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CDX Mods?

MartinC

pfm Member
Now that my CDX is a few years old, perhaps it's time to consider tweaks. A couple of possibilities seem to surface, namely:

i) Upgrade the clock

ii) Add some 'Weeks Tweaks' in the form of Superregulators to the analogue sections. (Perhaps the easiest route is to add these to the XPS?)

Anyone elso on the Forum tried any CDX mods? I suspect that with both of these mods done performance approaching that of a CD2 should be attainable.

I would also be interested if anyone wants to collaborate on modifications, sharing in the trials and tribulations!

Thanks

Martin
 
Having done a clock mod on a low end player, I can confirm that is is a simply staggering upgrade, however, look carefully at the way the clock is designed in the CDX, it would surprise me if it was just a simple oscillator and you may do more harm than good.

Regarding the regulation, it may be best to replace the local regulation with super regs for critical components. Try them in different places and see what produces the best result. I imagine (although I am happy to stand corrected) that isolating superregs on the other side of a Burndy and a local three legged regulator on board the player may cramp its style somewhat.

Cheers,

Ed
 
Les at Avondale did a few mods to my CDX one of which was replacing the digital filter with the one used in the Linn cd12.I do not know what else was done but the cost was £285.Les does not think much of the CDX and did not consider it worth spending more.Better mod a cd3 or an Arcam Alpha

Gordon
 
Martin,
I'll nervously join you in trying out a few modifications, although you are already one (rather large) step ahead of me in that you are using an XPS. I don't intend to buy an XPS but build something along the same lines.
I would agree with the area's you propose to modify with the addition of perhaps changing the analogue section op-amps, although I don't know what is in there at the moment.
Where would you like to start? Trace out the clock circuit?
Ashley
 
One thing to investigate is what DAC is used.

If it's a voltage out device, then fine, but if it's current output, the chances are an op-amp will have been used as an I-V converter - these are a simple, but non-optimal solution.

A discrete circuit could offer much better linearity (or possibly a CFB amp).

I suspect the clock will be 74HCU04 based - this is not necessarily a bad thing and is likely to respond to simpler ways to reduce phase noise initially (like PSU improvements).

Andy.
 
Ashley, Andy et Al,

Figuring out the internals of the CDX is my first step. May be a few weeks though as we are moving house (listening room moves from a nasty 11'x11'x8' to a better 15'x12'x3').

I think that the CDX uses a simple oscillator for the clock but it is a good time since I looked inside. Will keep y'all posted!!

Cheers

Martin
 
Martin,
Are the above new room dimensions correct?

I'm picturing dwarfs dancing around a miniature Stonehenge.

Ron The Mon
 
Hi, anguila (& Les?)
You say Les doesn't think much of the CDX.
Hmmm, the general consensus here seems to be it's quite a good CD player.
I wonder if it was more that it doesn't lend itself to upgrades (ie. what Les does), rather than it's not a damn good machine already?
 
I personally think the cdx is a competitive player.I think Les has posted before that he is not impressed.After I had my cdx breathed on I asked Les to build me an XPS type power supply but he said it was not worth it.At that time he said he had a DAC coming out and I would be better waiting for that.I have not heard anything more about that.If you want the full lowdown on what he thinks of the CDX it would be best to talk to him

Regards Gordon
 


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