The difference that matched tubes made on early-production Atma-Sphere MA-1s was like night and day. Roger Modjeski of RAM Labs was extremely helpful in this regard.
OK to use unmatched or different brand tubes?
My preamp has 2x 12AX7 and 2x 12AU7.
I am thinking of trying different tubes.
Would it be OK to use a pair of tubes with the same brand without testing their current levels?
How about using a pair of tubes from different brands with matching current levels?
How about using a pair of tubes from diffenret brands without testing their current levels?
Overall, if a new pair pair of tubes make improved sound, the mathing of current or brand does not matter?
I am thinking of trying different tubes.
Would it be OK to use a pair of tubes with the same brand without testing their current levels?
How about using a pair of tubes from different brands with matching current levels?
How about using a pair of tubes from diffenret brands without testing their current levels?
Overall, if a new pair pair of tubes make improved sound, the mathing of current or brand does not matter?