The RAM Tube Store meticulously measures all tube parameters, including noise. They then grade each tube, and offer matched pairs and quartets. They offer a Super Low Noise 12AX7's for use in phono amps, etc. A very quiet 12AX7 substitute is the 5751, which provides slightly lower output.
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...
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...