WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
I saw one 300B SE design using GZ37 as rectifier. However, this tube is hard to find in anywere! If I were to use the equivalent one, what shoud this tube be?
Be careful. The reason why GZ37 is sometimes specified is because although the obvious choice is GZ34, some recent production has been reported to have had problems with arcing at higher voltages, whereas the NOS GZ37 is known to be of good quality.
Pretty much. However, if you're building from scratch, there's a better alternative, and it's cheaper, too. Use a pair of 6CL3 or 12CL3 instead. A pair of these are actually beefier than a GZ34. They're certainly cheaper.
