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K75-10 voltage

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Posted on September 14, 2016 at 18:00:06
banpuku
Audiophile

Posts: 957
Joined: January 19, 2006
Contributor
  Since:
March 30, 2017
I am looking at the Russian k75-10 250V. My circuit calls for 305V. Do these Russians caps have significant voltage headroom whereby I could go use them in my 305V circuit?

 

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RE: K75-10 voltage, posted on September 14, 2016 at 18:43:52
Blackdog
Manufacturer

Posts: 1165
Location: Ontario
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You want to put 305V on a 250V cap! The net result will in all likelihood be a shorted cap at best, and possibly a small explosion at worst.
I have used these Russian caps, and despite the so called experts hailing how good they are, I would not use them unless I had at least 25% voltage headroom. Too many failures when you approach their voltage limit.


Dan Santoni

 

Not necessarily., posted on September 14, 2016 at 22:50:40
Michael Samra
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Dan
The Russian FT2 teflons are rated at 200v and I have been using them for years without one failure..I use them in 600v applications all the time.

Look at my test results.It shows not one bit of leakage at 765vdc.

On the 630v rated k40y,I ran it up to 826vdc and I got about 75ua of leakage so that's a no no.

I'm sure he will be safe on the k75-10 at 100vdc over with no issues but I will test one tomorrow. Check out the link.

"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

You will be fine and I don't even have to measure it and here is why., posted on September 14, 2016 at 22:59:08
Michael Samra
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The voltage rating on the k75-10 is 250vac so can figure at the very minimum it's a 350vdc cap. I know this cap will easily do 450vdc without leakage.

"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

RE: You will be fine and I don't even have to measure it and here is why., posted on September 15, 2016 at 04:19:31
Blackdog
Manufacturer

Posts: 1165
Location: Ontario
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You are correct. I hadn't noticed they were rated in AC. They should be fine.
I still would not use them above about 350V though. Too many failures.
However I haven't used them in about 7-8 years as I don't trust them or like the fat sound they impart.



Dan Santoni

 

RE: You will be fine and I don't even have to measure it and here is why., posted on September 15, 2016 at 10:37:19
Michael Samra
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Posts: 35874
Location: saginaw michigan
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I still would not use them above about 350V though. Too many failures

I agree. You can use higher voltage on the teflons tho.

"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

RE: You will be fine and I don't even have to measure it and here is why., posted on February 10, 2017 at 02:14:44
jonny-
Audiophile

Posts: 117
Location: Lisbon
Joined: November 12, 2004
Dear Friends
Also have the same doubt. My tube amp at startup raises the tension to ~410V for about 20 seconds, then after the tubes start to conduct and lowers to lets say 190V. Do you PPL thing it is safe to use a K75-10 250Volts 50hz/AC here? Some say it“s times 1.4 the tention AC to DC, other say it even can go to times 2.4(???scary).
Tnx
Joćo

 

RE: You will be fine and I don't even have to measure it and here is why., posted on February 10, 2017 at 07:42:07
used-hifi
Audiophile

Posts: 529
Location: Surprise AZ
Joined: March 18, 2003
Just for Clairity Mikey...

What about the other Russian k40y-9? these only have a voltage on them not if they are AC rated voltage??


Thanks

Lawrence

 

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