Shunt regulator for a phono pre

[ALW]

Frank

I could add to it by saying that using filmcap for PSU filtering is also not such a good idea although for other reasons.

Would you like to offer a reason why?

Andy.

 

[fdegrove]

Hi,

Would you like to offer a reason why?

Well, I can only try.

The lesser electrolytic caps tend to filter out mainsborne crud, rectifer noise and what have you far more effectively than a filmcap would in a typical CRC filter.

On the same topic, does anyone use capacitance multipliers for their circuits?

While these are limited in use due to max. transistor dissipation, I find them very useful, even in valve PSUs.

Moreover, they don't cost much to cobble up and try out.

Lately, I've been fiddling with one for a tube preamp, using a //ed ECC81 and I'm really smitten with the results.

Cheers,

 

[ALW]

The lesser electrolytic caps tend to filter out mainsborne crud, rectifer noise and what have you far more effectively than a filmcap would in a typical CRC filter.

Surely isn't the filtering effect totally dependant upon source R and the resultant cap Z?

I see no reason why a film cap should be worse than a 'lytic of the same value.

I'm puzzled...

Andy.

 

[fdegrove]

Hi,

I see no reason why a film cap should be worse than a 'lytic of the same value.

Where a filmcap is too good in this application is in DA.

If we'd use regular, off the shelf caps their " poor properties" can be put to good use to help suppress RFI.

I'm not saying they'll do everything you've ever dreamt of but they smooth these critters out better than a filmcap would in that position.

Neither am I saying that you can't use filmcaps in a PSU but if you're going to use regulators anyway, I see no point.

After all, all you need is a clean supply and good PSRR from the reg and whatever sits in front shouldn't leave its sonic fingerprint.

Any opinion on the cap multiplier?

Cheers,