Hello,
I'm able to buy a large quantity of X2 type 10% (yellow) capacitors. I intend to use them in my (pre-)amplifiers for a audio mixer.
The question I have is of the soundquality will be effected negative? Does anybody have experience with these types in audio equipment?
Thanks in advance for reading,
W
I'm able to buy a large quantity of X2 type 10% (yellow) capacitors. I intend to use them in my (pre-)amplifiers for a audio mixer.
The question I have is of the soundquality will be effected negative? Does anybody have experience with these types in audio equipment?
Thanks in advance for reading,
W
Last edited:
They will work, but I would avoid using them for other applications than their initial purpose, especially in a preamp:
First, these caps are relatively bulky, because they need to have a size equivalent to ~a 1000VDC part.
In a preamp, 63V is already overkill, and bigger caps will catch more easily hum and noise caused by electrostatic interference.
You might need an individual screen in some positions, like a mic or RIAA input.
Another reason to avoid them is that they are safety caps, meaning a shallower metallization, and higher losses than a regular PP.
If you attempt to use them in a resonant converter for example, they will fail instantly and spectacularly.
In a preamp, the effect will be more subtle: nil for coupling caps, noticeable for bypass caps, and also detectable in some active filters, because of the lower Q.
I never said anything else, BUT there are different grades of metallization: in order to ensure a safe self-healing process, the metallization of X-type caps needs to be lighter than regular, general-purpose types.
For high power application, it is the opposite, and for really high power, you need a foil type.
All the Carli caps I've used (And Tenta, JURCC) have been MKP. The size of modern X2 caps is small, too.
If you need convincing, measure a X-cap that has been on duty (direct, permanent across-the-mains application) for 5~10 years: it will generally have a much lower value than its nominal one, sometimes as low as 10 or even 1%.
The reason?
The self-healing process has worked, and has vaporized almost all of the aluminum metallization.
Of course, in a "gentle", audio application, nothing of the sort will happen, but it shows that the metal layer is deliberately made fragile, to keep things under control.
If you use a regular 630V or 1000V DC PP cap as a substitute for X-caps, it will fail dead short at one time or another.
Morality: use the right part for the job, do not improvise.
The reason?
The self-healing process has worked, and has vaporized almost all of the aluminum metallization.
Of course, in a "gentle", audio application, nothing of the sort will happen, but it shows that the metal layer is deliberately made fragile, to keep things under control.
If you use a regular 630V or 1000V DC PP cap as a substitute for X-caps, it will fail dead short at one time or another.
Morality: use the right part for the job, do not improvise.
If you can tell the difference between these and Orange Drops, I'd be surprised.
There is nothing wrong with these for audio coupling at all.
MKP Safety Capacitor X2 275V 0.1uF/100nF/104K/0.22/0.47uf/220nf/330nf/224K/474K | eBay
There is nothing wrong with these for audio coupling at all.
MKP Safety Capacitor X2 275V 0.1uF/100nF/104K/0.22/0.47uf/220nf/330nf/224K/474K | eBay
I think this needs some clarity. Metallized polypropylene caps will self heal, even in the audio variety. It is not common for these to fail as a short. If these caps you speak of are film and foil, then yes- those fail as a short due to no self healing properties.
Later,
Wolf
If I had them in front of me, I could measure them, and I would certainly see a difference.
That said, for coupling applications, it would make no difference whatsoever, except a X-cap will be larger than a 63V part, and will catch more hum/interference.
I didn't say otherwise: most metallized caps, including PP will
generally self-heal when overstressed.
Generally, but not always, which is the reason for the X-grade: a standard cap may heal on 49 events, then fail the 50th time, which is not acceptable for a safety cap.
To reduce the risk of catastrophic failure, the metallization is made deliberately thin.
That said, even X-caps can sometimes (rarely, fortunately) fail in a catastrophic manner: I have seen a few spectacular examples
This is true, I'm a tube guy so 63V wouldn't cut it in the first place... The X2 caps are rated to 275VAC so at least 400VDC.
For tube circuits, the differences mostly vanish: because of the higher voltage level, and the higher impedance level.
I do not know in which category the OP falls, but in general, the advice of using the correct part for a specific job still holds: even for tube circuits, you do not know for sure what is the DC rating of a X-cap (it is sometimes specified, but rather rarely): you know that it has to be greater than 275*sqrt2, but that's about it.
In fact, the DC voltage rating is generally comprised between 700 and 2500V, but it is defined very differently from regular caps: when the upper voltage limit is reached, there are large numbers of flashover events that decrease significantly the capacitance, much more than the tolerance printed on the cap.
Of course, if you absolutely feel you have to use X-caps for other tasks, you are free to do so, but "naive" members posting questions should be warned about the objective consequences of such a choice.
I do not know in which category the OP falls, but in general, the advice of using the correct part for a specific job still holds: even for tube circuits, you do not know for sure what is the DC rating of a X-cap (it is sometimes specified, but rather rarely): you know that it has to be greater than 275*sqrt2, but that's about it.
In fact, the DC voltage rating is generally comprised between 700 and 2500V, but it is defined very differently from regular caps: when the upper voltage limit is reached, there are large numbers of flashover events that decrease significantly the capacitance, much more than the tolerance printed on the cap.
Of course, if you absolutely feel you have to use X-caps for other tasks, you are free to do so, but "naive" members posting questions should be warned about the objective consequences of such a choice.
Totally agree, sir!, and that's why I was asking. Again, many thanks for the advice and the explanation!
Anyway,... Did I wrote that I can get my hand on a large amount of MKP 5% 400V... capacitors
= I will go for that!W
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