Are all GZ34's born equal?

[Diabolical Artificer]

At £20 - £28 a pop I'd be tempted if possible to use silicon diodes. As Joe says some aren't much cop, bit of a minefield trying to find a good one but both Langrex & Billington have them, whether Chinese or Soviet who knows but they're the only ones making valves nowadays. It's either that or a NOS Mullard for £100 up! That said a 5R4WGB CV4026 might be cheaper and easier to find as NOS. A lot of folk don't like them as they look "wrong"

Andy.