Good replacements for Black Gate NH caps in tube amp?

[renton1]

Hello,

I´m just buliding the following amp and can´t get the needed Black Gate NH (100uf/160V) caps. http://www.triodedick.com/ceasar_2/c...versterker.GIF

Positions are C6 & C7.

Are there some good non polarized replacements available or do some shops still provide the BGs ?

Many thanks and best,

Rents

[indianajo]

Knowing what continent you are one would help the helpers. Non-polar electrolytic caps are getting rare in the US, newark.com doesn't have them. They do list some "xxx V" parts, but when they come in they have a plus marked on one end. Just a case of United Chemicon saving money on ink. Mouser.com has a selection of NP capacitors, but you have to click capacitors and aluminum electrolytic before the computer will let you see them. I believe they had 100 uf and 220 uf last time I looked, but you will probably have to go up on the voltage. FIlm caps in the 50 uf size could be paralleled, but they come in a 660 VAC rating and are about 8 cm dia and about 15 cm tall. (genelec brand) I used some on my organ at 450 VDC.
As far as "black gate" I have never run across these anywhere among newark,mouser, tubesandmore.com, triodeelectronics.com. I look at package size (some are too tall), ESR, life ratings in hours, and leakage at end of life notes since some manufacturers allow worse performance at their quoted "end of life" test. Some countries of origin seem to have more "tolerance" of out of compliance products than others. I have been happy with the Japanese, Malaysian, Thai and US origin electrolytic capacitors I have been getting from Nichicon, Panasonic, Rubycon. I haven't bought any NP's yet. United Chemicon and CDE caps have been ******e in origin.

[sasha70]

Hi Rents, my understanding of this schematic is two polar capacitor connected in parallel in reverse polarity, to create non polar capacitor.
Regards.

[Greg Stewart]

The Black Gate N series was non-polar.

As a sub, I'd strongly consider DIY HiFi Supply's Obbligato PSU caps... see here:

Obbligato PSU Film 100uF 400V | Diy HiFi Supply

Greg in Mississippi

[renton1]

Mamy thanks for the answers.
I think, I´m going the obbligato route. Are the some suplliers out in Europe?

[SY]

Originally Posted by sasha70

Hi Rents, my understanding of this schematic is two polar capacitor connected in parallel in reverse polarity, to create non polar capacitor.

I don't think so. Not only doesn't that make a nonpolar cap, that will make an explosion.

No reason that you'd need a nonpolar cap in that position- the cathode never goes negative. Use a good quality polar electrolytic, preferably 105 degree rated. Bypass with a smaller film cap if that makes you feel better.