capacitors for acoustica mods

[mega lord]

Hi eveyone,

This is my first post on this forum after getting bored with naim forum. After doing much research and learning to solder i am in the position to start replacing caps in my naim nac72, nap140, cd3.5 and hicaps.

I have found some of the caps recommended on the acoustica site (i.e Bc128, and oscon sp's) on the farnell site but i'm having trouble finding Elna slimics and evox-rifa mmk and smr.

On the farnell site they do stock Elna RE3-35V100M (10uf, 35V) aluminum electrolytics - are they the said "slimics" referred to on acoustica ?

I have found evox-rifa mmk 47uf, 63V on elfa site but this is in sweeden - are there any stockists in england? Also elfa stock smr 2.2uf, 100V but this is not the 63V variant recommended on acoustica - would 100V be ok instead of 63V ?

I would be very grateful for any help given as this is my first foray into the art of bodging and cant wait to get started.

Thanks stu

 

[Mus]

Stu,

100V MMKs should be fine as long as they are not physically too large. However, there are some very cheap 63V MMKs on eBay: MMK-Series-2.2uf-63V. You should be able to sell any extras here in batches of 10/20 no problem, I'd buy 20 from you to get the ball rolling.

You can buy the Elna Slimics from RichardH right here on PFM by dropping him a PM; if he has none left I can sort you out.

Regards,

Mus

 

[zener]

I've got loads of 47uf silmics , how many do you need. I also have 2 BC128 10uf 25v caps if you want them all FOC

 

[mega lord]

Mus and zener,

Thanks for your replies.On acoustica site it says to replace the blue 10uf, 35v tants on the input coupling of all boards in nac72 with evox smr 2.2uf/63v polyphynlsulphide. Will the evox mmk 2.2uf/63v on ebay be suitable in this position instead of smr series bearing in mind mmk's are polyester not polyphynlsulphide? Are there any other positions i could use them in nac72 or nap140 or cd3.5 or hicap?

Zener - a very kind offer which i will take you up on if i may. I think 10 elna silmic 47uf/35v would be enough to keep me happy. Bc128 - yes please. Can i PM you ?

thanks stu

 

[hacker]

Stu,

I've got a couple of Evox Rifa 47uF MMK caps - I can't give 'em away, but they won't cost you much. I've also got some 2u2 SMRs - I'll have to check how many. I didn't like using 2u2, as I felt some of the bottom-end grunt was lost... the deep bass just wasn't there and I went back to using 10uF SMRs.

Just drop me a PM if you're interested.
Carl

 

[stevew_w]

IMHO the BC128 make the best in/out decoupling for the 321 & 729 boards in the NAC 72. Using the Evox MMK 47uF in the feedback loop of the 321 boards is slightly better than the silmics, however they are physically big and have to be mounted off board, which is a bit of a pain. I used the OSCON SP for the power rail decoupling. I also removed the unused tape loop buffer boards. I have also bypassed all the above caps with 0.01uF WIMA polyprop caps.

You should also look at doing the Jim current source mod to the 321 as well.

I also fitted the Evox MMK in the feedback loop of my NAP250 and removed the input decoupling cap with very good results. Not sure if this is applicable to your 140 though.

If you have not done so already get a good solder sucker. I find this is the best way to remove old components and clean up the boards.

There is something very rewarding when your tweeks work.

Hope this helps

 

[zener]

PM me your address and I'll post them to you. I think I have 35 and 50v , 47uf silmics , I'll send what I have ... Jon