Tube vs. Solid State for Dummies?


Hello everyone... I just discovered this terrific site, & have been perusing the multitudes of posts--very informative! Here's my question: Can someone explain--IN SIMPLE TERMS!!!--the difference in how a tube amp produces power vs. solid state, and why tubes have so much less current (while sounding warmer)? Here's my understanding (possibly inaccurate)of solid state...The capicitors are pouring energy to the output stage, and the flow of that energy is constricted by the output transistors. The transistors, responding to the input signal from the preamp, either constrict or release the flow of that energy/electricity to the speakers. I assume this is where the "power" is produced--that by clamping the flow, the pressure is increased (like putting your thumb over the hose). Is this true? On this point, how do tube amps do it? How does the tube (coil, collector,grid) upon seeing a very small amount of electricity, produce the "power" to move and dampen speaker drivers? Furthermore, can someone clarify the voltage/current relationship in all this? One of the definitions of high quality regarding amps is their current capacity, however this rule must not apply to tube amps, as they are low current, yes? Any feedback is appreciated, and thanks again for the great forum!
earhertz

Showing 1 response by jcbtubes

Dchace- Be careful not to get caught up into the "numbers game" associated with the current spec most often noted for ss amps. Though it may offer a relationship to the relative size of the power supply, and the number of output devices (and consequently output impedance and dampening factor), it offers no real indication to sound quality. As for power, remember that tube amplifiers use much higher voltage rails compared to ss. Power is voltage x current. The output transformer acts to impedance match the high output impedance tube stage to the low impedance speaker. The exception is the Output TransformerLess (OTL) tube amps that couple directly or through a capacitor bank to the speakers. Check into some audio amplifier design books for a much more detailed description for both ss and tube circuits. Goodluck.