When tube production ends one day...

telemnemonics

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If and when tube amps become extinct replaced by solid state modelers it won't matter. Much like we compare the differences between hand wired and pc board tube amps that generation will be discussing old school solid state vs impulse response technology never knowing the glory of what was.
Or maybe rather than everyone embracing models of toobs, vintage NOS MOSFETS will be the hot ticket?
 

Phrygian77

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Keith Richards will still be calling the shots, then. I predict tubes.

keef5.jpg
 

Asmith

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Weber and others sell octal, plug-in, solid state rectifiers, but that doesn't provide context for solid state signal tubes. The plug-in may have resistors for voltage drop, but other than that it's just diodes that can handle HV and it's super simple. You can make one yourself.

Replicating something like a 12xx7, 6V6GT, or 6L6GC is another matter. Coming up with solid state components that can take HV in a circuit that replicates a signal tube structure is difficult.

For collectors of the Zenith Trans Oceanic and similar radios, there's a cottage industry that's making solid state replacements for the 1L6, 50A1, 1R5, 1U4, 1U5, 1S5, 3V4, 0A2, and 0B2T miniature tubes. These radios operate with a maximum B+ of 90 Volts, so these tubes are more doable than trying to replace a 6V6GT that a Deluxe Reverb hammers with 450 Volts.

The closest SS tube replacement I've come across is high voltage depletion mode MOSFETs, like the LND150. I've used a couple in compact amp builds in the first gain stage where everything is class A, clean amplification. I don't know how it would perform in a clipping stage but not tube like. You also can't drop one straight into a 12xx7 spot because they need a lower resistance source (cathode) resistor. Perhaps with some additional components they could drop straight in in place of a tube and sound ok but I don't think it's the likely solution.

I think if replacements for these valves come along it will either be variant of the NuTube technology or it will be done with modelling.
 

Phrygian77

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@Asmith with a max. dissipation of .74W and Vgs max of +/-20V, those are significantly limiting factors, especially the latter since preamp tubes can swing more than twice that.
 

Asmith

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@Asmith with a max. dissipation of .74W and Vgs max of +/-20V, those are significantly limiting factors, especially the latter since preamp tubes can swing more than twice that.

Someone could probably design a MOSFET that's more suitable as a drop in replacement for preamp valves, even changing the package from a TO-92 to a TO-220 would go a long way to increasing the max power consumption.

Still probably not the way forward because of distortion characteristics, etc.
 

RetiredUnit1

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Quantum computers will be able to model not only tubes, but different manufacturers of the same tube. And they won't need to be programmed, they'll be programmed to listen to the sounds and learn them.
 

Phrygian77

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Quantum computers will be able to model not only tubes, but different manufacturers of the same tube. And they won't need to be programmed, they'll be programmed to listen to the sounds and learn them.

This sounds worryingly like the sort of thoughts that would make you edge away if conveyed to you by a stranger on a park bench.
 




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