cause for digital glare?

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Hi all



A buddy has asked me to take a look at his cd player. It's a lector cdp7 and normally is very smooth sounding,very good cdp indeed. However since Christmas there has been a harshness in it, a kind of glassiness or glare that previously was not there.

It uses a cdm12 mech, custom controller into a Pcm 1704 dac and a tube output stage using 12at7 valves - its a cathode follower I think. Under the cover everything "looks" ok with nothing scorched or anything:

Does anyone have any ideas where to start looking at this? I've emailed the manufacturer and have gotten some info but I need more (and to educate myself too).


Thanks in advance....


Fran
 
In your opinion, do you think there is a problem with it ? or could it be that you have (your friend) just suddenly become dissatisfied with it somehow.

It's all a matter of degree... is it distorted ? both channels ?
or do you think it's like going from say £2000 player to an £600 one (for example) where you are not so sure, or it becomes hard to describe differences.

The 12AT7... I'm assuming it uses just one as it's a double triode... is the obvious thing to change... as valves do deteriorate and lose emmision.
 
Yes, there is definitely a harshness in it that wasn't there before. We've eliminated all the other things in his set up, and also brought it to other peoples places and the same result.

We also have tried 3 other sets of valves (2x 12AT7), including a NOS set of mullards from Jim McShane (whom I would trust).

It is hard to describe, but you know that kind of hard edge you get from lesser players sometimes, hard edged vocals, massed violins taking your ears off etc....


Fran
 
Does anyone have any ideas where to start looking at this?

Maybe the capacitors finally broke in and are now letting the full glory of the cd sound come through 🙂

You mention very little background. How long has the owner had the cdp? Do you trust he hasn't done anything else to the system - like changed power points/plugs/cords/mechanical support or anything else? Are other digital sources unaffected? Maybe one of the neighbours has a really noisy new gadget polluting the power line.

Too many possibilities. The least likely place to look for an answer seems the cdp.
 
Yes we have tried other digital sources (and analog🙂) and we switch back to the lector and can hear the glare. We did try other cables etc but same difference - and of course back to original as well.


There are a pair of trimpots on the dac board (pcm1704) - in an earlier Pcm63 version I think these were used to adjust output level or bias. You adjusted them with a 1khz signal playing. what do they do on a 1704?


Fran
 
Hi Fran, would it be possible (or have you already) tried another digital source through this player, using the Lector as a DAC only? (I'm not sure if this is possible with the Lector.) Only I've heard this sound before and in my case it was the laser / laser assembly. You get a very hard etched sound when they are on their way out. But testing with the above (if possible) could rule this out/in.

If it is on the way out then you are just looking for a replacement, which I hope you should be able to find fairy cheaply. Not sure how easy it will be to change though, some are easy, but some CD players are really quite tricky.

Hope this helps,
Russ
 
It should be under warranty. Take it back to have it fixed! A company like Lector will probably be good to work with. I've had to get a few high end components fixed over the years. Most of them are great to work with.

Or turn a pc into a cd player and forget the dedicated player. Does the player have a digital input or output? If so you have some other options as another rjbaldwin was suggesting. Most of these top flight players have dig ins/outs.
 
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