The problem lies not with the 12AT7 tubes it lies with the Atma-sphere and its gain. When you have old stock 12AT7s that will work with 99 out of 100 preamps with the single odd guy being the Atma-sphere...guess what is to blame? I have nothing but the highest respect for Ralph and Atma-sphere but I think that blaming old stock tubes is nonsense and noise at least with the older MP-1s was a real problem.
Now it makes sense that when Ralph designed this piece he would use new production tubes not old stock and I think this is likely the case.
Now it makes sense that when Ralph designed this piece he would use new production tubes not old stock and I think this is likely the case.