Understanding Ring Modulators (Physics article)

[Rockhorst]

I'm toying with the idea of making some pedal/effects based education kits to use in my physics class room. It's potentially a great way to get kids more involved in the subject of electricity and electrical systems (as VFE has also clearly demonstrated). Anyway, this week I received the latest issue of The Physics Teacher and one of this month's freely readable articles discusses ring modulators and specifically the Moogerfooger MF102. How cool is that Caveat: it doesn't discuss the actual electronics, but goes into how ring mods shift frequencies around.

Read it here
(there's also a downloadable PDF available on the same page)

[somnif]

I've often wanted to play with clipping diodes in the "dip LED in liquid nitrogen to see its color change" physics lab.

I have no idea how the logistics of it would play out, but if I'm ever rich enough to afford a 5L dewar and am waaaaaaay too bored, I am going to do it.

No idea what, if anything, it would do tonally, but... I gotta know. 

[Rockhorst]

I can see a 'dip your MoogerFooger in liquid nitrogen' - article in my future...Cryopedals, the new rage.

[reddesert]

Huh, we never got to do anything so pedal-worthy in physics lab!  (We did fry several op-amps, learn breadboarding and some electronics, which I have been coasting on ever since ...)

The voltage drop (band gap) of a semiconductor gets larger as it gets colder, for ex https://ecee.colorado.edu/~bart/book/eband5.htm, so as you immerse your clipping diodes in LN2, your circuit should get louder and cleaner.

LN2 is a nuisance to deal with, but a thermoelectric cooler can get you well below zero with care. Be the first pedal maker on your block to put a heatsink the size of a 125B on your pedal board.

[somnif]

Oh god, imagine the Klon snobs if it comes out that THE perfect mystery diode sound can be found at 78 kelvin.

[reddesert]

Oh god, imagine the Klon snobs if it comes out that THE perfect mystery diode sound can be found at 78 kelvin.

Haha!

What the world needs now is the Cryobender. It's time for someone to use a microcontroller to thermally regulate a germanium-transistor pedal for consistent performance.

As I write this, I'm surprised that it hasn't already happened.