Re: Preamp vs Power Tube Distortion
Please bare with me, I am not claiming I am 100% correct on this but following is my understanding so far, I am not an expert and you should go out and try to read a bit more about it. Theoretical perfect hifi amplification is linear (louder replica of input signal), guitar amp distortion as we know it comes from imperfections of the amplifier for which which preamp, poweramp, transformers and speaker contribute too, changing the shape of the sound if you could look at it graphically maybe thru a graphic equalizer with a LOT of small frequency bands. These imperfections are emphasized by the input level at each stage. Guitar -> Preamp tubes-> Power Amp Tubes -> Transformer -> Speaker
Lets think of an amp with master volume so the power section is not being "Pushed". A clean boost is like a louder guitar with no EQ change that pushes the preamp section so the imperfections (lets call it the character) of the preamp is the one you hear from this kind of distortion, turning up the gain of preamp section will make the tubes to work in bigger current/voltage levels that make its own "imperfections" more pronounced too, but musical as we know.
I understand for old guitar amps there was no separation of level controls for preamp and poweramp, chances are they did not even call these that way, it was a whole amp. So all the elements would interact and feed a bigger input signal to the next stage as you would crank the volume knob. I understand the approach of separated controls for distortion and volume (preamp gain and power amp gain? ) came later and only then people would better understand how much each stage contributes to the tone they like.
I have not ever been able to play with a real tube amp and crank the volume to hear what the power tubes section adds to the sound, but it is my impression most (not all) of the tone metal players like comes from the preamp, maybe because the nuances in tone are not that much, and it is my impression that guys who play sligh breakup and classic overdrive do appreciate what each section of the whole signal chain adds and so that is why they appreciate what a cranked power amp section ads to the tone.
I am myself focusing right now on completing my rig based on tube based preamp in stomp-box size and solid state power amp in a small size too. By not having transformers allows me to have a lightweight, smaller and portable equipment, I am sacrificing only the power amp section as for me most of my tone I am looking for is, imho, coming from the preamp or pedals or speakers. May I be missing something even better by not having a tubed based power amp section? Maybe. but portability was very important to me and that was the approach that better matched my needs.
