Replacing electroytics in signal path with non-polarised - which type of caps to use?

[jpcoetzee]

I recapping a 1970s Tandberg receiver and want to change the old electrolytics in the signal path to non-polarised type. But which type to choose? Film? Metallised film? Ceramic? Polyphenylene? Polythene? Polyester? Metallised Polyester? Polypropylene? Metallised Polypropylene? Non-polarised electrolytic?

I suspect that some of these are actually the same type of cap with different names.

I have searched here, but can't find a definitive answer. Some answers refer to replacing the electrolytics with newer or higher-quality electrolytics but these days you should be able to remove them altogether.

The values are 1u, 2.2u, 4.7u, 47u, 10u. Some are on the inputs, some in the pre-amp and some in the power amp. I don't believe in expensive esoteric (Black Gate) types - I'm simply upgrading with the modern, non-polarised equivalent.

Many thanks

[richie00boy]

You will struggle going above 2.2uF to find anything that is not physically a lot bigger than the electrolytic. To be honest any of them apart from the (non-polarised electrolytic) will be an improvement on the stability and lifetime of electrolytic.

[jackinnj]

Film caps get to be pretty large in these ranges -- WIMA has a new series, the MK2-SL in 16V and 50V which are extremely compact for 10u. These are polyester, not polypropylene.

You might just as well parallel the electrolytics with a high quality film cap --

[Conrad Hoffman]

IMO, new Panasonic and other caps are way better than what was originally in there, and way better than old caps, no matter how good they were when new. You'll probably be quite happy with new electrolytics, and there are a million posts about the wisdom of paralleling them with films. IMO, it won't hurt anything because there is almost always series resistance in coupling circuits, and it might help. Also, trying to shoehorn big films in places they weren't designed to go can cause noise pickup and stability problems. Not a good thing.

[jpcoetzee]

Originally posted by jackinnj
WIMA has a new series, the MK2-SL in 16V and 50V which are extremely compact for 10u.

Those look like the mutt's nuts. Any idea where I can get some in the UK?

[jackinnj]

Originally posted by jpcoetzee


Those look like the mutt's nuts. Any idea where I can get some in the UK?

My mutt is a b*tch so I can't opine on the relative sizes of their respective reproductive organs.

That being said, however, I first saw these on a development board from Linear Tech and got a few hundred of the 16V version. PM me if you need some. Mouser is going to have them, (which means that Future will as well) but they are on 12-week backlog.

[jpcoetzee]

Originally posted by jackinnj
PM me if you need some

Thanks for that offer. I will count them up and let you know what I need.

I've just had a look and I will have to drill out the circuit board to fit 5mm-spaced leads in. It's not too bad, definitely achievable. That would take the DC-blocking electrolytics out of the signal path in the phono stages, which would be well worth doing.

For the 4.7uFs in the line-in stages and 2.2uF elsewhere I can use WIMA MKS2 (5mm lead spacing) and drill out where necessary.

For the 1uFs I can use WIMA MKS02 (2.5mm lead spacing), no drilling necessary!

For all larger values I will use new electrolytics, Panasonic FC or similar. They're not in the signal path.

[jpcoetzee]

I finally finished this job! There's a description on AudioKarma here:

http://www.audiokarma.org/forums/sho...d.php?t=164399

[AndrewT]

small and cheap is polyester, (=MKT), (=Mylar), (=PES).

What is terephthalate shortened to? PET? anything else?

Polypropylene are generally much bigger and significantly more expensive.

I think both are available for motor start and motor run duty. But avoid all the electrolytic versions.

[peranders]

Originally posted by jpcoetzee
I recapping a 1970s Tandberg receiver and want to change the old electrolytics in the signal path to non-polarised type. But which type to choose? Film? Metallised film? Ceramic? Polyphenylene? Polythene? Polyester? Metallised Polyester? Polypropylene? Metallised Polypropylene? Non-polarised electrolytic?

I suspect that some of these are actually the same type of cap with different names.

I have searched here, but can't find a definitive answer. Some answers refer to replacing the electrolytics with newer or higher-quality electrolytics but these days you should be able to remove them altogether.

The values are 1u, 2.2u, 4.7u, 47u, 10u. Some are on the inputs, some in the pre-amp and some in the power amp. I don't believe in expensive esoteric (Black Gate) types - I'm simply upgrading with the modern, non-polarised equivalent.

Many thanks

I would only changed the caps to new ones with similar characteristiscs. The unit is old, remember that and you can't make high-end of it.

1 uF could be changed to 1 uF/63 V polyester and 2.2 to 2 x 1 uF polyester. The rest, take fresh electroytics.