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Projects => Tech Help - Projects Page => Topic started by: micromegas on March 17, 2015, 11:32:18 PM

Title: Germanium diodes
Post by: micromegas on March 17, 2015, 11:32:18 PM
Ok, maybe this isn't really a "tech" question.

The thing is that I need a bunch of germanium diodes (some for my 2 apis boards, some for Rej's clone, some for a Kingslayer, some for a Kraken, etc....) and was thinking about going the D9E route as 1n34As are damn expensive right now.

I've seen an ebay seller I have had great trades with has a bunch of them at a good price.

Any recommendation on this topic?

I've seen paul has the D9B whose voltage drop is lower. The only Kingslayer I've built had two OA126 and sounds nice, but I'm not gonna pay what they cost now...
Title: Re: Germanium diodes
Post by: alanp on March 18, 2015, 04:39:20 AM
My D9D's sound nice.
Title: Re: Germanium diodes
Post by: Tkrain42 on March 18, 2015, 05:25:29 AM
I've usually replaced 1n34a with 1n270 with good effect... but... you should know that Tayda has the 1n34a right now for $.24... They're almost always out of stock on these. 
Title: Re: Germanium diodes
Post by: RobA on March 18, 2015, 06:16:52 AM
I've got some D9B diodes that I've been using and they sound good to me as clippers. I've used them for hard clipping and for inline crossover distortion and they worked well in both settings. I can't compare them against any of the other D9x types though since I don't have any others yet.

Tayda 1n34a diodes come with a warning. Many here have had dud batches of them from there. I've had batches where about 5% of them were bad. They do also seem fairly fragile to me compared to other Ge diodes I've got. Those I have that work and measure within spec sound fine though.
Title: Re: Germanium diodes
Post by: micromegas on March 18, 2015, 09:27:29 AM
Thank you guys. I think I'll order some D9B's from Paul. The price is as nice as the diode itself.

I have a couple of Tayda's 1n34A and I've compared them with other 1n34As I had arround. They don't even look the same and, as Rob say, are a ton more fragile.

When I built my Kingslayer (a friend took it from me and now another friend took it from him :) - KARMA) I did a comparison between 1n34As, OA126 and a ton of silicon diodes incluying what Jon (midwayfair) recommended as a "silicon aproximation" to OA126. The OA126 sounded the nicest, but Jon's aproximation was really close, like now-one-except-me-playing-in-my-room-would-notice-any-difference close.
Title: Re: Germanium diodes
Post by: rullywowr on March 18, 2015, 11:53:40 AM
I used to get Tayda diodes, caps, ICs. Now I get them from Mouser so there is no question they are legit.  BAV33 work well in Klones too.
Title: Re: Germanium diodes
Post by: midwayfair on March 18, 2015, 01:11:44 PM
Here are my measured Fv on a bunch of Russian diodes from my stash:

D9B: ~.27
D9V: ~.27
D9E: ~.27 (seeing a pattern?)
D9J: ~.32 (woops)
D9K: ~.32 (oh, ok)
D2i (I think? smaller grey-body diode from the 80s): .32V
D2V: .2V, but these aren't practical for pedals anyway
D312A: ~.25V
KD522B (silicon): .55V (lower than 1N914)

I think I might have more ... Anyway, almost all the Russian detector diodes are indistinguishable for our purposes. Most of them didn't even measure different resistances across them. You can just get whatever's cheapest, but none are an actual substitute for a 1N34A if you really need the slightly higher forward voltage.
Title: Re: Germanium diodes
Post by: micromegas on March 18, 2015, 02:06:36 PM
Quote from: midwayfair on March 18, 2015, 01:11:44 PM
Here are my measured Fv on a bunch of Russian diodes from my stash:

D9B: ~.27
D9V: ~.27
D9E: ~.27 (seeing a pattern?)
D9J: ~.32 (woops)
D9K: ~.32 (oh, ok)
D2i (I think? smaller grey-body diode from the 80s): .32V
D2V: .2V, but these aren't practical for pedals anyway
D312A: ~.25V
KD522B (silicon): .55V (lower than 1N914)

I think I might have more ... Anyway, almost all the Russian detector diodes are indistinguishable for our purposes. Most of them didn't even measure different resistances across them. You can just get whatever's cheapest, but none are an actual substitute for a 1N34A if you really need the slightly higher forward voltage.
Thanks Jon! I think I'll get som D9B from Paul and put them in series and compare against the Kinsglayer my friend has with OA126.
I tried the same with BAT42 and something else (I don't remember well, but it's written somewhere here).

I still have 2 OA126, but those are for collection and don't want to put them in any pedal yet..

Do you remember when you could buy 50 OA126 for 10$? Like 3 years ago? :)
Title: Re: Germanium diodes
Post by: midwayfair on March 18, 2015, 02:10:21 PM
Quote from: micromegas on March 18, 2015, 02:06:36 PM
Do you remember when you could buy 50 OA126 for 10$? Like 3 years ago? :)

Grrr.  >:(
Title: Re: Germanium diodes
Post by: micromegas on March 18, 2015, 03:04:01 PM
Quote from: midwayfair on March 18, 2015, 02:10:21 PM
Quote from: micromegas on March 18, 2015, 02:06:36 PM
Do you remember when you could buy 50 OA126 for 10$? Like 3 years ago? :)

Grrr.  >:(
I know the feeling.
I have a bunch of OA7s I got in a deal with an ebay seller and have started to give some of them away. It's a shame when we surrender to hype... every diy builder should have the oportunity to build at least a diode-based od with germanium diodes once in his life. :)
Title: Re: Germanium diodes
Post by: RobA on March 19, 2015, 03:29:30 AM
Quote from: midwayfair on March 18, 2015, 01:11:44 PM
Here are my measured Fv on a bunch of Russian diodes from my stash:

D9B: ~.27
D9V: ~.27
D9E: ~.27 (seeing a pattern?)
D9J: ~.32 (woops)
D9K: ~.32 (oh, ok)
D2i (I think? smaller grey-body diode from the 80s): .32V
D2V: .2V, but these aren't practical for pedals anyway
D312A: ~.25V
KD522B (silicon): .55V (lower than 1N914)

I think I might have more ... Anyway, almost all the Russian detector diodes are indistinguishable for our purposes. Most of them didn't even measure different resistances across them. You can just get whatever's cheapest, but none are an actual substitute for a 1N34A if you really need the slightly higher forward voltage.

Very useful info. Thanks!