bias can be the main problem. what tubes your amp is using?
i can tell you what tube pin you should check for grid voltage in order to have a correct bias before you place the new tubes there. also i can direct or perform an installation of the bias measurement circuit almost on any tube amp with potentiometers for a neccessary adjustement when needed.
i can tell you what tube pin you should check for grid voltage in order to have a correct bias before you place the new tubes there. also i can direct or perform an installation of the bias measurement circuit almost on any tube amp with potentiometers for a neccessary adjustement when needed.