Input Cap upgrade.

[Stream]

Hello.
I have Cambridge Audio Azur 340 amp. I have already replace almost all power supply electroytic caps from stock noname to Panasonic FM\FC, diodes to MUR860, half part of ceramique to epcos mkt. Now it's time to swap opamps and coupling caps...

---------------------------------
So... Input(coupling) caps.
Stock caps are 10uf polar electrolytics. R = 22k.

I haven't got much money to make some experiments, so I want You to tell me Your advice...

I can place here Wima MKS2 MKT but only 1uF. It will get about 7hz HPF filter freq, but As i know it's recommended to have this value set to ~1-3Hz.

Also i can buy Black Gate PK 50V 3.3 uF for only 1 Eur\pcs. If it's good deal?

And the third: buy some (2.2-4.7uF) polyproplene cap. No doubt PP has the "best" sound, but it has higher price, and big size and so it will have too long leads. I think it's not good.

Here is piece of shematic:
http://img261.imageshack.us/my.php?image=inbufnm7.png
http://img154.imageshack.us/my.php?image=powereo3.png

Thanks.

[pacificblue]

Aren' t the WIMAs and Black Gates also PP caps? Metalized polypropylene foil that is.

You will probably gain more from using the correct value than from using a different brand. So, if you change the brand, it should be the correct value as well.
You will often find recommended to connect a film cap in parallel to the electrolytic. Then the value is not so critical, because it will only get higher, whichever you choose from your list.

What effect did you achieve by replacing the ceramics with MKTs? And what was their function in the first place?

[AndrewT]

as a first stage add a 1uF MKT or MKS (metalised film) in parallel to the electrolytic. These are quite small and quite cheap.
Tell us how it sounds.

[mikesnowdon]

3.3uF of wima MKS2 will do fine, better than any lytic and no loss of bass or weird characteristics. I know this as I have tried it. Dont get too paranoid about mathematics here. 3.3 to 10uF should be ok.

[Stream]

3,3uF Wima from Ebay (a pair of wima ~ 5$ + 10-15$ shipping) cost aprox. like cheap polypropylne (a pair of PP ~ 10$ + 7-10$ shipping) from one of russian store... So I thnik better to have long leads, than worse dielectric?

BTW about advice to replace with stock values... I can't understand what for using 10uF in this sheme. I think it's just standart CHEAP value, so many low cost amp has them...

[pacificblue]

Originally posted by Stream
3,3uF Wima from Ebay (a pair of wima ~ 5$ + 10-15$ shipping) cost aprox. like cheap polypropylne (a pair of PP ~ 10$ + 7-10$ shipping) from one of russian store

Wow! Here you can get them for 0,58 € a piece (MKS-4 100V). Shipping is of course an issue, if you only buy a few capacitors.

[AndrewT]

Originally posted by pacificblue

Wow! Here you can get them for 0,58 € a piece (MKS-4 100V). Shipping is of course an issue, if you only buy a few capacitors.

buy me 22 off.
Send 20 to me and the other two to Stream.
Email with payment details.

[mikesnowdon]

He really wants MKS2 (3.3uf) or MKS2-XL (10uF) as they fit the board better.

[Stream]

I found MKS2-XL 10uF for about 8$\2pcs + 12.5$ shipping.
Thinking on it...

[mikesnowdon]

Maybe Pacificblue can get em cheaper in Germany?