I bought a unison research cd player from pmac some time ago on the wam when it was popular.
The tj full music 12ax7 s that were in it sounded good but like all good things, came to an end. As these tubes aren’t available any more I opted to buy the best nos I could afford - 4x GE jan 12ax7wa.
I am thinking the player is now sounding rather bass-lite.
What I would like to know is - is vintage nos in a cd player a mistake and/or is this down to the character of these particular valves? And if anyone with the experience could recommend a good alternative to the tj full music?
It’s always a personal thing and specific to the circuit, so there’s never a single right answer. Fortunately it’s a common valve so there are plenty of interesting ones available. I’m not sure if NOS Mullard ECC83 are readily available, but there is a remake that’s quite cheap: http://www.thetubestore.com/Tubes/12AX7-ECC83-Tube-Types/Mullard-12AX7-ECC83