Grid Stopper Advice - Graphs Included!

[Magz]

And here is a 20kHz sine wave, followed by a 2kHz square wave (with no resistor loading of the transformer).

I'm thinking that since the 1.5kohm loading is ringing-free, that should be my choice - agreed?

 

[Magz]

Well, just to bring this thread to a close, I found a better way - thanks to a lot of reading, your help and some experimenting...

I'm now using a snubber network across the transformer secondaries. What I found to be optimal is 2nF and 520ohm. This gives me a good square wave at 20kHz, and best of all, doesn't take away gain like the resistor-only network does, so it is the best of both worlds.

Thanks to all who helped me!

 

[fdegrove]

Hi,

Good, the xformer was ringing so the snubber killed the self-resonance.

Some may remember an article way back in Glass Audio where the use of gridstoppers on a preamp designed by the author miraculously brought back detail and god knows what else.

Always ready to try something out I found that in my own premaps it didn't do anything but veil the sound with the sonic fingerprint of the added resistors.
No added detail quite the contrary.

Any takes on this?

Cheers,

 

[Magz]

Here are 20kHz scope traces, before and after snubbing.