How do I know if my phase inverter tube is bad?
Loss of Power and other Odd Noises Sometimes you will hear strange sounds, loss of power, or heavily distort sound. These are signs that a tube is failing. Often power loss that seems like the amp is performing at half power or less will be one or more bad power tubes, or even a dying phase inverter tube.
What does the phase inverter tube do?
The phase inverter is the last stage in the amp before the output tubes, and in all amps other than single-ended types with just one output tube (Fender Champ and Vox AC4, for example), this stage splits the signal into two reverse-phase strands to send on to those big bottles for final amplification.
How important is the phase inverter tube?
There are no amp adjustments necessary when you change the phase inverter. It makes sense that the phase inverter is very important. It’s feeding the signal from the pre-amp into the power-tubes and has to make that signal change very cleanly, without adding any distortion.
How long do 12AX7 tubes last?
Small signal tubes like a 12AX7 or 6922 will work well on average for about 10,000 hours.
Can 12AX7 be used in phase inverter?
“Going from a 12AX7 to a 12AT7 in the PI (phase inverter) will yield a change in output tube distortion, touch, and output dynamics in most amps. …
Can I use 12AX7 instead of 12AU7?
Technically, yes, you can physically interchange a 12AX7 tube for a 12AU7 tube in your amp without risk of major damage to your amp.
Do driver tubes affect sound?
The rectifier tube is not the direct cause of the quality of the sound in the power supply. The whole design of the power supply is what affects the sound quality. i personally would say as long as the rectifier tube is working properly, that is all it can do.
How can you tell if your inverter tube is bad?
Sometimes you will hear strange sounds, loss of power, or heavily distort sound. These are signs that a tube is failing. Often power loss that seems like the amp is performing at half power or less will be one or more bad power tubes, or even a dying phase inverter tube.
When does a phase inverter distort the output tubes?
When the output tube grids approach 0v and are driven positive, they no longer look like an infinite input impedance and begin drawing grid current. Because the phase inverter was not designed to deliver this grid current, the phase inverter sees a much heavier load when the output tubes distort.
What does the driver do in a phase inverter?
What you put in is what you get out, except one side is flipped-phase. Therefore, an additional tube stage called a “Driver” is used ahead of it. The Driver provides the gain, the Cathodyne inverter provides the necessary phase-flip, and they both live as a happy family.
How does a split load phase inverter work?
The Split-Load is the simplest arrangement. It splits the signal by virtue of the fact that the signal appearing at the cathode of the tube is in-phase (this circuit by itself is called a “Cathode Follower”), while the signal at the plate is out-of-phase (this is a typical Common-Cathode amplifier).