PRE II conversion

[Cyprus Martin]

I’ve decided to convert my PRE II to the Cathode Follower version, I’ve got all the relevant instructions but the bit at the bottom of the page regarding the changes that need to be made to the PSU II has been torn off the bit that’s missing is about what to bypass ZD1 with. I seem to remember that it’s a capacitor but what value I haven’t a clue neither as to what sort it is, I presume an electrolytic but I would appreciate any help. I have quite a lot of bits in my spares box which I would like to use up so I may be that the value of the capacitor is not critical.

[Greg.]

Full instructions are in the FAQ including the detail you require.

http://www.world-designs.co.uk/forum...read.php?t=144

The schematic is now missing because it was originally hosted by Photobucket.

[Cyprus Martin]

Thanks for that Greg, it's so long since I was last on here I forget where things are.
Regarding the .1uF 400v capacitor does it need to be an electrolytic as I don't have one in my spares box but I do have others and do you know if the value is critical?

[Greg.]

I can’t remember exactly what I used but I suspect it was an Arcotronics polypropylene from Maplins. Their component stock is pretty dire these days, however, this would do you well imho. John or Richard might like to chip in with a more intelligent option.......

https://www.maplin.co.uk/p/lcr-audio...apacitor-vm87u

[bob orbell]

Hi Martin, a polyester will do fine, do not use an electrolytic. I have lots here but I assume you are not in the UK, if you are, PM me. BOB

[John Caswell]

Hi all,
As Bob says not an electrolytic. You can use the Soniqs from Matthew, which are very good "Orange drops" BC 468 series, MKT1813 series, Russian PTFE types, or any good capacitor except PIOs (Paper in oils) as they tend to leak (electrically - not oil) after a time, possibly due to heat.
I have just had to replace 4 of them in brand new a high end amplifier for that very reason.

John