Philips CD104 tweaks

[IAN01]

My Grundig CD7550 has developed a mechanical problem with the cd drawer so I'll be pulling it apart this weekend.

I promised a while back I'd take some pics the next time I pulled it apart and post them. If anyone wants me to look at anything in particular then shout and I'll try and provide some feedback.

[simonov]

I'd like to join IAN01. I can provide you guys with detailed pictures of my CD7550.
I already made some improvements to it. Put some high quality opamps like: LM4562 and removed the old electrolytics. Opamp's output goes trough 1uF propylene WIMA cap in parallel with 100uF Nichicon Muse. 100k load resistor at the end. No other unwanted parts. Removing the 100uF cap leads to higher rollback at low frequencies. From what I hear I could say this opamp sounds lovely and far more detailed than 5532. This feature combined with the warm and smooth sound of 1540 gives stunning results.

[petronius]

Is someone have experience to decoupling caps to tda1540 is this right values or have better?

[phimor]

Yes Ian,

I would like to see pictures

Thanks

Philippe

[jives11]

me too please. especially this earthing arrangements. From the vague descriptions in this thread I think this may be implemented where the RCA sockets connect to the chasis

[IAN01]

ok guys, I'll see what I can do

[simonov]

I threw away the output RCA PCB. As far as I can remember it was something like this. The ground wire coming from the decoder board connects to the output sockets and trough a low value resistor to the chassis of the player. The resistor is mounted on the RCA pcb.

[jives11]

I think that RCA PCB might be where the earthing changes occur as the only pictures I've seen show standard Philips boards for servo and decoders.

Is it possible that those resistors are actually something else - I have seen small pink axial resistors which were in fact capacitors, and small inductors can look like high value carbon resistors.

or maybe it's the Grundig magic smoke , which if you're not careful you will allow to escape from the unit

[IAN01]

Yep, I inhaled some last time I opened mine and now I sound better than I used too

[simonov]

Lets not forget, that this is a commercial product. So the Grundig brand needed a little advertising in order to make people buy their product. This product has been developed for the young High end market. As you know the High-end market is a bit surrounded with mystique I have both CD304 mkI and CD7550. I made comparison between these two models and they sounded pretty much the same to me. Grundig CD7550 looks way batter though Especially the silver version which sits on top of my audio rack The lack of remote control is of no concern to me