TDA1540 decoupling caps

[wutzke]

Hi All,

I am about to replace the TDA1540 decoupling caps (Pin 12-14, 18-25) on my CD304. But I am not sure about the vaues.
Some say 2.2uF for the MSB, 470nF for the next then 220nF ...
Some say 1uF, 680nF, 470nF, 220nF...

I have some wimas, should I take MKP, MKT or MKS?

Also, what do you think about replaycing the oscillator cap?

Regards

 

[erin]

TDA 1540 or 1541?

the values required for the TDA1540 are on the TDA1540 datasheet.
Likewise for the TDA1541.
Use MKP.
use a silver mica 470pf for the oscillator cap.
🙂

 

[wutzke]

Thanks for your reply Erin.

It's a TDA 1540.

The values on the datasheet are:
470nF, 220nF, 100nF, 47nF, 22nF, 10nF...
The Philips CD304 has the following values:
470nF, 470nF, 100nF, 100nF, 100nF, 22nF...

I am wondering if increasing the values would be an improvement?

 

[erin]

The standard datasheet values will be the most appropriate, as the cap values are chosen ( i think) according to the current the bit switch uses, and generates, and the frequency the bit switch is activated. ( sorry my understanding is a little limited here, hence the vague explaination) But If Philips used those values on your CD player, then perhaps you should go with that?

You could change the values slightly and I have no doubt that you will get a different sound. But whether it is better, you can only decide for yourself.

AS for the oscillator cap. use silver mica, but not sure of the TDA1540 value.
the value I gave before is for the TDA1541.

 

[wutzke]

Thanks,
I don't think slightly increased capacitor values will hurt.
I will try, and share my experience with you.

 

[erin]

Please do let us know your findings.
There are too many threads without an ending.
Its good to have closure.
good luck!