06-29-2014, 01:48 PM
This is a pretty common question with the v4/vt22. can't say I blame you since they are so darn loud. But there are two things to keep in mind. First, the amp doesn't get much quieter. Many people confuse half power and half volume. With only two tubes the vt22 will still be really loud, volume reduced 10% or less.
Second thing is that the half power switch on so many amps just disconnects the cathode on two of the power tubes. This doesn't make sense because that changes the output impedance of the amp. The speaker load is then fully carried by two tubes instead of four. It's like running an 8 ohm out into a 16ohm cab.
You can pull two tubes run switch the impedance to 4 ohms and run a 8 ohm load, or switch to 2 ohms and run a 4 ohm load. That would keep the ratios correct and not overwork your tubes. But again, for what gain? As I mentioned above the amp doesn't get much quieter.
I don't mind pulling tubes and changing the output impedance to correctly match the amp to the speakers. It's also super easy and doesn't require a switch rewire.
Second thing is that the half power switch on so many amps just disconnects the cathode on two of the power tubes. This doesn't make sense because that changes the output impedance of the amp. The speaker load is then fully carried by two tubes instead of four. It's like running an 8 ohm out into a 16ohm cab.
You can pull two tubes run switch the impedance to 4 ohms and run a 8 ohm load, or switch to 2 ohms and run a 4 ohm load. That would keep the ratios correct and not overwork your tubes. But again, for what gain? As I mentioned above the amp doesn't get much quieter.
I don't mind pulling tubes and changing the output impedance to correctly match the amp to the speakers. It's also super easy and doesn't require a switch rewire.