If you haven't already answered your question...... the 5AR4 will work just fine.
I have a dared sl-2000a preamp., it comes with the stock 5z4p.
It blows fuse immediately, and seems to spark inside rectifier tube.
i don't have another 5z4p.
i have other tubes around (5u4GB, 5AR4, etc)
is it ok to put the 5AR4 and a new fuse in and try? I don't know if it's simply a. As rectifier tube or other problem.
any advice appreciated.