Basic CD player Mods - where to start

[Mooly]

Originally Posted by Tosh

And my older DVD player in which I had previously beefed up the caps and put in nicer diodes (1N4947) has an SMD (NJM4558?) opamp to practice on, so I'm going to psych myself up for that...

Easy

Working with SMD. How to do it without specialised tools.

[Andersonix]

Thanks Mooly, I actually read that thread when it was new. In my case it will be even easier once I snip the legs off the old op amp. I'm mostly worried about lifting pads on these cheap pcbs.

When doing little mods, it would be nice to do one change at a time to be able to hear the effects of say, the diodes, then the caps, but then once you have it all apart and the pcb out you just want to get it all done and never go back inside.

For sure, that OP249 was garbage, yet B&K had specially selected it for the AVP1000 preamp.

[SoNic_real_one]

I am using the Chip Quick solder to remove the cips. It is working...

[a.wayne]

Originally Posted by Tosh

Indeed by far the single biggest improvement in my system came from swapping OP249 in my preamp for LM4562. I cannot gush enough about this op amp! No amount of fooling with the PS could approach the difference the LM4562 made!

And my older DVD player in which I had previously beefed up the caps and put in nicer diodes (1N4947) has an SMD (NJM4558?) opamp to practice on, so I'm going to psych myself up for that...

Great ...... not sure i want to tackle the op-amp deal just yet !

Originally Posted by abraxalito

Turns out that this one was listed at USD1895 (in 2002). Can't find a consistent story about what DACs it uses - one site says it thinks BB and another, Wolfson. What's obviousy a marketing smokescreen is Rega's claim (on their website) that the DACs are 'custom built IC40 DAC chips' and 'Rega 24 Bit Sigma Delta IC40 DAC'. Rega does not generate the sales volumes to build its own DAC chips.

Yes that price new is correct . The isolation is horrible IMO and i have been working on this with some improvement , mostly no skipping on crescendos and added mass to the top case ....

Regading the dac chip, what would one change this 2 , what is a good ,better , best , DAC chip ?

Originally Posted by SimontY

2604 sound awful to me. LM4562 are very smooth and clean (can seem clinical in some players). 5532/5534/JRC2114 are musical but grainy. I heard 249 once and they were rubbish.

If the Jupiter comes with op-amps these can be changed. A clock upgrade is also very easy usually.

Power supply mods are the most important thing for any cd player! The op-amps can change the character and grain but not the real quality.

Simon

My first goal is to tackle the PSU , a Better power cord did make a difference , next will be diodes , caps and what is your thoughts on separate supplies with bigger tranny ?


Still looking for a service manual ..................... !
,

[abraxalito]

Originally Posted by a.wayne

Regading the dac chip, what would one change this 2 , what is a good ,better , best , DAC chip ?

On the basis that its probably a Wolfson WM8740 I'd be inclined to leave it alone for the time being until you've improved the grounding, the supplies and the clock. Then after those are sorted you could try BB or ADI (PCM1792/4 or AD1853/1955). No point in upgrading the DAC when the rest of the infrastructure sucks Do those things really suck in a $2000 player though?

[SimontY]

Originally Posted by a.wayne

what is your thoughts on separate supplies with bigger tranny ?

Go for it! Many separate supplies is something no player comes with as standard. Even the huge Naim ones with an external supply usually just tap off one tx winding and supply.

When you pay more you usually get better separation between power rails but it's typically just done using regulators, which is a great start (but can be improved upon significantly). This is the case up to at least £2000+ players. I've not seen inside many beyond that price point so I'm not sure if they go further with psu separation or not.

Simon

[a.wayne]

Originally Posted by abraxalito

On the basis that its probably a Wolfson WM8740 I'd be inclined to leave it alone for the time being until you've improved the grounding, the supplies and the clock. Then after those are sorted you could try BB or ADI (PCM1792/4 or AD1853/1955). No point in upgrading the DAC when the rest of the infrastructure sucks Do those things really suck in a $2000 player though?

Originally Posted by SimontY

Go for it! Many separate supplies is something no player comes with as standard. Even the huge Naim ones with an external supply usually just tap off one tx winding and supply.

When you pay more you usually get better separation between power rails but it's typically just done using regulators, which is a great start (but can be improved upon significantly). This is the case up to at least £2000+ players. I've not seen inside many beyond that price point so I'm not sure if they go further with psu separation or not.

Simon

Well guys this is what i have found out so far .... Supposedly it does have separate supplies and a Wolfson DAC chip :


Power supplies, the importance of which is highlighted in the Jupiter. It has seven! Rega uses a high performance Sony CD mechanism, and to minimize the effect of footfalls, a case isolation system (they call it the Viscous Coupled Foot System, better known to us Regaphiles as 'squishy feet'). Along with the better power supply(s), the primary improvement is in the DACs. The dual differential 24 bit IC40 DAC chips are sourced from Edinburgh's Wolfson Microelectronics. Additionally, Rega has taken the greatest care with both data regeneration and clocking stages.