I asked a similar question. mrfeedback supplied his observation.
http://www.diyaudio.com/forums/showthread.php?postid=82690#post82690
http://www.diyaudio.com/forums/showthread.php?postid=82690#post82690
Thank you Ciclotron ,
I can buy a couple of hundred from a banckrupcy store at very low prices ( 60uF/400V at 0,5 $ for example ) and it would be very good if I can use this capacitors at Sound Reinforcement Crossovers .
I can buy a couple of hundred from a banckrupcy store at very low prices ( 60uF/400V at 0,5 $ for example ) and it would be very good if I can use this capacitors at Sound Reinforcement Crossovers .
Hi,
This one looks very similar to the Comar ones and is probably the same:
http://www.comarcond.com/home.html (Italian only)
These are primary made for mains use at 50/60 Hz. Most modern ones are polypropylene capacitors although paper ones are still made. They can handle high power and have low losses. But don’t know how they perform at high frequencies. I have used 50uF ones for a flash unit.
Probably they will perform excellent in a crossover. These are definitely much cheaper than “audiophile” ones, mainly because profit margins are much lower and they are made in huge quantities.
For a 50uF/450V PP motor capacitor I paid around $15,- Brand new from stock.
Note that these are rated at AC. A 400V one can handle 600V DC and some are rated 800V short peak. Also nice for tubies. 😉
This one looks very similar to the Comar ones and is probably the same:
http://www.comarcond.com/home.html (Italian only)
These are primary made for mains use at 50/60 Hz. Most modern ones are polypropylene capacitors although paper ones are still made. They can handle high power and have low losses. But don’t know how they perform at high frequencies. I have used 50uF ones for a flash unit.
Probably they will perform excellent in a crossover. These are definitely much cheaper than “audiophile” ones, mainly because profit margins are much lower and they are made in huge quantities.
For a 50uF/450V PP motor capacitor I paid around $15,- Brand new from stock.
Note that these are rated at AC. A 400V one can handle 600V DC and some are rated 800V short peak. Also nice for tubies. 😉
Re Motor Cap
If you have the equipment do a frequency response sweep similar to that of circlotrons microphone calibration procedure.
It will cost you one cap some time on your computer and you will have a definitive answer.
On the construction of the cap itself it will probably be much more rugged than your garden variety film cap due to the voltage and high surge current requirements necessary in AC motor starting.
It's time to get your feet wet friend.
If you have the equipment do a frequency response sweep similar to that of circlotrons microphone calibration procedure.
It will cost you one cap some time on your computer and you will have a definitive answer.
On the construction of the cap itself it will probably be much more rugged than your garden variety film cap due to the voltage and high surge current requirements necessary in AC motor starting.
It's time to get your feet wet friend.
I use some kind of Motor type MKP 420 Volt for my
mids dome. They are oil filled and sound better than the
audyn cabs i had in before. But the burn in was hitting
my nerves. They sounded different nearly over 2 weeks of
listening until a friend gave me the tip to run them on
220v~ from the plug for a while. I loaded them about
half an hour until they became warm. Now they don´t change
the sound no more and i am very pleased with it.
mids dome. They are oil filled and sound better than the
audyn cabs i had in before. But the burn in was hitting
my nerves. They sounded different nearly over 2 weeks of
listening until a friend gave me the tip to run them on
220v~ from the plug for a while. I loaded them about
half an hour until they became warm. Now they don´t change
the sound no more and i am very pleased with it.
Attachments
Cheap at twice the price
At 50c each, you can hardly go wrong. They'll certainly be good enough for sound reinforcement, and rugged too. Go for it - get your feet wet!
At 50c each, you can hardly go wrong. They'll certainly be good enough for sound reinforcement, and rugged too. Go for it - get your feet wet!
I'm not convinced of the need to "burn in" the caps, but if you do decide to stick them across the mains, then 1uF = 3183 ohms at 50Hz so you can't just stick an unlimited amount across the line because it will pull way to much current. While you are doing this, see if your electricity meter goes backwards. There are quite a few urban legends about this sort of thing. 😉
Hi Circlotron,
it is only 15üf together. I didn´t believe in burn in as you
until i used these caps. The mids i used these parts with where
different from day to day - after the plug they didn´t change anymore.
Don´t know why, but this is what my ears tell me!
it is only 15üf together. I didn´t believe in burn in as you
until i used these caps. The mids i used these parts with where
different from day to day - after the plug they didn´t change anymore.
Don´t know why, but this is what my ears tell me!
NO... NO... most emphatically NO!
You cannot run a watt/hour meter backwards with a capacitor, this is urban legand. Most any foolishness you try only makes them run faster..... not slower. They can be made to run backwards via co-generation, but that's another topic!
You can however hit resonance and cause some interesting and exciting side effects by careless experimenting with LC networks across power mains. Be careful!
Cyclotronguy
You cannot run a watt/hour meter backwards with a capacitor, this is urban legand. Most any foolishness you try only makes them run faster..... not slower. They can be made to run backwards via co-generation, but that's another topic!
You can however hit resonance and cause some interesting and exciting side effects by careless experimenting with LC networks across power mains. Be careful!
Cyclotronguy
I didn't really think so but I had never tried it myself so I could speak with any authority. One thing I have wondered though is how well does a watt-hour meter measure half-wave rectified AC? Not legal in most places though. Electrolysis etc.
Hmmmmm. Don't know the answer to that one!
Watt/Hour meters usually are not too sensitive to VAR, where-as the transformers are. This is why the power companies hate lagging or leading power factor..... they don't get to charge you for it!
I'll cast about in the dark dusty corners for a meter and give this a test.
Cyclotronguy
Watt/Hour meters usually are not too sensitive to VAR, where-as the transformers are. This is why the power companies hate lagging or leading power factor..... they don't get to charge you for it!
I'll cast about in the dark dusty corners for a meter and give this a test.
Cyclotronguy
Test motorrun caps Tony Gee
I did send Tony Gee some motorruncaps and he did test them.
- Ducatie
- INCO
See the results on his internet side:
http://home.zonnet.nl/geenius/Cap.html
You also find very nice speakerdesigns
I did send Tony Gee some motorruncaps and he did test them.
- Ducatie
- INCO
See the results on his internet side:
http://home.zonnet.nl/geenius/Cap.html
You also find very nice speakerdesigns
I remember that motor caps were quite fashionable for use in crossovers during the seventies, while electrolytics were regarded as a no-no already back then.
I once "inherited" some paper in oil caps rated at 400 Volts from an old relay-based telephone exchange. These sounded also very well in crossovers. Some months ago I went up to the attic to get some of them for a quick trial set-up of a crossover and had to recognise that some of them were leaking. I think I will have to get rid of them since they might use some type of oil that is a potential health hazard.
I don't know what type of oil(s) is/are used in modern motor caps, maybe the dangerous ones are now banned.
Regards
Charles
I once "inherited" some paper in oil caps rated at 400 Volts from an old relay-based telephone exchange. These sounded also very well in crossovers. Some months ago I went up to the attic to get some of them for a quick trial set-up of a crossover and had to recognise that some of them were leaking. I think I will have to get rid of them since they might use some type of oil that is a potential health hazard.
I don't know what type of oil(s) is/are used in modern motor caps, maybe the dangerous ones are now banned.
Regards
Charles
Motor run caps are excellent for audio purposes. Naturally there are bad quality motor run caps out there as well, but any of the big brands are of very fine quality, as they would blow in their intended application if they were not.
A brand I can recommend is Comar, they are cheap and good quality.
Theese days a motor run cap (the good ones that is) is a dry pp film cap. The kick a$$ versions are nitrogene filled. Those are though usually found in power correction networks and are of a substantial physical size. (see link)
I recently bought a few of theese to experiment with, could be the ticket to ultra low loss caps.
http://www.briangt.com/gallery/magura/PICT0001
Magura🙂
A brand I can recommend is Comar, they are cheap and good quality.
Theese days a motor run cap (the good ones that is) is a dry pp film cap. The kick a$$ versions are nitrogene filled. Those are though usually found in power correction networks and are of a substantial physical size. (see link)
I recently bought a few of theese to experiment with, could be the ticket to ultra low loss caps.
http://www.briangt.com/gallery/magura/PICT0001
Magura🙂
I've used cheap polypropylene motor capacitors in passive crossovers before and they worked fine. They're cheap and have reasonable tolerances. Surely a good compromise between electrolytic and normal polypropylene caps.
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