diytube.com

Has anyone every done a listening test to see if there is any sonic difference between using the .02uF stock ceramic caps or polypropylene caps between the centertaps of the filament windings and ground?

I wouldn't think it would make much difference, but I've been surprised before by things that I didn't think would make a difference.

Scott Novak

Since the caps are not in the signal path it doesn't make a difference which type of cap is used as long as the same voltage ratings are used. Dynaco used a dual ceramic cap with three leads for low cost.

mesherm wrote:Since the caps are not in the signal path it doesn't make a difference which type of cap is used as long as the same voltage ratings are used. Dynaco used a dual ceramic cap with three leads for low cost.

That's an assumption. There is stray capacitance linking everything in the signal path. The question is whether or not there is a sonic difference between the two types of capacitors in that location. The only way to know for sure is by a listening test.

Scott Novak

They bleed noise coupled through the heater-cathode junction to ground. Best to leave them, or even increase them.

Cheers!

Scott Novak wrote:

mesherm wrote:Since the caps are not in the signal path it doesn't make a difference which type of cap is used as long as the same voltage ratings are used. Dynaco used a dual ceramic cap with three leads for low cost.

That's an assumption. There is stray capacitance linking everything in the signal path. The only way to know for sure is by a listening test.

Scott Novak

I nominate Scott for the 1st Anal DIYTube Tin Foil Hat award.

20

Have replaced them with both same values and increased the values and tried different types. I go with a slight increase in value if possible. No, you do not hear any sonic differences.