I got 10 of these 5nF capacitors very cheap:
It says 'DIN41161' and if I look that up I see it is a 'paper capacitor'.
They must be very old, however the first two measure ok, didn't check them all. And they do not seem to be used.
Are they still usable for audio? How is the quality of a paper capacitor compared to say, a film capacitor?
It says 'DIN41161' and if I look that up I see it is a 'paper capacitor'.
They must be very old, however the first two measure ok, didn't check them all. And they do not seem to be used.
Are they still usable for audio? How is the quality of a paper capacitor compared to say, a film capacitor?
I think you will find they are ceramic capacitors, or "condensers" as we used to call them.
Paper In Oil are very old technology and prone to be electrically leaky. Ceramic capacitors, on the other hand, are generally reliable but can be moisy.
A capacitor is a capacitor. Little difference if the correct value is used.
Paper In Oil are very old technology and prone to be electrically leaky. Ceramic capacitors, on the other hand, are generally reliable but can be moisy.
A capacitor is a capacitor. Little difference if the correct value is used.
Is there more writing on them? They could be temperature-compensated. And they will probably be very low in value, <= 1nF, so not much use for audio.
Thanks. We still call them 'condensatoren' in Dutch. I will try to find more information on them or just try to use them, carefully.
Paper is a hopeless dielectric in practice, over time it absorbs moisture, changing the capacitance value and increasing the loss-factor and leakiness, and also oxidation can occur degrading the dielectric with similar issues. That's why its not used any more.
These ones have an hermetic encapsulation, meaning they probably aged more gracefully than others
Together with oil, paper is still the preferred dielectric used in almost all of the transformers in our grid. From 500 kV down to 10/0.4 kV.
Life expectancy is at least 50 years, and you can have samples of the oil analysed for certain chemicals that predict end of life (paper degradation).
Modern production processes still use paper but have a special process extract almost all the water vapour before the transformer is filled with oil. This way a life expectancy of 80 years is possible for transformers.
As for these paper in oil capacitors, put them on an LCR meter which also measures D-factor. You'll know soon enough if they are still usable or have gone leaky (by that I mean DC leakage). I know some paper type caps (wax type) go acidic over time and start to become resistors instead of condensors (to use the old terminology).
Life expectancy is at least 50 years, and you can have samples of the oil analysed for certain chemicals that predict end of life (paper degradation).
Modern production processes still use paper but have a special process extract almost all the water vapour before the transformer is filled with oil. This way a life expectancy of 80 years is possible for transformers.
As for these paper in oil capacitors, put them on an LCR meter which also measures D-factor. You'll know soon enough if they are still usable or have gone leaky (by that I mean DC leakage). I know some paper type caps (wax type) go acidic over time and start to become resistors instead of condensors (to use the old terminology).
For industrial sized caps you can afford to manage the degradation like this, in order to reduce total costs, but we are talking small components without oil monitoring ports(!), where the cost of precautions to protect the paper is greater than the cost of switching to PP, for instance. Anyway non-linearity isn't such an issue for mains power factor correction or mains snubbing applications as it is for audio, the bulk price matters more.
That's definitely going to help, but not all "hermetic" encapsulation can prevent acid ingress, free protons are very mobile in many solid materials.
My paper capacitors from GI made in 1961 were wax sealed. They measured fine in 2015, except the one where the wax case was burnt open by the installer. Unfortunately the burn was hidden by the installer, and that was the last one I replaced. Preamp had a channel imbalance caused by that one capacitor. The polyester replacements did not sound as good. Excess treble. The circuit was designed for paper. I parked the PAS2 in the attic and do not use it. September 2020 a local burglar hauled it to his fence for $.005 on the dollar cash value
The unsealed mallory paper capacitors in hammond organs prior to 1966, those have changed in value about 20-40%.
You will not find diy plans in 2024 designed for paper capacitors. Exception, some guitar amps of historic design still use them.
The unsealed mallory paper capacitors in hammond organs prior to 1966, those have changed in value about 20-40%.
You will not find diy plans in 2024 designed for paper capacitors. Exception, some guitar amps of historic design still use them.
Most untrue, without going into scope of what you can hear or not. You ought to put in other specifications into perspective. Use y5u and c0g in signal chain. Same value, report here what you see on osciloscope, and check value of said capacitoe (you can notice sound wise too but lets leave it out). Then to make matters worse, tap on the device, which happens in real life "as that bass drops". Now try to decouple analog chip with low esr high current leakage capacitor, and do the same with low current leakage cap. There are rules to this game, some more strict some not.
I hesitate to post this for obvious reasons and unfortunately I do not have the room for equipment to prove that a ceramic capacitor sounded worse than non-ceramic ones in my 3HPA headphone amplifier (if proving that is possible), but I always try to be self aware of bias, placebo effect or how you want to call that (if proving that is also possible). Nevertheless I immediately heard the harsh upper frequencies when I used (old) ceramic capacitors at the input. That disappeared after I installed capacitors of a different type.
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Do you know what kind of ceramic capacitors those were? Unlike class 1, class 2 and class 3 ceramic capacitors can distort like hell when there is a substantial signal voltage drop across them.
I used this type, very old:
I used 1nF at the input to ground in a headphone amplifier made of bipolar transistors (the 3HPA) to solve the problem of a scratchy volume pot. That it did but in exchange the amplifier sounded really terrible. You are probably right! 👍
Its worse than you imagine, high-K dielectrics seem to have cross-over distortion... Undeniable if you plot the residual, so even small voltages cause high levels of distortion.
@widea The photo looks like a single-layer NP0 capacitor from Philips. Philips always made the class 1 capacitors grey, I don't think any other company did that. The black stripe indicates NP0, which already implies it is class 1. They are actually very good, but I've never seen one with a value above 120 pF.
I therefore guess your 1 nF capacitor was tan coloured and had a yellow or green stripe (or no stripe at all if it wasn't from Philips). Those are class 2 (a.k.a. high K or high epsilon_R).
I therefore guess your 1 nF capacitor was tan coloured and had a yellow or green stripe (or no stripe at all if it wasn't from Philips). Those are class 2 (a.k.a. high K or high epsilon_R).