Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on February 13, 2018, 02:29:55 am

Title: Wrong e-caps or not ??
Post by: kagliostro on February 13, 2018, 02:29:55 am

I got few 22uF 35V and some 100V e-caps to be used at cathode as bypass capacitors

wrongly I got it unpolarized instead of polarized and I'm wondering if I can use it or if there will be issues

I know I can use polyester or similar capacitors as bypass capacitor

(also with better performance than the polarized e-caps because of theyr reliability over time)

but don't know about non polarized e-caps as bypass, will this be an issue if used for that purpose ?

Thanks

Franco

Title: Re: Wrong e-caps or not ??
Post by: sluckey on February 13, 2018, 03:53:33 am

Quote

but don't know about non polarized e-caps as bypass, will this be an issue if used for that purpose ?

That's fine. Marshall is fond of using a non-polarized 0.68µF cap as a cathode bypass.

Title: Re: Wrong e-caps or not ??
Post by: kagliostro on February 13, 2018, 07:26:10 am

Thanks Steve

Quote

Marshall is fond of using a non-polarized 0.68µF cap as a cathode bypass

I never had one of those amp under hand and watching to schematics I was thinking that the .68 cap was a polyester or other similar kind of item

not a not polarized e-cap

Franco

Title: Re: Wrong e-caps or not ??
Post by: sluckey on February 13, 2018, 09:12:40 am

Quote from: kagliostro on February 13, 2018, 07:26:10 am

I was thinking that the .68 cap was a polyester or other similar kind of item not a not polarized e-cap

That's right. It's not important if the cap is non-polarized. Still works the same. The only advantage of E-caps is their small physical size.

Title: Re: Wrong e-caps or not ??
Post by: PRR on February 13, 2018, 11:51:54 am

Non-polar e-cap costs more. Since we are cheap, we "never" use them when we have a steady DC and do not need non-polar.

Of course a cap in the hand is cheaper than ordering another cap. Use it.

You can pull on a rope but you can't push on a rope. A pipe or stick can take either pull or push. If the load is all pull, the rope is probably cheaper. But if you don't have a rope, and do have a pipe, use the pipe.

Title: Re: Wrong e-caps or not ??
Post by: kagliostro on February 13, 2018, 12:08:53 pm

Thanks Steve and PRR

I do not know if the salesman by mistake made me pay more or less the same price of the polarized capacitors

or if he actually applied the price of the list, the fact is that as price has not been exaggeratedly high

9 capacitors 22uF (5 - 35v, 1 - 50v and 3 - 100v) plus 1 mt of professional cable for balanced microphones

I spent € 15, not very cheap but also not too much expensive (around 1.40-1.50 € each capacitor)

Franco