Re: OK WHAT'S THE DEAL HERE?
No need to denigrate us Engineers, we have logical minds that respond well to facts and rational explanations.
Tubes and transistors clip in different ways.
What these gentlemen are saying is true, although in and of themselves, these statements won't help your cause. An Electrical Engineer is taught to minimize distortion and maximize efficiency. This is absolutely the case for Hi-Fi music reproduction, where the goal is to reproduce the source material as accurately as possible. To this end, transistor based amplifiers are more accurate, power efficient, and mass efficient. Everything surrounding a Hi-Fi amplification system is tailored to be neutral with even response from 20Hz to 20KHz. (Speakers, cabinets, amplifiers, DACs, etc.) Transistor Hi-Fi amps are operating in the linear range, minimizing distortion, which is the goal.
Tube guitar amplifiers are NOT operating in the linear range, we want them to clip. This is where Lampy's and Brian's statements come into play. When you are operating an amplifier outside of the linear range, the clipping characteristics of vacuum tubes is quite different than transistors. Solid State devices hard clip the signal, tube devices soft clip at onset of clipping. This can be seen on an oscilloscope, it's not theoretical, or one of those "mojo" things, it's right there in black and white (or green

). Additionally, we use other components in the signal chain to alter the frequency response of the guitar. Guitar speakers are heavily midrage biased, much less treble and bass response than Hi-Fi, guitar cabinets are meant to resonate, not be inert. Heck even guitar pedals are messing with phase and echo and input gain to change the sound.
Interestingly enough, most of our tube guitar amps can trace their lineage back to the Fender amps of the 50's, which were lifted right out of the RCA documents of the 30's, published in order to sell the same tubes in the diagrams! These circuits
were the Hi-Fi amplifiers of the era, but not very good in modern standards. As technology progressed, the ability to more evenly reproduce sound got better and better, and amp design got further and further away from those original circuits. The interesting thing about guitar amps is that they actually
become part of the instrument. An electric guitar is not a complete instrument, you need the amp to complete it. We want the amp operating in non linear range, adding slight distortion and harmonic breakup, even when we play "clean". Simply plug your guitar into your Hi-Hi amp's input and see how bad it sounds.
I am interested in the statement "a transistor and a tube function exactly the same" because that is NOT the case. In fact, unless he is over 55 or so, his education (and mine too) included exactly "0" on tube amplification devices. There's just no reason, when the industries you will be entering have had no use of tubes for decades.