Why are the tubes so huge?

[astouffer]

Nobody here must browse the Pass forum 😀

B1 with Korg Triode

 

[Tubelab_com]

I have seen that one. I clicked by mistake while looking for the Germanium Investigations thread. I played with class A germanium amps back in the 60's with the big TO-36 parts found on old car radios.

The Korg - B1 design is very similar to the circuit in the data sheet with some CCS's in place of the source resistors. If I was doing something like that I would use a CCS in place of the plate load resistor on the NuTube and find the tiniest low capacitance mosfet on the planet for an output source follower. The NuTube is a low input impedance, high output impedance device. Buffers are needed to get HiFi type frequency response out of it.

Pete Millett has also done at least one amp with the NuTube. It's somewhere in the "tubes" forum and probably on his web site, but I really haven't looked much beyond the first page of either.

Both are intended for HiFi, not a guitar preamp. I would start with the circuit in the data sheet for a guitar preamp. Then tweak it to suit your desired sound preferences.

 

[mnesarco]

This Thread was very informative to me. Thank you Guys.

 

[daqvin_carter]

This thread reminds me that I am running a low power 845 amplifier from 300HZ up with horns, I really can scale it down to something smaller.

 

[percival007]

Hi Friends,

Is there any physical requirement forcing makers to make the tubes so huge? Can they be miniaturized? Now adays there are mechanical parts inside microchips (gyros, accelerometers....) so why not tubes at the size of a 2000uF capacitor for example?

Does anyone knows?

You can get some big 2000uF Caps .........................

36DX202F450DF2A | Vishay 2000μF Electrolytic Capacitor 450V dc, Screw Mount - 36DX202F450DF2A | RS Components

;-)