diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Tubes / Valves (http://www.diyaudio.com/forums/tubes-valves/)
-   -   Replacement capacitors? (http://www.diyaudio.com/forums/tubes-valves/24108-replacement-capacitors.html)

eeka chu 12th December 2003 08:41 AM

Replacement capacitors?
 
Hi,

Does anyone know of a good replacement for Elna's Cerafine capacitors?

I had a search on google but didn't find much. I am really interested in their large can Cerafines, the mF ratings used for high voltage power supply filters; for valve plates.

I know Black Gate make a few power tank capacitors but their maximum rating is something around 220uf at a few hundred volts.

I am really tired of AC hum now!!! :D

Thanks!
John

roddyama 12th December 2003 05:22 PM

Hi John,

I'm moving you to the "Tubes" forum for a better chance at a response.:cop:

Cobra2 12th December 2003 05:31 PM

What size / rating are you looking for?
I have some RIFA (PEH169) 220uF / 350V lying in my bin, no use for me as I never touch tubes...:dead:

ArneK

eeka chu 12th December 2003 08:06 PM

Many thanks to you both!

Cobra, no tubes...?! :bigeyes: :D

It's kind of you to offer but I was looking for a long term supply of them really. I was thinking of selling a particular amplifier and could use a direct replacement that I could buy in bulk amounts. I have read a few notes buy audiophiles who are having trouble finding a replacement themselves.

It seems odd that Elna would withdraw this line given it's apparently market. :xeye:

Brett 12th December 2003 11:00 PM

Quote:

Originally posted by eeka chu
It seems odd that Elna would withdraw this line given it's apparently market.
In terms of their other lines, it was likely a miniscule market.

Besides, I'm wondering why you need such large amounts of capacitance? If it's to remove hum, you have a poor design. Bigger caps usually sound like crap, esp electros.

The best suggestion I can offer are the Panasonic TSUA/TSUB or FC ranges. Aerovox also make some that might be suitable.

fdegrove 13th December 2003 01:47 AM

Hi,

Quote:

Bigger caps usually sound like crap, esp electros.
Yes, but Joules are hard to beat especially when they're drawn from quality film caps or ASC oilers.

Capacitor values for PSUs are voltage related: the higher the V the less C is required.

Class of operation is another factor but quality caps hurt neither.

Cheers,;)

eeka chu 13th December 2003 10:59 AM

Quote:

Originally posted by Brett


In terms of their other lines, it was likely a miniscule market.

Besides, I'm wondering why you need such large amounts of capacitance? If it's to remove hum, you have a poor design. Bigger caps usually sound like crap, esp electros.

The best suggestion I can offer are the Panasonic TSUA/TSUB or FC ranges. Aerovox also make some that might be suitable.

Thanks for the suggestions, I'll check them out.

The caps are for the Pi filter after an induction choke. It's a simple transformer, 1N4007 bridge, cap, filter, cap arrangement. I am looking at the idea of regulating the voltage as well but that is really to the side for now; besides, I would question if it's really necessary in such an amplifier.

Black Gate's 220uf + 22ouf capacitor looks like it will do a good job at filtering the rectified DC. From what I've read, Black Gate's perform almost without competition, but it's also quite expensive; about 60 pounds per capacitor, I think that would be over a hundred dollars.

Also, I am concerned about surge currents when the supply is turned on. The choke will be rated for a maximum of a 200ma, but a large enough capacitance at 170 - 200v I suspect may be too much for the windings of the transformer and choke. I was having a look at it in Duncan's PSU calculator and was getting closer to a 1 amp peak. While the peak is only for part of a second, it is still a substantial peak in comparison to the winding ratings. To counter this, my initial thoughts where to just fit a NTC thermistor in series with the output of the transformer for a cool soft start mode. :)


All times are GMT. The time now is 07:32 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2