Servo noise from heavily (!!) tweaked 16 bit CD player

[A 8]

I agree with both Erics. I had the same issue when I started modding cdp's a long time ago and it always disapeared when turning my attention to grounding.

 

[Dr.H]

Hi Fin,

Never got to the bottom of it, but it was through lack of time. Anyway, the noise was really low level.

The machine was a Rotel 855/955 and the additional transformers were mounted on the rear panel outside the box.

I have since used a Proceed PDT3 in combo with a Theta DS Pro Prime, which gives a cleaner, more detailed presentatin.

 

[DIAR]

This hasn't got anything to do with this particular problem but I have noticed with my Sony DVP NS900 player that the small clamp on top of the disk can easily be misplaced for example when moving the player. When the clamp changes position it will not be placed exactly to center when a disc is inserted. If the clamp is misplaced, the transport can cause noise. The clamp is easy to move to center by pressing a nail (or what ever) against its edge and gently push it to center. The disk must spin while doing this.

In this picture, the clamp is seriously misplaced.

 

[Fin]

Hi Ryan

The machine was a Rotel 855/955 and the additional transformers were mounted on the rear panel outside the box.

Good Idea!

I've been trying to think of ways to add more transformers to an Arcam 70.2 - which is quite full already.

Did you attach a metal case to the rear panel to enclose the transformers?

 

[Dr.H]

Hi Fin,

No, no box to enclose, but I am sure quite easily arranged. I must say that I found in general that the 16 bit TDA1541 was quite immune to major power supply mods, unlike its 1 bit cousin the SAA7350. With the latter, I found significant sound improvements with seperate power supplies etc, while the TDA1541 showed marginal improvements.
In fact if I recall correctly, the 1541 showed most benefit from:
1. The DEM circuit described here
2. Increasing the size of the 14 decoupling caps and using oscons on the MSB pins
3. There are some other mods described here and on audioasylum that work.

Regards
Ryan

 

[Fin]

I must say that I found in general that the 16 bit TDA1541 was quite immune to major power supply mods, unlike its 1 bit cousin the SAA7350. With the latter, I found significant sound improvements with seperate power supplies etc, while the TDA1541 showed marginal improvements.

This is good to know in advance! The Arcam already has a separate transformer for the audioboard - so maybe that's enough.

From what you say - it could be better to put my two extra transformers into my CD624 (SAA7321 - 1Bit).