Separate regs for ICs on Marantz CD63

[britain4]

Here’s one for the DIYers - I’m currently modding my Marantz CD63 and wish to clean up the voltage supplies to the various ICs on the board.

Firstly - a lot of people advocate a separate regulated supply for each voltage feed on each of the ICs, Thorsten Loesch on TNT Audio describes excellent results just from fitting chokes and ferrites to the voltage feeds to clean up the noise without going to the lengths of a separate clean supply. Anyone know whether the regs are worth the extra effort/wires in practice?

Secondly I’m wondering the best way exactly to fit the regs, I was thinking a piece of stripboard with a row of LM340T5s on it all supplied from the 10v rail after the transformer and all connected to ground via a 500 ohm resistor as they are very small currents for the regs to be supplying - then wires from each reg to each voltage feed on the board. Any issues with this in practice with noise induced over the length of the wire for instance, or noise generated between the regs?

The other way would be to fit the reg output physically at the voltage supply on the board and have a separate 10v feed to each one - this would be a bit messier and more difficult especially concerning the resistor between the reg and ground, but doable, easier if you build your own regs but I wasn’t wanting to go to those lengths.

 

[insider9]

My DIY skills are not on as advanced level yet. I don't know how many on here will be able to help. I'd suggest posting on diyaudio.com

 

[britain4]

Nor are mine, pretty new to all this! I understand how to do the digital and analogue feeds of the DAC but I’m starting to feel the rest is beyond my skill level and I should just stick to filtering with inductors/ferrites.

I have done that as well, more familiar with here though so wondered if anyone else had been down the path.

 

[andyjm]

Nor are mine, pretty new to all this! I understand how to do the digital and analogue feeds of the DAC but I’m starting to feel the rest is beyond my skill level and I should just stick to filtering with inductors/ferrites.

I have done that as well, more familiar with here though so wondered if anyone else had been down the path.

A clean supply to the analogue stages in a CD player is never a bad idea. There are many designs for low noise, highly stable low current suppplies. One that seems to have quite a following is the 'Jung super regulator' which as far as I can see is a regulator followed by a regulator. I am sceptical whether this would be better than a few well placed Ls and Cs, but there are some who swear by it. Apart from decoupling caps, there is no point trying to clean up the supplies to the digital ICs in the player.

 

[britain4]

Nor are mine, pretty new to all this! I understand how to do the digital and analogue feeds of the DAC but I’m starting to feel the rest is beyond my skill level and I should just stick to filtering with inductors/ferrites.

I have done that as well, more familiar with here though so wondered if anyone else had been down the path.

A clean supply to the analogue stages in a CD player is never a bad idea. There are many designs for low noise, highly stable low current suppplies. One that seems to have quite a following is the 'Jung super regulator' which as far as I can see is a regulator followed by a regulator. I am sceptical whether this would be better than a few well placed Ls and Cs, but there are some who swear by it. Apart from decoupling caps, there is no point trying to clean up the supplies to the digital ICs in the player.

Yeah I’ve heard it makes big improvements on the CD63 in particular so wanted to give it a try for myself. I’ve seen ones modded with about 25 new regulators in there but that seems a bit overkill...

The reading I have done includes cleaning up the digital supplies as well as the analogue ones - something do do with the fact that the clock’s built in to the DAC chip - guess the jury’s out on that one...