs that are the problem, I just wanted the player to be able to play more discs than it plays now. Someone somewhere told me that the origin of the problem can be the error correction, he said the player may have c2 errors with cd-r and leaves out some samples while playing back. Well, I don't know. I'm not that good in error correction and cannot monitor how many errors the player has got (and if it differs with different discs).

Reply to
m127

try asking on rec.audio.pro Mark

Reply to
Mark

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