As mentioned above, if your amp is self biasing or has individual bias pots, you don't have to get matched tubes, though it does not hurt as it may help to assure you that there is nothing whacky in the way the tube measures.
If the amp is cathode biased like the Rogue I prefer to use matched sets. If you have an amp with one bias adjustment for each pair or quad you really should use matched sets.
The issue here is how the tubes idle...it's like having four carbs on a car...they should be synchronized. If one tube is a current hog, it will run too hot in relation to the other tubes and fail early.
If you need matched sets, when buying a re-tube...ask the tube seller to give you the measurements to refer to if you lose a tube. That may help. Though most tube sellers matching rigs do not have regulated power supplies, so the batch they test six months later when you call may have a bit of a variance from what they tested for you.
That's why we had to get our test equipment custom-built. Our single tube tester is regulated.
Our new tester was built by Eric Barbour, the former Chief U.S. Engineer fro Svetlana Electron Devices.
The Hewlett Packard Power Supply we use cost more than entire test apparatus that are sold. Together between the two racks it will test/burn 40 tubes and weighs over 200 lbs.
I don't know why the commercially available test rigs don't have regulation. Even the Sophia curve tracer does not last time I read. It would raise the price, but makes for a really usefull tool.
If the amp is cathode biased like the Rogue I prefer to use matched sets. If you have an amp with one bias adjustment for each pair or quad you really should use matched sets.
The issue here is how the tubes idle...it's like having four carbs on a car...they should be synchronized. If one tube is a current hog, it will run too hot in relation to the other tubes and fail early.
If you need matched sets, when buying a re-tube...ask the tube seller to give you the measurements to refer to if you lose a tube. That may help. Though most tube sellers matching rigs do not have regulated power supplies, so the batch they test six months later when you call may have a bit of a variance from what they tested for you.
That's why we had to get our test equipment custom-built. Our single tube tester is regulated.
Our new tester was built by Eric Barbour, the former Chief U.S. Engineer fro Svetlana Electron Devices.
The Hewlett Packard Power Supply we use cost more than entire test apparatus that are sold. Together between the two racks it will test/burn 40 tubes and weighs over 200 lbs.
I don't know why the commercially available test rigs don't have regulation. Even the Sophia curve tracer does not last time I read. It would raise the price, but makes for a really usefull tool.