Cd player - output capacitors - electro to film ?

[MaccAu]

Hi All,

I am wondering what is the favourite replacement (upgrade) film caps for CD players output

non polar 47uf 50v

I was thinking 3,3uf and maybe that is too low, or 4.7uf? what are the favourite capacitance and films to use.

I was considering, and have used in the past Jantzen superior Z, but is costly and I had help with that player from the seller 🙂

Audyn Cap MKP Plus (relatively small size)
Ampohm ( a bit larger but doable )
Mundorf Evo Oil ( compact than the above) ?
cheaper Jantzen crosscap or Mcap?

 

[analog_sa]

Are caps really essential? Assuming it's an opamp output have you measured the offset?

 

[Rundmaus]

Choosing capacitors is not like choosing your favourite flavour of coffee. It doesn't depend on what you like best, but what is required for the circuit to work.

If there's a 47µF cap in the output, it has been chosen to set a certain time constant or cutoff frequency. Replacing it with stylish 'superior copper gold extra audiophile' stuff with 1/10 the original capacitance will likely throw the frequency response off. Which in turn will be praised by certain 'audiophiles' for its richness and clarity.

If the original output cap is 47µF, replace it by whatever audiophile snake oil you like, but make sure to use snake oil with 47µF capacitance and at least 50V voltage capability.

Regards,
Rundmaus

 

[Rundmaus]

Are caps really essential? Assuming it's an opamp output have you measured the offset?

Assumed it is a commercially produced CD player, I am almost sure the manufacturer would have left out the cap if it is not needed, to save a few cents.

Regards,
Rundmaus

 

[analog_sa]

Not necessarily. The question is how much dc can be tolerated. I have no issues with 5mV which in may cases can be achieved by choosing a suitable opamp. Opamp rolling is not only cheaper than cap rolling but may entirely eliminate the cap...a big plus in my book.

Of course not all designs are suitable for a dc connection to pre/power amp. Especially if no power on mute.

 

[Rundmaus]

OK. In certain cases it might be possible to leave out the cap, if you analyzed the circuit, know what you are doing and the rest of the setup tolerates this change.

But it requires a basic understanding of the circuits involved and the role of the output cap in question to consider the consequences of leaving it out.

To be honest, the fact that the thread opener asks for 'favourite capacitances' makes me doubt he's bringing along a sufficient understanding of electronics to decide if it's possible to leave out that cap.

Regards,
Rundmaus

 

[MaccAu]

Hello Analog, not sure if i can leave it out. Thanks for the reply and help

Hello Rundmaus, thanks for the reply and help. I am best to stick with 47uf, that is fine I can use silmicII, which is very good, and has been great in my other cd players, no need to worry then about trying to fit them in.

Though they would be nice caps for speaker crossovers, used Jantzen Superior Z in my speaker crossovers, but I like the mundorf range, but never tired them apart from the resistors.

 

[TonyTecson]

if the next stage input impedance is high, then 2.2 or even 1 ufd will do....

 

[Rundmaus]

if the next stage input impedance is high, then 2.2 or even 1 ufd will do....

Maybe. But I would not consider it to be a wise step to modify a signal source in a way that makes its correct function depending on what I put there as the next stage. Do you really want to modify your player again when you switch to a different preamp later?

Regards,
Rundmaus

 

[TonyTecson]

Do you really want to modify your player again when you switch to a different preamp later?

not necessarily so.....

when i was younger, i used to think that the bigger the cap, the better.....
but from my own experience i found this to be not necessarily true....
in my college days, i read a book about noise and there it was mentioned
that using a bigger coupling cap is good for the noise...
so now my own rule of thumb is to use the smallest value coupling cap to taste....
your milage may vary of course...

 

[MaccAu]

Thanks AJT, for the help. I have no idea what the input impedance is though i tired a 6,8uf in place of the 22uf bps in my Technics cd player and it works and sounds great

An externally hosted image should be here but it was not working when we last tested it.

Hi Rundamaus, so i can get a film 45uf that is small enough, would it be better than the silmicII? like a Jantzen crosscap or a small mundorf

 

[TonyTecson]

non polar 47uf 50v

are you sure that is not a .47ufd/50v cap?
non polar 47uf 50v caps are quite big physically...
can you post pictures of the original cap please....?

 

[Rundmaus]

It's neither 'the bigger the better' nor 'the smaller the better', I think. Best output cap is the one that gives the time constant required by the circuit and intended by the (hopefully competent) circuit designer.

Regards,
Rundmaus

 

[Rundmaus]

Oh my.

Sorry to disappoint you, but the modification shown in the picture is an almost certain recipe to reduce sound quality, whatever exotic cap is used.

The replacement caps are physically too large and are connected to the board by single wires forming large current loops. This invites all interference present in your environment to couple into the signal path.

There's also no use in decoupling an already small film cap by another even smaller cap. This is useful to reduce impedance on power supply reservoir caps, but makes no sense for a coupling cap. Again, with the long leads it only adds loop area and makes the circuit more sensitive to RF or other electromagnetic interference.

If you hear any improvement with this configuration, it seems you like interference. 😉

Regards,
Rundmaus

 

[TonyTecson]

It's neither 'the bigger the better' nor 'the smaller the better', I think. Best output cap is the one that gives the time constant required by the circuit and intended by the (hopefully competent) circuit designer.

Regards,
Rundmaus

assuming the output impedance of the cd player was 1k ohms, then if the
the input impedance of the preamp was 100k......

then a 47ufd will give a corner frequency of 0.47hz.....
now assuming that that cap was terminated with a 100k resistor,
so now the corner frequency becomes 0.7 hz....

so now what if the cap was 0.47ufd?
corner frequency becomes 6.77 hz, still very low enough to cause
phase shifts at the audible range....

this is the online calculator that i used......RC pad corner frequency upper and lower cutoff frequency calculation filter calculate time constant tau RC voltage power calculator capacitance resistance - sengpielaudio Sengpiel Berlin

 

[MaccAu]

are you sure that is not a .47ufd/50v cap?
non polar 47uf 50v caps are quite big physically...
can you post pictures of the original cap please....?

Hi Sorry the player in the photo original caps are below picture was 22uf 16v B.P. The other player they 47uf 50v caps i dont have anymore but they are about the size of a replacement silmicII in the same value

An externally hosted image should be here but it was not working when we last tested it.

 

[TonyTecson]

i may be able to tell folks about the technical aspects of their choices.....
but i can never tell them how to enjoy their music....

 

[MaccAu]

Oh my.

Sorry to disappoint you, but the modification shown in the picture is an almost certain recipe to reduce sound quality, whatever exotic cap is used.

The replacement caps are physically too large and are connected to the board by single wires forming large current loops. This invites all interference present in your environment to couple into the signal path.

There's also no use in decoupling an already small film cap by another even smaller cap. This is useful to reduce impedance on power supply reservoir caps, but makes no sense for a coupling cap. Again, with the long leads it only adds loop area and makes the circuit more sensitive to RF or other electromagnetic interference.

If you hear any improvement with this configuration, it seems you like interference. 😉

Regards,
Rundmaus

Hi Rundmaus,
Maybe the improvement was the opamp - LME49860 🙂, though the similar Technics player (not modded) untouched but with OPA1642 opamps sounds as good 😕😛

I did use obbligato cap (large caps and Neotech upocc copper 24awg), what are the signs of interferance?

Hi AJT and Rundmaus

This is the circuit for the 45uf 50v player

An externally hosted image should be here but it was not working when we last tested it.

Circuit for the 22uf bp player

An externally hosted image should be here but it was not working when we last tested it.

 

[TonyTecson]

fixed load of 4.7k for the output stage op amps, 47k terminating resistors after the cap...
rails of only +-7.5 volts, not sure what the designer considerations were, but
i suspect that noise was top of the list....i could be wrong...

if i were to mod that, i will try to raise the rails some what +-12 volts....

 

[MaccAu]

fixed load of 4.7k for the output stage op amps, 47k terminating resistors after the cap...
rails of only +-7.5 volts, not sure what the designer considerations were, but
i suspect that noise was top of the list....i could be wrong...

if i were to mod that, i will try to raise the rails some what +-12 volts....

Thanks AJT, so to get the extra volts, you would increase capacitance or add a seperate power supply to the opamp?

A friend who i made when i bought a Philip CD753, gave the opamp its own power supply.