retrovalves

[egan.]

wouldn't this turn your expensive tube amp into a solid state amp? Kind of defies the purpose. Or am I missing something?

I think what you're missing is that IF they sound close to tubes then you have something with a longer lifespan and greater reliability. What everyone is hoping for is lower upkeep cost with comparable tone. If they make your mesa sound like a warhead then you're right but then no one will buy them.

 

[Shinozoku]

It's a little pin-based clipping circuit using LEDs (of different frequencies in some, it looks like) possibly with another type of diode to create tube-like asymmetrical clipping.

Sweetness

 

[Simon Dorn]

wouldn't this turn your expensive tube amp into a solid state amp? Kind of defies the purpose. Or am I missing something?

That's exactly what it would do!

The power pentode Fetron (the SS replacement of the vacuum tubes including the 6L6) has been around since the 60s. They aren't really made too much anymore as valves where completely phased out, but they do exist.

Here's the original Info. A bit long, but interesting, maybe...?
http://www.ko4bb.com/Manuals/09%29_Misc_Test_Equipment/FETRON_Solid_State_Vacuum_Tube_Replacement.pdf