Best electrolytic capacitors

[TonyTecson]

psu caps are also in the signal path, they form zeros or virtual ac grounds....unavoidable, perhaps ac coupling caps is more doable...

poles and zeroes in case you are not aware are all over our amp circuits...

poles are responsible for lowering gains as frequency went up, while zeros are responsible for gains going down as frequency went down.....

we live with poles and zeroes in our everyday amps whether we like it or not...

[tiefbassuebertr]

Actually this is correct, because there are still sound differences on listening tests - even by compare different electrolytic versions in power supplies.
But according of the real values for "Power Supply Rejection" (PSR/SVR) reduced.

[Mark Tillotson]

Originally Posted by TonyTecson

poles are responsible for lowering gains as frequency went up, while zeros are responsible for gains going down as frequency went down.....

I wouldn't phrase it like this, firstly as this sort of thing really applies to first-order zeroes and poles. Also its perfectly possible to have a zero in a low-pass circuit and a pole in a high-pass circuit (RIAA filter springs to mind for a zero in a low-pass).


Perhaps a better description is that first order zeroes change the response slope in a concave way, poles in a convex way.



Once you move to second order poles there is Q to consider - a pole pair may be highly resonant making a narrow peak in the spectrum, a zero pair can be a deep notch.

[TonyTecson]

bypass caps in the psu rails of the super leach amps are first order zeroes...an rc network across ef86 plate load resistors in a Mullard 5-20 are first order poles...

this is what i was trying to say,

[duncan2]

Its a wonder D.Self hasn't chimed in as he had a lot to say precisely on the subject of poles.

[TonyTecson]

Steve Bench too....http://diyaudioprojects.com/mirror/m...sc/fb_faq1.txt