decoupling TDA1541A

[till]

hi,
2 questions

Is WIMA MKS-2 100nF ok for the 14 decoupling caps of 1541,

and why is on some schematics pin 13 and 18 decoupled with larger caps (some uF) ?

 

[jean-paul]

Those are the MSB pins. Arcam used tantalum caps for that but I sure would not recommend those unreliable caps.

Wima MKS is OK ( no more than that ) but 220 nF instead of 100 nF is slightly better. Avoid long wires to the caps ( bigger is not better here ). Peter Daniel tried BG NX Hi Q there with good results IIRC. I never tried them on that spot.

Discussions about the value can last long, some will propose 1 uF. Better try it and choose yourself what you like best. Datasheet says 100 nF so that should be enough. Quality of the caps has more priority than the 100 nF/220 nF/ 1 uF question IMO. Polypropylene ( Wima MKP 10, 100 nF or 220 nF ) caps are a wise choice considering cost/quality.

 

[Bricolo]

But the size is also a concern, since you have to place 7 caps per side.

I wanted polypropylene too, but the 1uF ones were way too big.
I'm on the way to buy some wima MKS-2 too

PS: jean-paul, are you sure about the location of the MBS pins? Elso and Thorsten don't agree about that

 

[siu sin man tho]

I test many decoupling caps in the 1541a. I feel tin foil is quite good.

this is my opinion.

thanks

thomas

 

[jean-paul]

Just checked for you and in various schematics of brands that bought their stuff and technology from Philips pins 13 and 18 have the label MSB. For instance Arcam used 0.47 uF on that pins. I used the same value on all pins like the datasheet says.

Of course size is a concern as I tried to make clear. 220 nF MKP will fit, I never thought of using 1 uF.

 

[mdlover]

Hi all,

I have tried Philips MKP (130nF) and Siemens stacked film (470nF) for those decoupling caps. Both sound smooth and natural. Personally prefer Siemens stacked film more (may be the value?)
😉

Will try BlackGate N, Nx soon.

Below pics showing the board using Philips MKP. 🙂

pics for Siemens stacked film will follow.

 

[jean-paul]

Nice board ! Wish I got the design around the TDA right.

 

[Bricolo]

The wimas MKP-2 0.1uF are the same size as the MKS-2 1uF

So, I will be able to try, when I'll be rich 😀

 

[Bricolo]

Just checked for you and in various schematics of brands that bought their stuff and technology from Philips pins 13 and 18 have the label MSB. For instance Arcam used 0.47 uF on that pins. I used the same value on all pins like the datasheet says.

Of course size is a concern as I tried to make clear. 220 nF MKP will fit, I never thought of using 1 uF.

so Thorsten was wrong
http://www.fortunecity.com/rivendell/xentar/1179/projects/adagio/Adagio.html

 

[jean-paul]

I think that's an error in the drawing. It seems to me that the creator of the chip knows what pin is MSB. When the same value for all pins is used we won't need to discuss about that 😉

BTW I have an amount of MKP10 100 nF and they were very cheap. No need to be rich for buying MKP10. They're small too. They may not be the best but their price/quality ratio is hard to beat.

Who said Mundorf ?

 

[weissi]

Why not use NPO ceramics???? these are high frequency decoupling points, so ceramic won´t hurt. Not those 4cm MKP´s...
I wasn´t able to hear a difference when I changed the ceramic C´s in my CD50 to SMD polypropylensulfids......
OK, NPO 220nF cost much, but IMHO they should be way better than some of that monster caps....


I used these cap´s:

http://www.panasonic.com/industrial/components/pdf/ABD0000CE13.pdf

 

[till]

Reichelt

100nF
FKP1 0,82€
MKP10 0,61€
MKS4 0,12€
MKS2 0,07€
ceram. 0,06€

as i need ca. 50 of them for this http://www.diyaudio.com/forums/showthread.php?postid=346671#post346671
with TDA1541A instead of TDA1543N i´ll go with MKS2 if there´s nothing really against.

 

[zygibajt]

>Bricolo

Don't use Wima,they are not that good.
The best cheap caps i found for that purpose (much better than Wima) were small orange Philips polypropylene 1uF/63.They are really small ,about the size of op-amp and they sound good.
my friend prefers small 470n Rifa over Philips ,says they are better,but I haven't tried this yet.Bipolar Black Gate might be better still,and they are not that expensive either.

Bartek

 

[mdlover]

here is the board using Siemens decoupling caps.

now i'm thinking of using BG-N 0.1u or BG-NX 0.47u and wonder how they sound. 🙂

cheers

 

[Bernhard]

I think that's an error in the drawing. It seems to me that the creator of the chip knows what pin is MSB. When the same value for all pins is used we won't need to discuss about that 😉

How wise...

I'm wise too.

Because it seems to me that the creator of a pair of chips knows which one is the economy - low performance and which one the high performance.

But lots of DIYers question that.

as i need ca. 50 of them for this

4 x 1541 ?

I have tin foil 0,15µ, but they are 15mm diameter 🙁

 

[Bricolo]

Would BC caps (philips) BC371 be better than WIMAs MKS?
Both are polyester

 

[Bernhard]

IMHO it is very important that the rolled film caps have contact material all over the flat end faces and the wires bonded to them.

So rolled MKP caps will be low inductive like the stacked Siemens MKTs.
But better because they are MKP.

If the wires are just sticked into like old or cheap styroflex, they will be inductive and also the electrical contact will be not so good.

15mm tin foil caps:

 

[Bernhard]

Or like this:

 

[Bricolo]

Isn't it better to place the caps this way, rather than to align them?
The path seems shorter with this configuration

 

[Bernhard]

Isn't it better to place the caps this way, rather than to align them?
The path seems shorter with this configuration

No.

Foil caps are mostly long.
And this way the path is prolonged by the lenght of the cap.
Only useful if you want to use very fat 1µ Siemens MKT stacked foil caps.
They are short.