Ge Noob: 'splain me about Ge Clippers

[Rich_S]

I was just ordering some 1N34A diodes off eBay for a Cupcake I'm building.  While I was ordering , I grabbed some 1N270's as well, since I have Distortion+ on the brain.  The D+ schematic I have mentions subbing different diodes for different sounds, it says 1N270 was the original, and recommends 1N34A for a fuzzier sound.

That got me looking at spec sheets, but I don't see specs that would explaing the difference on the sheets.  Namely, both diodes are spec'd with Vf = 1.0.  The 1N34A refers to this as "Maximum Instantaneous Forward Voltage", the 1N270 just calls it "Forward Voltage Drop".

So, noob questions time: how do you know from the data sheets how the diodes are different in a guitar FX clipping application?  Or is it all just experience and folklore, and I just need to ask non-noobs about stuff like this?

Also, since I'm a bit suspect of eBay sellers of nearly obsolete diodes, is there a way I can test them to 1) confirm they are the right part, and 2) tell them one from the other?

[midwayfair]

1n34A and 1N270 will have different forward voltages. It's about .3v for 1N270 and .35V for 1N34A. This means that 1N34A will be louder, clip less, and likely have slightly less treble overall.

Spec sheets are really not terribly helpful with diodes as clippers, at least not in my experience.

The 1N270 is better for the Cupcake. I would argue that a Schottky diode is even better since it will match the 1N100 (Fv ~2.4v-2.6) more closely and is far cheaper. But as clippers go, it's very tough to beat 1N270.

I've got an old thread around here if you're really curious about lots of diodes.

[hammerheadmusicman]

sorry to `jack this thread', but something just clicked in my brain and i really wanna ask something! How you test for the Fv? Or is this info coming from datasheets etc..? Hopefully this is helpful to you as well, and not some much of a 'thread jacking'

thanks

George

[midwayfair]

sorry to `jack this thread', but something just clicked in my brain and i really wanna ask something! How you test for the Fv? Or is this info coming from datasheets etc..? Hopefully this is helpful to you as well, and not some much of a 'thread jacking'

thanks

George

Set your multimeter to continuity. Place the black probe on the cathode and the red probe on the anode. The measurement shown is the forward voltage drop across the diode.