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AVX film cap group buy?

Martin,

I found some 680 FKP2 Wimas and stuck em in. I do believe there is an improvement, well I smiled anyway. I hope I like it tomorrow.

Thanks.
 
martin clark said:
Someone has already mentioned it - but do try caps like this both ways round. I had exactly the same experience with some large MMKs used for signal coupling...

To get this much capcitance in a fim cap this small means a lot of (thin) film area wrapped-up very tight, and there will be quite a lot of stray C from one end to the rest of the world. In a sensitive position like feedback coupling, depending very much on layout, this could make all the difference. I've sometimes found that (strangely) loss of apparent bass is sometimes related to amplifier unhappiness way above the audio band...

Since none of these caps will fit straight back into most amp boards another thing to try would be to add a very small, high quality film cap in parallel, but right on the board where the original tant went. Something like 470pF - 1nF or so, film/foil (eg Maplins stock 'em, they're wima FKP1/2s) will keep all the HF local to the board and tend to swamp unwanted effects from extended wiring loops, cap orientation etc :)
Click to expand...

So I flipped the AVX caps and added 1nf in parallel and the result is a big improvement. The low bass is back and the overall sound is a worthwhile improvement on the 22uF Wimas. I know I should have done the two changes in turn, I'll pop out the 1nF when I get some time to see what's really having the influence.

Thanks once again for the input.

Andy
 
Mine are a little better, but still not as happy as I was overall with the system. Which way round are they, can you describe it by the writing relative to the 0V connection?
 
Hi,

Mine are that way round and the low bass is lacking I feel but I am leaving them to run in before I do anything.

Pete
 
Yes "P1" to 0V here. Bass (125 to 200hz) seems light. Mine are well run in.

Martin, what would happen if I put a much larger value tant in instead? I assume it would increase the bass level, but given that this amp doesn't see deep bass would it function ok (mid range active > 125hz).

I have some 220uf and 150uf going about.
 
trancera said:
Yes "P1" to 0V here. Bass (125 to 200hz) seems light. Mine are well run in.
Click to expand...


One can only assume that all the caps are printed the same way round. It may be that the printing / stamping process is done after the layers are encapsulated.

These were never really intended for audio purposes so any directional characteristics would not be observed by AVX. Maybe the differences would be on a batch by batch basis rather that individual caps but it could still be worth swapping them round.
 
I don't think there is much in the direction, just a guess. Also running in, well these are massively over spec here so doubt they will change much. The small cap I added helped but I think these will be coming out, and very soon.

Have to find somewhere else nice for them ;)
 
I think they may well work very well for that, almost like no capacitor being there.

Mine are out of the NAP feedback and some large axial tants are in, lovely.
 
Well I am back to uncontrollable belly chuckles sitting in front of the hifi, amazing what it does. Phew! Its actually better than before because I removed the old original Naim tants for the AVX then went on to the Axial tants I had to hand which we have known are better. Removed SOA and also fixed the on/off switch sticking!

So, I am well pleased with the outcome, its worked out very well. I will look to use the AVX in a non FB position...
 
I am unsure Chiily. However I think they are dry tants, they don't look like wet ones I have seen with the dip in the out diameter.

All they appear to be doing is a little more of what the original Naim tant did, so for me are spot on. Other ears are available ;)
 
Its only doing the Mid Range so sour is ok ;)

I have discovered these caps are quite expensive :eek: and the ones I have are mainly AVX it seems.
 
Wow some versions of the AVX new wet tants are over £100 :eek:

But they are very bad for your health:rolleyes: send them to me and I will dispose of them safely for you:D

Alan
 
I've got some solid axial tants here - I can make them wet... not sure that's what they mean...
 
Meanwhile, my allotment from the GB has made it safely across the pond and beyond. Thanks, James, for your good effort!
 
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