I'm trying to find some 75uf and 22uf 100v Bi-Polar or Non-Polar electrolytic capacitors. I've tried RS Components Australia, Digikey Australia and Mouser Australia with no luck, any ideas where I can get some of these? They are for a speaker crossover.
In 100v? Parts express.
But in those values I would look for polyester or even better, polypropylene caps.
But in those values I would look for polyester or even better, polypropylene caps.
Hi redrooster,
Often, large nonpolarized electrolytics are hard to find. One very common solution is a pair of conventional electrolytics of twice the capacitance and the same working voltage, series-connected, + to + or - to -. The penalties - you may end up paying more than twice the money and using more than twice the volume.
Ron
Are there any down-under speaker component dealers? Instead of looking at general parts houses like Mouser or RS, try speaker specialists. Even a good reconer ought to know where to source speaker parts.
For the 75uF you can get a great film cap from ApexJr on eBay for about $5 plus shipping. It’s way overkill at 600v but that doesn’t matter. They are larger that an electrolytic cap but way better and will never go bad. For the 22uF look at Solen film caps, they are decent quality and widely available. All are nonpolar.
Other penalty at low voltage and low wattage, back to back 10000 uf capacitors series a SP2-XT sounded like ****. I tried it at the 1/8 watt I typically listen to my 100 db 1w1m speakers. The chemical events of crossing zero are blatant and annoying. If by contrast you were using the speakers to blast a disco hall at 300 watts, you'd probably never hear the difference.
Thanks for all the ideas, suggestions and tips fellas! I should have added that I have a variety of ''Erse'' branded,100 volt, axial +/- 5% crossover caps 8uf, 12uf, 17uf, 20uf, 22uf, 25uf, 30uf, 40uf, 50uf, 56uf, 65uf, and 100uf. Can I get away with a few microfarads either way of 75uf? If not I will use 75uf polypropylene motor run capacitors. I have used this type before in a pair of Made in England, Quasar QS1 studio loudspeakers from the 1974 era, they work and sound great.
You have 25uf and 50uf in your inventory list. One of each wired in parallel, et voila 75uf.
RIP Erse, he just passed away of brain cancer in his 50s. His stuff was better than average. Try the motor run cap, some people love them. If you don’t do the 25+50 in parallel.
Yes, I read about Mr Erse passing away the other day, it's so sad, I hope his family and or the employee's continue with the business? I tried 25uf and 50uf in parallel but it read 89uf on my Fluke 87 v DMM? I will keep trying with other values to see what I get but it looks like I will be going with the motor run capacitors which are in my experience the best and cheapest anyway.
My heartfelt sympathy for Mr. Erse's family and employees. I don't know enough about him, but I'll check. Our children are his age.
I had an oil cap go bad recently, but it was a Start cap in our air conditioner. Turns out it wasn't bad after all. It was conducting crud on the leads from being outside. I had the repair tech leave it with me. I don't work on air conditioners or cars anymore. Shouldn't say that, since I modded our HVAC controls a couple years ago, while calibrating and labeling EVERY thermal device in our house, using a pair of 1N914s and a $5 Chinese DMM as my ultra-sensitive DIY precision frigorific mixture differential thermometer.
Generally, electrolytic tolerances are a sloppy +/- 20%, especially on the low side and worse on the high side. If a cap is better, say +/- 10%, you'll never hear the difference. If you're concerned, I'd be prone to test the frequency response with a very expensive Radio Sack Sound Level meter's analog output on an o'scope or a sound board or use a couple of inexpensive (US $3) electret mics and average their readings. You can use speakers as mics, especially if they're calibrated, using reciprocity.
I once worked for an MIT PhD EE, who did Post Grad work at the original Gaithersburg Maryland National Bureau of Standards. I'll never forget his telling me if they didn't put a pressure equalizing pinhole in the mic's diaphram, most electrets would be flat down to the milliHertz range. A lot of DIYers put electrets in low-leakage boxes to listen for distant aircraft and earth tremors. I'll have to look for those Forums.
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