Need help with capacitors value

[Sandm0n]

Hi,

I have 2 capacitors which I’m trying to find their values, any help will be appreciated.
Thanks

 

[Vovk Z]

0.68 uF, 250VDC and 0.1 uF (I don't know voltage rating, but I think it's about the same).

 

[Sandm0n]

Thank you

 

[ferret]

Which piece of equipment is this, if I may ask?

 

[Sandm0n]

It’s kind of a tube buffer.
I’m trying to understand it’s pcb as the bass is very weak.

 

[Sandm0n]

The 0.68uf is on the input and the 0.1uf on the output.

 

[ferret]

Make and model maybe? Overall picture of PCB/s?

 

[Sandm0n]

It’s a cheaply made tube buffer which is part of a finished product from an unknown brand name.
Please see the attached drawing.

 

[ferret]

Hi Sandm0n,
I have a 5670 based RIAA headamp and the output caps are also 0.1uF rated at 630V. The B+ I presume is in the order of 250V, so as Vovk Z said also most likely 250V rated. Can't hurt to get 400V rated caps to replace both the input and output caps. Unsolder one leg and test them. If the B+ is close to their ratings they can take a knock. I generally use caps that are at least 50% higher rated than the anticipated voltage. Best of luck

 

[Sandm0n]

Hi Ferret,


Thank you.
The B+ is 145 VDC, the heaters voltage is a bit high for a 5670 tube with 7.4VDC.

I opened a new thread on "TUBES" forum as I'm experiencing few issues with the tube buffer connected to any source.


Thanks again.

 

[Mark Tillotson]

Hi,

I have 2 capacitors which I’m trying to find their values, any help will be appreciated.
Thanks

Same coding as resistors, first two digits are verbatim, the third is the multiplier, assumed units are pF.


So 684 = 68 x 10^4 pF = 680000pF = 680nF = 0.68µF


104 is 100nF by same process.

 

[Sandm0n]

Thanks

 

[nigelwright7557]

680nf 250VDC

 

[Vovk Z]

It is easy with 680nF, but the question is voltage rating of 0.1 uF. TS can use 630VDC rated cap because of low enough capacity to be sure.
And of cause those letters (after 104) mean something and usually one of that letters mean real voltage rating. I just lasy to search. TS may need to look for some typical cap datasheet with voltage rating codes.
Usually manufacturers code precision (it is 5, 10 or 20 % for that cap) and voltage rating and usually those codes about the same in different manufacturers.