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slashnull

convervativeguitarists.com

fuckblindteststubesjustsoundbetter.com

iliketoseemyaudiohardwareglowinginthedark.com

... wait now that I think about it I need the loudest EL84 they have in stock ASAP

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Tubes do in fact do something particular when they are used as signal processing elements to create distortion. This is the "tube sound" and is so important in guitar that it's faithfully simulated in guitar-oriented digital equipment.

Also, when the combination of a tube power amplifier, output transistor and speaker is subject to overload, it produces artifacts that cannot be obtained in any other way in an equally compact form factor. Simulating the actual live sound of a little 50W tube combo cranked to the point that it is crapping out is theoretically possible with some non-tube equipment. In addition to the digital processing to model the total physical system (crapping-out tube output stage, saturated output transformer, and clipping speaker), a powerful back end is required to deliver the results of the calculation to reproduce the actual moving air molecules: a hi-fi system rated well into the thousands of watts.

I think it's the odd transharmonic (or total harmonic?) distortion that sounds pleasing if I recall my sound engineering from a zillion years ago, an even THD doesn't sound good.

There is a hypothesis that asymmetric clipping in single-ended tube stages produces even harmonics that sound good. However, asymmetric non-tube circuits (e.g. diodes or whatever) do not have the tube sound (merely on account of doing asymmetric clipping and nothing else). Furthermore, tube power amp sections are often push-pull: symmetric clipping when overloaded. The saturation of output transformer cores is also symmetric.

"THD" is just a summary of all nonlinear distortion of a signal.

It get's even more interesting... The (these days) extremely rare germanium semiconductors sound better than modern silicon semiconducters....so the guys building fuzz and other similar effects are using the dwindling supply of NOS germanium transistors and diodes. Germanium conducts at a lower voltage, sometimes as low as 0.15V vs 0.6-0.7V for silicon.

Nom pe. Opposite.

Sure, just ignore the technical reasons why tubes are better for some applications. From IEEE: http://spectrum.ieee.org/images/archive/images/tubet1.gif

(source: http://spectrum.ieee.org/consumer-electronics/audiovideo/the...)

I find sound creation to be quite interesting, compared to sound reproduction. In a way buying an amplifier is easy. You plug in your guitar and try to find sounds that you like, that fit your vision of what your music sounds or are just plain cool. Just bought a tube amp. Second hand, they are not expensive. There are so many amateur musicians who don't just have the time to use their gear so much that it would start wearing a lot. New features are rare. So 20 year old equipment is often perfectly usable.

Buying guitar amplifiers is hard. Because, anything that sounds different from what you currently use day-in and day-out initially sounds very cool. Then spend a week with it, and you gradually start hearing into it stuff you dislike. Finally, you hate it all together. :)

This is part of the reason for the conservatism. The problem is avoided when people stick to circuit topologies and components from 1940-1960. (Plus extra gain stages for metal: that's what "modern" means).

Let's not turn HN into Tumblr.

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