In most tube amplifiers, a significant fraction of the gain factor is supplied by the input stage. You could describe the input stage of a typical push-pull tube amplifier as consisting of two sections, the amplification stage, which adds voltage gain to the signal right at the input, and the "driver" stage, which is there to split the phase of the signal and also to convert voltage to current so as to drive the grids of the output tubes. Then the transformers once again convert voltage to current to drive the speakers. Many people use the term "driver stage" to include everything that comes before the output tubes. But I agree with someone else who mentioned that your input stage tube or tubes, the section that provides the initial gain of the amplifier, may be on the wane. On the other hand, the output tubes may just need break-in, whatever that is.
New power tubes lacking low end and slam
Quick question: I installed new KT120 power tubes (same as the prior original tubes) in my Cronus Magnum II for the heck of it. Previous tubes are roughly 3-4 years old. I had not been having any problems with the original tubes but figured fresh new tubes couldn’t hurt. After installing and biasing the new tubes they sound weak to me. Not as much low end and not as punchy. Is this normal? Will the low end improve after burning in? Or should I throw the older tubes back in?
Thanks and happy 4th!
Paul
Thanks and happy 4th!
Paul