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In Reply to: Re: Which 519 ? posted by Aleks on March 6, 2007 at 20:36:34:
Hi Aleks,
I didn't look at those links but, when i was looking for caps for the front end supply, there were no black gates of suitably high voltage and the correct value to use. The FK black gates are best suited to power supply usage, but top out at 350v if I recollect correctly, I did use some of these elsewhere in the power supply, but the sound of the amp is audibly changed by the value of the front end supply caps and their value, larger caps can give it quite a bit more bass ( I tried up to 47uf ) but with some loss of speed, i tried a few types and values and currently am using the specifed value according to the EAR schematic ~22uf, the issue was that- at the point of turn on, there is a big spike in voltage before the tubes have warmed up, this momentarily exceeds the rating of the supplied caps each time the amp is powered up, leading to a break down of the dielectric. Using 450V rated 104 deg. caps is the minimum I would replace them with, 500V electrolytics would be ok. But even better are poly caps and Mundorf make a very compact series called "TubeCap" they are much higher voltage again, have excellent characteristics, are cheap and come in suitable values to use (20uf, 750V) or even 2 x 10uf if you like..or 1 x 30 or 40uf if you're so inclined..!
You can buy them here: http://www.hificollective.co.uk/components/m_cap.html
(I think you were in the U.K, but you can get them from most decent component suppliers)
BTW: the caps I'm referring to replacing, are located at the back end of the EAR869 circuit board, near the rca input sockets..check if you see any signs of leaking.. brown deposits around the point where they meet the circuit board...either way the mundorf will be a good improvement here..have fun :-)) Did you source any EL 519's tubes yet ?
They too will play a big role in the sound if yours are getting old, consider these:
http://cgi.ebay.co.uk/2-x-EL519-Philips-Amperex-1-NOS-1-used-1-neu-1-gebr_W0QQitemZ260092236263QQihZ016QQcategoryZ38692QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
I bought a NOS pair from this seller, he is a good eB@yer and still keeps in touch with me, Tell him coolhand mentioned him to you, he might give you a buy it now price, he's very reasonably priced ! (btw:I have no connection other than a happy customer..)
Follow Ups:
Hi coolhand, I am a bit confused - you said that EAR schematic had 22uf front end supply caps. In my amp there are four small 4,7uf 450V Marcon caps at the back end (and two 22uf 250V in the centre) I thought about TubeCaps but the lowest capacity they had was 10 uf (with 1000V) and the next was 20uf 700V. Do you think I can use them to replace 4,7ufs?
I am in London, so by the end of the day I can take it to Tim for a service, but I guess it would not be as much fun (in terms of both fun and money :-)
I have sourced some Ei 519s, but thanks for the link, I'll have a look.Rgds, A.
Yes, Tim did put in 2 x 4.7uf (= ~10uF) per channel, but on my schematic he clearly had 22uf per channel. I imagine that he might of found 10uf to increase the apparent speed and tightness (slimmed it up !) of the bottom end, not sure really...as I mentioned adding capacitance here increases the bass but the more you add starts to slow down things, two smaller caps can be better than one larger cap in a power supply also, but for what it's worth I found that a single 22uf cap as specced in his schematic lost nothing in speed but gained a tad more balls at the bottom end.
47uF really beefed it up with a slight trade off in speed, I settled with a 20uf Tube cap...either way you can try a few to form your own opinion. As I mentioned either a decent 450v rated 22uf electrolytic, a single 10, 20, 0r even two 10 or 20uf Tubecaps would be great. You wont do any harm trying the any of the above combinations, do pay attention to polarity though if using electrolytics.
Thanks coolhand, you've got my mail.
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