Re: 1n34a diodes

Posted by induction on May 26, 2016; 3:55pm
URL: http://guitar-fx-layouts.238.s1.nabble.com/1n34a-diodes-tp30980p31005.html

Remember, a component is defined by a datasheet. If its measured specs match the tolerances of the datasheet, it's 'real'. If it doesn't, it's not. Lots of semiconductors can't be manufactured to precise specs, so they make a ton of them, then label them according to how they measure. It's generally not possible to tell these specs by looking at them, and there's no reason to expect different manufacturers to use the same cosmetics (band colors, etc.)

If you want to know whether a diode is Ge or Si, there's no sure-fire way to tell from looking at a picture, but if it's a small package (1N4148 size) it's probably Si. If it's a larger glass diode with a visible cat whisker, it's probably Ge. Whether it's a 1N34A depends on the measurements.

In most applications the difference between Ge and Si is only about the forward voltage, and the knee. (I'm pretty skeptical the latter, to be honest.) If you replaced a Ge diode with a Si diode that has exactly the same Vf, could you hear the difference? I never have, but maybe that's just me.