Polypropalyne Cathode bias caps

[acorn]

Hi all

Has any one got any thoughts as to the benefits of replacing those cathode bias electrolictics in the output stages for solid polyproplyne types of a similiar value.

I would assume that this change would result in a much improved sound quality, ie has any one tried this and compared both types of caps.

Regards Acorn

[lt_texan]

I've got the output stage of my 2A3 hooked up ultrapath with solens ployprops. No complaints here.

Dan

[andrew ivimey]

say goodbye to electrolytics, if you can, and welcome the good news. I use solens wherever I can for cathode bypass.

[buddam]

So Andrew, if say C14 and 15 in Phono II are 10uf/450V polarised 'lytics, they could be swapped for polyprops space permitting?

Off topic (sorry) I haven't forgotten the 2a3, but snowed under just now.

Adrian

[david counter]

I've got M caps as the cathode bypass in my 2A3, they are a real improvement over the previous electrolytics, IMHO worth doing if you've got the space

[prince of darkness]

Originally Posted by lt_texan

I've got the output stage of my 2A3 hooked up ultralinear with solens ployprops. No complaints here.

Dan

How do you connect 2A3's ultralinear? I thought this was pentode/beam tetrode only.

[lt_texan]

Originally Posted by prince of darkness

How do you connect 2A3's ultralinear? I thought this was pentode/beam tetrode only.

only I know how to do this! (see edit above)

[acorn]

Hi all

I believe that Polyester are on par with Polypropylne ones, as any one compared them, as the Polyesters can be made smaller.

I am soley tempted to have some customed made flat ones at 50 VDW to my spec so they would be small enough to fit on my tag boards, the problem is a 22uF and a 44 uf is a big beast so getting the size right is going to be difficult, any thoughts on this point folks, or is it a case of roll your own.

Regards Acorn

[Clive]

I don't think Polyester are as good as polyprop but a use a polyester of the value you need and bypass this with a polyprop or two, maybe 0.47uF and 0.01uF?

I've not done this myself but I've done this on a coupling cap, 2u2 polyester with a polyprop 0.1uF and 10nF silver mica.

[andrew ivimey]

space permitting, Adrian YES. polyprops are much better than poly anythings. If you can go for silver mica, even better. Teflons too are huge but excellent.

electrolytics, unless BGs are not so good; just small.

(The LW output trafos are being used for something else, now Adrian. The recommendation however stays the same. p.s. There is a Hammond mains trafo which does all the voltages inc the 2A3 heaters in one. Philip at Bluebell does it for £65 plus VAT but I think worth every penny)