What diodes have I got?

[Beaker]

I got a load of diodes from Bulgaria a while ago, and I have just found a bag of them hiding under my bench I had forgotten about. I'm not sure what they are though.

Russian silicon, very small glass tube, and look just like KD521A, but with coloured bands as follows: brown / yellow / orange / yellow (wide band).

Any ideas guys - they look like the ones in some Civil War Big Muffs.

[rocket88]

I think I have some like that. Can you post a pic so I can compare them to what I got laying around.

[Beaker]

These are them. KD521a at the top with the blue bands, mystery diodes below.



Wide yellow band / orange / yellow / brown.

I'm pretty sure on the colours - the photo seems to reproduce them quite accurately.

I'd love to know what they are, as I want to get some more - they sound great.

Have a  look at Kit Rae's big Muff page - I'm convinced they are the same as some of the diodes in the Civil War Muffs.

[Travis]

Good eye Beaker! The bottom diode does look almost identical to the Civil War diode, but I don't see the brown stripe on the Civil War diode, so I think they are different

[Beaker]

The photo is actually really deceptive - it makes the bands look so obvious.

However, with the naked eye, the orange band looks exactly the same colour as the two yellow bands, and the brown band is effectively invisible against the copper wire underneath. It honestly looks like there are only three yellow bands.

I have got a hunch that they are KD521V. They look like they have three yellow bands on the pics I have seen on ebay listings, and it would make sense if these were used (as well as KD521A) in the Sovtek Muffs.

[rocket88]

Alright man, finally got home and checked the unknown diode against my stock. I can say without a doubt it's a KD521V. They're the Si diodes used in the russian muff. The KD521 A was also used in the russian muffs, but they're blue banded, and the KD521B are black banded, rather then yellow. Great gift btw, they're really hard to come by and when you do they're super expensive compared to what they used to be. I think I've got 600-1000 of each one. They're each slightly different tonally, and in their breakup. The KD521V is one of my favorite clipping diodes.

[Beaker]

Thanks for the confirmation Zach, good to know my hunch was correct.

I've just bought 300, so they should last a while.

I did notice KD521G are still cheap on ebay!