by erichayes » Wed Jun 23, 2004 10:47 pm
Hi All,
Far be it from me to throw cold water on experimentation, but the 83 has at least two things going against it in audio work:
1. It has a directly heated cathode. This creates a zero-cross twilight zone similar to a silicon rectifier where the tube conducts less when the filament voltage approaches zero. This isn't a problem with indirectly heated rectifiers due to the thermal inertia of the cathode.
2. It's noisy. All ionic tubes, whether hot or cold cathode, generate hash that has to be dealt with. That's why you don't see VR tubes in supplies upstream of output tubes (you will see them as screen regulators on outputs that aren't being run UL), and why 0Z4s are found only in car radios. Lots of filtering/shielding might be needed to get an acceptable noise floor.
The 82 and 83 were developed to provide constant output voltage over a wide range of load currents. That's why they were almost universally used in tube testers even after silicon diodes were available. They have a forward voltage drop of fifteen volts, whether you're pulling 1.5mA or 150mA out of them. But that's all they were really good for.
The 83-V was a drop-in indirectly heated cathode substitute for the 83, within its limitations (it could only handle 175mA, as opposed to 225 for the 83), and the forward voltage drop wasn't as zener-like as the 83, but it was a lot better than the 80 and 5Z3 directly heated rectifiers of the time. The 83-V begat the 5V4, which begat our ol' buddy, the 5AR4/GZ34. This, to me, is the paradigm of high current vacuum tube rectifiers; it just has a problem of blowing up in rather spectacular fashion.
All that having been said, Shannon, the 83 is happy with the standard center-tapped , choke or cap input configuration. Just keep the tube vertical.
Eric in the Jefferson State