Can’t use any other tube??!!?


I just got a used Rogue Cronus Magnum 2, and I want to roll a few tubes I have into the center 21au7 spot to see if I can beat the stock JJ.

Every tube I try is noisy - crackling and hissing. Even tubes that I take from another amp where they are crystal clear.

But when I put the JJ back in - it’s quiet again.

I have tried new production Mallard and two different NOS Mullards.

Any ideas why only the stock tube is working? 


stephenjess

Showing 1 response by atmasphere

Any ideas why only the stock tube is working?
In any high performance tube equipment the tubes are hand-picked. Your 'replacements' are not. They are just random tubes. You need a 12AU7 that is picked for low noise and low microphonics.