Crossover components rolling ?

[Greg.]

Some further thoughts. My experience is that replacing electrolytic caps with the much larger polypropylene equivalents is a no brainier. This brings a massive improvement to sound albeit that the original electrolytic can also sound good. Simply, a polypropylene upgrade will make it much better. Thereafter, I would expect sound improvement to correspond with what you are prepared to pay for on your caps. I suspect a step from a Solen cap to a Mundorf oil silver/gold option will, sound wise be a relatively small step in comparison. It is for you to decide whether you think the extra cost is worth it.

[Chris]

Before I was using those large yellow Hovland caps, massive improvement with the Mundorf, on the bass you could use the Mundorf supremes. I did read a famous Italian brand use the supremes in a costly 6 figure set of speakers, they then poured some kind of black resin over the cross-over.

Any improvements will always be limited to the weakest link in a system.

Chris.

[Phil Y]

This got me curious so I got my calculator out of the drawer.
Using ohms law and an 8 ohm speaker, 200 watts comes out at 40 volts.
That will be DC I suppose so multiply by 1.4 gives 56 volts.
So, as long as I haven't got that completely wrong, 100v caps will be more than adequate for any normal domestic circumstances.
Those 63v caps should be fine depending on the power handling of the speaker, it is always nice to have a bit of a safety margin.

No harm in using higher obviously and you would probably need to as suitable caps are usually higher voltage anyway.

Phil.

[bob orbell]

Phil, DC to drive a speaker, are you sure. Bob

[Phil Y]

Well no Bob,
That is why I multiplied the voltage by 1.4.
I was thinking that RMS value is equivalent to DC so x 1.414 giving the peak voltage is what we need for AC music signal.

This was off the top of my head so I am happy to be proved wrong ☺

Phil.

[Chris]

I don't know why you would risk destroying £200 tweeter by using under rated capacitor, I would be very stressed at pushing the volume up, the voice coil is very delicate if the cap fails.

Chris.

[Greg.]

Good point, Chris. I agree. Millennium Tweeter is now £225 each. Why take the risk?

[Phil Y]

Hello chaps,

As a check, I looked up the Alcap reversible electrolytics on the Falcon site.
The standard ones are 50v and the "high power" ones are 100v so that sort of ties up.

Phil.

[Black Stuart]

Phil,
63V should be fine and remember the K series are mil. spec. so will have been tested beyond 63V.

To give you an idea of size, I happen to have a 2.2uF/63V on the desk it measures 32mm x 9mm. 22uF/63V are 50mm x 20mm.

I'm also going to use some Audyn rough foil 100uF x 100V, these are 34mm x 14mm. The 30uF/100V are 24mm x 9mm.

There are still some usable coupling values left 0.1uF/1uF 250/400V. All these K73-16 caps are silly prices. Don't expect any colouration, just transparency.

[Black Stuart]

Received an email today from someone I used to buy K73-16 caps from in Lithuania He's back in business - he has 6.8uF x 250V @ US 88 cents each, 24 x 48mm, that's a steal.