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

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jpcoetzee

jpcoetzee

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Joined 2008
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
 
C

Conrad Hoffman

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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.
 
jackinnj

jackinnj

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Joined 2002
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jpcoetzee said:


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

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

jpcoetzee

Member
Joined 2008
jackinnj said:
PM me if you need some
Click to expand...

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.
 
A

AndrewT

R.I.P.
Joined 2004
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

peranders

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

jpcoetzee said:
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
Click to expand...
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.
 
jpcoetzee

jpcoetzee

Member
Joined 2008
AndrewT said:
so tell us what you did and how it's great.
Click to expand...

Have a look at the thread on AudioKarma for "what I did".

It sounds great because the sounds is clear, with bass accurately reproduced even at volume. Vocals are well-defined. The phono input also reproduces vinyl with clarity and lack of distortion or pickup. The FM tuner pulls stations in well and even in stereo mode the hiss is almost inaudible (I don't have a dedicated FM aerial).

I'm not very good with words like "transparency", "soundstage", "open", "pace" etc etc.

HTH!
 
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