On Wed, 10 Oct 2018 15:02:53 -0400, Ralph Mowery wrote:

When restoring the old tube equipment (tube receivers ) does it make any
difference if the old paper capacitors are replaced with the ceramic
disk or should another type be used ?

I know for RF one needs to use capacitors that are rated for rf but in
the audio stages does it really matter what kind of capacitor is used as
long as it is the correct value ?


Reason for asking is that I bought an old receiver that someone has
replaced many of the capacitors. The book says pape capacitors for some
but they have been replaced by the ceramic disk type.

So, I dug out my old Hallicrafters S-38 and did a side by side comparison with the National NC-60. The S-38 has only film caps in the audio path and does sound better than the NC-60.

I'm done with working on the NC-60. It's working pretty well and I'm not going to take the time to chase down nit-picky problems like that. So, I don't really know what's causing the audio imperfections. Could be the caps, could be a dozen other things.

This might be informative but I know it's certainly not conclusive.