So what is a ‘Phase Splitter’. Something to do with Flash Gordon, I bet.

And if you remember Flash Gordon, you must qualify for ‘Old Git’ status. Surely.

Let’s clarify this. There’s a first time for everything.

The ‘Flash Gordon’ I’m on about is not the one that Freddy Mercury waxed lyrical about. No. The Flash that I’m referring to was the one where the smoke from the rockets in outer space went upwards…..? I’m ashamed to admit that that is the only thing I can recall from my hundreds of Saturday morning visits to the local bug’s hut, the Coliseum.

Back on the topic. I think that might have been the shilling each way I bet on the dog with three legs called ‘Flash Gordon’. It lost.

A phase splitter in not a ‘phase inverter’. They are often called that these days (just as a thing you lose or break regularly is called a ‘phone’), but the phase inverter, is actually any valve that has its output from the anode. Whereas the phase splitter actually splits the phase of the input and is a specific circuit arrangement that is designed to drive two halves of a push-pull output stage. One side anode goes positive and the other side anode goes negative. Hence the phase splitting thing.

The point of this (there’s a POINT?), is that, although a lot of emphasis (and money) is put on output valve matching (and rightfully so), the phase splitter which feeds the grids of these output valves are rarely spoken about. But an internally matched ECC83 is basically a double triode valve, and if the outputs of those anodes are not well matched, the big bucks you’ve spent on some really nicely matched output valves wasn’t worth the dog I bet on called Flash Gordon.

The output valves can only reproduce whatever is going in, and if that is not symetrical, neither is your output signal.

It’s always hard to describe a sound, but the effect of this imbalance, to me anyway, is a loss of clarity and weakness of the sound. So next time you need to change output valves, get a nicely matched phase splitter to go with them.




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