Expanding questions about tubes in a preamp


Hello to all...

Started with a (helpful) discussion titled "How to select tubes for a line level preamp"... Expanding questions that have generated from that...

Have learned that hum/noise from tubes is a major consideration - now trying to figure cheap ways to address quieting the 12AX7s and the EF86s.

Would like to try "banding" the tubes with rubber ring washers - one?two?three per tube?

Where should the rings be on the tube: Top? Mid? Bot?

Can you over dampen a tube?

Knowledgeable tube users/ Masters input/suggestions please...

insearchofprat

Showing 1 response by br3098

Gents, how the hell does adding damping rings change the sound of a tube. Nonsense! If your tubes are microphonic (ringing) adding dampers may quiet them down. If you have a noisy tube it won't help. But it also won't hurt. I have never heard anyone complain about, nor have I noticed, a change in sound due to the use of tube damping rings.

Using rubber bands as tube dampers? Sure, go ahead. As long as you don't mind smelling cooking rubber and the bands sticking to your expensive tubes, then cracking and falling off. Rubber bands are not designed to be heat treated.

Next silly suggestion: why not just coat your tubes with a healthy dollop of undercoating? It made my '67 Bug quieter.