Anothr part question: Ge diode substitution

[Ben N]

I'm putting together a Mouser order, including for an Octave Screamer, and 1N270 is apparently obsolete. They recommend as a general replacement a Schottly, CDSH270. Another Ge also comes up on the search, NTE109. Since I haven't come up with a 1N270 datasheet, I can't compare, and even if I could, I don't know what the critical characteristic(s) is/are for this application. Are either/both of these suitable? How about 1N34A, of which I think I still have some at home?

BTW, does anyone know if Steve has 1N270s? Small Bear is blocked at work, but Mouser isn't.

TIA,
Ben

[phil]

BTW, does anyone know if Steve has 1N270s? Small Bear is blocked at work, but Mouser isn't.

Just checked and he's got them for .75 each

[petemoore]

How about 1N34A
  I've had glass and blue and various Ge's, as long as they're Ge diodes...then you can measure the Vt on if for some reason particular, I couldn't tell a difference one to the other in TS.
 

[mars_bringer_of_war]

This brings up a question:
I've always understood (always=5 years I've been diying pedals) that as far as clipping diodes go, you could interchange any si and/or any ge, the only difference with different pairs/types being the amount of signal clip. Is this so?

[Ben N]

Let me point out that my original inquiry was about use in a half-wave rectifier/octave, which may have a different answer than the standard clippping pair aplication, I don't kow.

Also, that upon re-review of Scott's schematic, I noticed that he says 1N34A is fine. 

[MartyMart]

Let me point out that my original inquiry was about use in a half-wave rectifier/octave, which may have a different answer than the standard clippping pair aplication, I don't kow.

Also, that upon re-review of Scott's schematic, I noticed that he says 1N34A is fine. 

For octave use , just remember to "match" the pair of diodes, so you want the same forward voltage drop
EG - better octave effect if both were say 0.42 v  or as close as poss from a batch.
MM

[petemoore]

Let me point out that my original inquiry was about use in a half-wave rectifier/octave, which may have a different answer than the standard clippping pair aplication, I don't kow.
  Yes it's different, with octave you might want the wave folded evenly, comparator the + and - signal swings, a little or more perfect matching here will make a difference in the type and amount of harmonics including octave you hear or are cancelling each other out or interacting in other ways.
   For octave use , just remember to "match" the pair of diodes, 
  I'm not with scope, but the symmetry/assymetry of the incoming signal to the diodes also controls how symmetrically the diodes conduct on the -/+ 'halves of the signal swing.
  If the _ and + voltage swings that the diodes will see are symmetric, having matched diodes [symmetric] should produce the most pronounced octave, YMMV.
  I matched also the symmetric resistors in the phase splitter, and tried to match all parts in the FWR that looked to have to do with symmetry there...but then used the Green Ringer mod which allows adjustment of one of those resistors, so the FWR can be adjusted to symmetric or bigger swing on either side +/- of the signal input.

[MKB]

An easy way to get a Ge diode is to use a Ge transistor, for a PNP transistor the emitter is the "anode" and the base is the "cathode".  If you have ever bought a batch of untested Ge transistors, you probably have a bunch of leaky ones lying around that don't work well in a Fuzz Face or Rangemaster.  The leaky ones are perfect to use as diodes.  IIRC, Robert Keeley came up with this idea.

[markm]

An easy way to get a Ge diode is to use a Ge transistor, for a PNP transistor the emitter is the "anode" and the base is the "cathode".  If you have ever bought a batch of untested Ge transistors, you probably have a bunch of leaky ones lying around that don't work well in a Fuzz Face or Rangemaster.  The leaky ones are perfect to use as diodes.  IIRC, Robert Keeley came up with this idea.

I thought it was an R.G. discovery but, I'm not sure. 
On a different subject, I thought Keeley invented the Compressor?? 

[Ben N]

On a different subject, I thought Keeley invented the Compressor?? 

Not Al Gore? 

[markm]

On a different subject, I thought Keeley invented the Compressor?? 

Not Al Gore? 

No, no,
He invented Global Warming.......or caused it perhaps.