Cambridge CD3 mods - JohnW ?

[Studley]

I'm about to acquire a CD3 transport and DAC. Anybody done any worthwhile mods on these, or on the corresponding CDP?

JohnW: was this one of your designs? If so, any suggestions?

PS. Whilst we are talking, are you able to give us an update on the new DAC? (I'm sure I'm not the only one who is starting to quiver )

Thanks

Ian

[Studley]

One mod I have in mind is to clock lock the transport to the DAC's clock. However, this DAC has 2 TDA 1541s per channel (!). Will this create any difficulty in doing the clock lock?

[MJW]

I think you should do some more reading and research.
This is a very rare and classic player (please don't wreck it)

clock lock trans - dacs??? Are thinking of sync lock btwn a separate transport and dac? Ala Arcam using toslink or Guido's sync lock via coax. This dosn't apply to your single box machine. The master clock distributes a reference for the player. I can't remember now but this player may have a discrete master anyway.
but if not:

A high quality master clock with isolated power supply will give a nice up lift in performance (not one of the branded ones. They are too £££ and most of the high price is audiofool profit; I know- been there done that).
I thought the dacs were 4 parallel actually. So 4 two channel dacs whose output L/R are superimposed for greater current >out.

Have a look at lampizator (its a website) you will see a cd3 there he has modded with valves and simple passive I/V (current to voltage conversion) - 4 dacs = mucho current >>> small resistor value = low induced distortion in the dacs>>>> nice clean-ish derived voltage......

You could do something similar with a solid state output stage to replace whats there or improve whats there??

Lot's of options, modules, kits and bits are available.

I think you should spend a few months at least learning, reading buy one of those $hit box cd63's to practise on. They cost buttons, are as rare as ford escorts and know one will lament it's sad demise when you barbacue it!

[Studley]

Originally posted by MJW

clock lock trans - dacs??? Are thinking of sync lock btwn a separate transport and dac? Ala Arcam using toslink or Guido's sync lock via coax. This dosn't apply to your single box machine. The master clock distributes a reference for the player. I can't remember now but this player may have a discrete master anyway.
but if not:

A high quality master clock with isolated power supply will give a nice up lift in performance (not one of the branded ones. They are too £££ and most of the high price is audiofool profit; I know- been there done that).
I thought the dacs were 4 parallel actually. So 4 two channel dacs whose output L/R are superimposed for greater current >out.

Have a look at lampizator (its a website) you will see a cd3 there he has modded with valves and simple passive I/V (current to voltage conversion) - 4 dacs = mucho current >>> small resistor value = low induced distortion in the dacs>>>> nice clean-ish derived voltage......

You could do something similar with a solid state output stage to replace whats there or improve whats there??

MJW

Hail fellow Yorkshireman. In fact mine is not a single box machine, its an even rarer separate Trans and DAC, so yes I was thinking about a sync lock of the kind you refer to. And I definitely don't want to wreck it!

I've seen Lampizator but before following his example I'd be keen to hear from others who have tried his mod and what they think of the results.

Cheers
Ian