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Things you can do with diodes

(lcamtuf.substack.com)
325 points zdw | 2 comments | 03 Nov 25 23:49 UTC | HN request time: 0s | source
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dietrichepp ◴[04 Nov 25 00:27 UTC] No.45806185[source]▶
Conspicuously absent are some of the analog circuit applications. Here are three of my favorites:

1. Frequency mixer, used for heterodyning, important in radio, so I hear. https://en.wikipedia.org/wiki/Frequency_mixer

2. Log converter, where the output voltage is proportional to the logarithm of the input voltage. https://electronics.stackexchange.com/questions/374440/log-c...

3. Diode ring, which provides variable gain, used in analog compressors like the Neve 33609 (I have a clone of the 33609, and I’m very fond of it)

Think about this: if you have a nonlinear device like a diode, then the dynamic resistance changes depending on the operating point. If you modulate the operating point, you’re modulating the dynamic resistance.

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1. beckler ◴[04 Nov 25 01:54 UTC] No.45806695[source]▶
Kinda interesting to hear about. I have a 500 chassis I’m slowly working on filling. I’m between the RND 535 or 543, and had never heard of a diode bridge comp before looking at the 535.

What kind of 33609 clone do you have?

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2. dietrichepp ◴[04 Nov 25 04:21 UTC] No.45807393[source]▶
I have the Heritage HA-609A. I considered going 500-series. Maybe some day in the future. For now, I have two preamps and the HA-609A in a 4U rack, and most of my other gear is in storage. Keeping things light.