18
by Dr Tony Balls_Archive
So one thing i've been thinking about a lot lately is what makes a classic amp sound like the enjoyable classic amp that we all love, and can it be repeated in a small format. FM Steve got me started on this a while ago when he brought up the idea of creating an entire amp with subminiature tubes (like the zvex nano). Subminiature or not there's a few things that are different, and perhaps key, in most mini/lunchbox/whatever amps compared to a standard big boy like a tweed Bassman/JTM45:Push-Pull - Most amps that we use regularly are push-pull config, which is necessary to produce more power, but also affects the sound quite a bit. Single-ended amps like a champ, tweed Princeton, AC4, etc have a grindier/fizzier distortion when they're turned up. The ZVEX Nano is an example of this as it is single-ended as well. Push-pull amps tend to have a more crisp, crunchy distortion.Phase Inversion - Phase inverters are necessary for push-pull and contribute to the sound of an amp, and its a big reason why a tweed Bassman sounds different from a tweed Pro. When I do see mini amps that are push pull (like the Wangs amp Elisha posted about) they often have different phase inverters than most common amps. This could affect the overall sound.Pentode/Triode Output - Almost every mini amp I see has triodes as the output tube(s) instead of pentodes, but like *every* major amp ever has pentode outputs for more power and efficiency (EL84, 6V6, 6L6, etc). You see a lot of big amps nowadays that are 30W but have like a "5W" mode and thats when they switch the pentode power tubes to operate as triodes. It makes for a lot less power but it doesnt sound equal. What I need to do is a) stop being so busy, and b) step up and try an experiment where I make a mini Bassman that ticks all of the three boxes above (EF86 outputs?) and see what happens. The goal being can you make a mini version of a normal amp and have it sound the same.