Capacitor Question
- Thread starter Ron Resnick
- Start date
Thank you. Getting the capacitor to achieve the crossover point and slope I want is a fair concern.
The integration is settled in theory, as I am simply trying to replicate the slope of the stock high-pass filter.
That device is an answer to a vastly more complicated question than the one I asked in the opening post. As a philosophical matter I don't believe in adding active components and risk adulterating the sound when I know the slope I want and a single capacitor will do the trick.
I'm curious to know of your results. I found the cap in series as part of a first order (with the amp input impedance as the resistive load) too gentle of a slope to be effective towards ameliorating my room modes and would've required a starting Freq rolloff too high for me to be comfortable with (6DB / octave).
I also agree that adding a component (Wilson ActiveXO) in the signal path is not preferred, but I'm willing to give it a try as it's not too costly and looks to be a very high - quality unit (included with the WAMM Master Chronosonic speakers) with flexibility far above a cap in series.
Again, curious to read about your results, I'll share mine too.
Ron, I am puzzled you got several inputs on how to solve this easily, yet you dismiss them as wandering off topic. Good luck with this
Respectfully, I do not understand what you are finding to be puzzling.
The opening post question is: Who makes a high quality high-end audio capacitor with values of 2,700pF and 3,000pF and some semblance of consistency?
I am grateful to everybody who suggested particular brands of capacitors. That answers my question. I thanked these respondents along the way.
Conversely I find suggestions of brands of active crossovers to be inapposite responses to my question.
Maybe the problem is that you do not really understand what needs to be done. People tried to help you. It is pointless to chase tight tolerance capacitors without checking (and if necessary adapting) the input resistance. And with the adaption of the input resistance you could even work with the tolerances given by Duelund without compromising the filter accuracy. Anyways I assume somebody gave you the idea that you need this, maybe this person should help you with your questions
The only "problem" I see here is that you seem to be trying to make up a problem when I don't have a problem.
Again, I thanked the people who read and kindly answered my actual question.
I don't consider looking for better than a 40% spread to be "chasing tight tolerance."
I understand that methodology. I measured the amplifier's actual input impedance.
This is an incorrect assumption. I am experimenting with relocating the high pass filter in front of the amplifier rather than after the amplifier on my own initiative.
Ralph Karsten kindly confirmed the approach I proposed on my own initiative, and confirmed my calculated capacitor value.
So all is solved, perfect, sorry for chiming and and making a fuss about nothing. Maybe it would have been helpful if you stated all the things you have checked before hand that could have shortened this thread. Good luck with this endeavor
I'm not buying Russian these days.
From asking around apparently for these very low capacitance values there's not a lot of controversy about the sonic need for fancy capacitors. One friend recommends polypropylene. Jeff of Sonic Craft recommends RelCap RTE.
Once the fancy Duelund/Mundorf parameter is lifted, these capacitors are easy to find.
Thank you.
Actually you would support the Ukrainian but never mind
Well, the signal goes through these capacitors - they are in series with the input. If they do not matter, why would any other capacitor in our systems be relevant to sound quality?
I dislike the use the word "fancy" when applied to high-end components unless they come in a velvet lined box.
These brands have several class of components - your choice was "fancy", but surely Mundorf is not a "fancy" brand. They supply us with technical information, including measurements, and details about what we get from them.
It has an active low-pass filter in front of the bass tower. You don't necessarily need a second one in front of the amp in the signal path. I've described how I would do it. Well, everyone can do it as they wish.Ron this is quite easy and your are correct it needn't be over complex.
I tried to articulate it here- your are applying a simple 1st order filter to the input of the amp:
Capacitor Question
I tried to custom order 2,700pF and 3,000pF capacitors from Duelund, from its CAST copper line, for a DIY high-pass filter. Duelund says it cannot guarantee each capacitor any closer than 20% to the actual value requested. In theory I could have two capacitors that are 40% apart in value! I...www.whatsbestforum.com
This is not an active filter like @DasguteOhr suggests here:
https://www.whatsbestforum.com/threads/capacitor-question.41026/post-1061837
Here is a simple calculator- you can ignore the "L" for inductance, lets assume you want to filter to 80Hz on the input of your amp that has a 100K ohm input impedance
You would need a cap that is .019 mfd or nearest commercial value 0.022 is good enough for a first order filter
Reactance calculator R L C inductance inductor capacitance capacitor frequency - sengpielaudio Sengpiel Berlin
Reactance calculator R L C inductance inductor capacitance capacitor frequencyr - Eberhard Sengpiel sengpielaudiosengpielaudio.com
I found a discussion by the late Roger Modjeski on this exact topic that dispels the need for accurate 1% caps- btw Roger had no time for exotic capacitor material talk fwiw
link:
"A quick note on how to calculate crossover component values for 6 dB/octave filters.
C=1/6.3 x frequency x input impedance of amplifier (or thing following the filter). It's simple.
A customer requested a 600 Hz crossover at the input of an EM7 amp. Standard EM7 amps have 150K input impedance so the value would be 1.76 nanofarad (1760 pf). The closest standard value is .0018 uF. Anything from .0015 to .0022 would be fine. For gradual crossovers the value is not critical. The only place accurate (1%) capacitors are needed is in a RIAA network or an active filter. I find it amusing when neuoritoc audiophiles want to use a 1% capacitor where the value is approximate anyway. That's just plain silly.(more on this if you want)
He also asked about the RM-10 which has 100K input impedance. Most power amps are in the range from 15K to 150K ohms and you can usually check this by simply plugging an ohm meter into the input jack of the amplifier in question. If you get on OL on the meter or several meg ohms there is probably a capacitor in the input already and you have to get to the other side of that cap, measure the resistance and change that cap to the new value. That's all there is to it.
Any capacitor of any voltage will work fine. I would use a polypropylene or Mylar."
Good luck!
P.S
I like semi-active speakers. I do the same thing. Passive and active bass.
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Cause those are horrible? Imho of course, but still.
Talking of Ukranians, Abbas makes wirewound caps in the same range for his phono... just an idea.
Capacitor choice is very much system and taste dependent, perhaps a set of at least 5 different pairs is the minimum required to make a choice that is not severely compromised.
The capacitors take a really long time to sound good—at least 200 hours. Most people lack the patience.
and they are really big.
clarity cap same value
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Hi Ron,
Duelund is doing nothing wrong. These values are pico small, and they aren't setup for that with the way they make capacitors. The fact they can offer it at all is sort of impressive. Sadly it would be expensive in a silly way to buy dozens to match. On that note cheap capacitor meters work fine in general - enough to measure cables accurately that are in the two digit PF range.
Most "audiophile" capacitors in circuits and not crossovers tend to sound like HiFi. There are not many I can approve of for sounding right in a general sense and mostly only in a specific circumstance sense. But the value you're looking at opens up doors for other types of capacitors. Here's two capacitors that will likely work just how you want and the tolerances are so tight that it's up to you if you want to measure out matching as it's unlikely to be appreciable in any way. 2700pf and 3000pf . The only note is to avoid excessive heating when soldering; normal soldering works fine but lots of short interval reworks is not advised.
These two caps are on my short list of cost-no-object choices for an inline corner filter or anywhere I can get away with such low values. Silver Mica are not my preference, unnatural, and unpleasant unless paired with a very soupy tube amplifier that needs all the help it can get. I literally only use Silver Micas out of desperation and over certain other ity bity caps that are worse (sadly this does happen where there are just no options but it's rarely critical to the sound).
If you're wanting other recommendations feel free to reach out.
Duelund is doing nothing wrong. These values are pico small, and they aren't setup for that with the way they make capacitors. The fact they can offer it at all is sort of impressive. Sadly it would be expensive in a silly way to buy dozens to match. On that note cheap capacitor meters work fine in general - enough to measure cables accurately that are in the two digit PF range.
Most "audiophile" capacitors in circuits and not crossovers tend to sound like HiFi. There are not many I can approve of for sounding right in a general sense and mostly only in a specific circumstance sense. But the value you're looking at opens up doors for other types of capacitors. Here's two capacitors that will likely work just how you want and the tolerances are so tight that it's up to you if you want to measure out matching as it's unlikely to be appreciable in any way. 2700pf and 3000pf . The only note is to avoid excessive heating when soldering; normal soldering works fine but lots of short interval reworks is not advised.
These two caps are on my short list of cost-no-object choices for an inline corner filter or anywhere I can get away with such low values. Silver Mica are not my preference, unnatural, and unpleasant unless paired with a very soupy tube amplifier that needs all the help it can get. I literally only use Silver Micas out of desperation and over certain other ity bity caps that are worse (sadly this does happen where there are just no options but it's rarely critical to the sound).
If you're wanting other recommendations feel free to reach out.
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