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Character of preamp, power tube, and power transistor distortion

ujonegr at pclprod.meaddata.com (Greg Jones) wrote:

>what is the difference tonally between pre-amp and power-amp distortion?

Preamp distortion sounds buzzy, like mosquitos in heat. It's an insect-attracting sound. It is either on or off. It lacks dynamics. Strike the strings harder, you get additional buzzing, but the character remains the same. Preamp distortion is gritty, grainy, staticy, and lacks dynamics -- the volume level is constant.

Power amp saturation is smooth, natural, dynamic. Strike the strings harder, you get more intense flavor of saturation. The character, not just some amount of buzzing, changes as you change the volume or picking attack. Power amp (and speaker) distortion is fat, natural, round, and soft. It is plastic, compressive, and rubbery. It has a natural screaming sound when you play single notes with high gain. It's more vocal,

Listen to classic rock. A lot of it is played with the amp on the edge of breaking up. But even when a tube amp breaks up, it gets compressed and wrinkled, rather than shattering. It folds, rather than breaking into sharp shards.

Cranking a solid state amp is better than playing purely with preamp distortion.

Almost all the rock guitar you hear on the radio is played through tube amps, using significant power amp saturation.

>Maybe this can best be answered by saying giving an example like:

>"Guitarist X's sound is a good example of pre-amp and power amp
>distortion, while guitarist Y's sound is a good example of a guitarist
>playing without power amp tube saturation."

>And what about hybrid amps that have tube preamps and solid-state
>poweramps. Are there poweramps designed not to distort in order to
>utilize efx in the efx loop without muddying them up?

Using tube preamps with solid state power amps sounds the same as completely solid state guitar amps. This form of hybrid amp is wishful thinking.

Using a solid state preamp with tube power amp probably can sound the same as an all-tube amp. I think having a rectifier tube rather than diodes makes a bigger difference than putting in preamp tubes rather than transistors for distortion. The power amp and speakers is where the real action is at. And equalization throughout the system is very important. Guitar Player Dec. 96 reviewed 4 multieffects units. They concluded that the preamp tube is marketing hype and wishful thinking, because the solid state unit sounded just as real and natural as the units that used a preamp tube.

>Or are hybrid amps' solid-state power amps typically designed to distort

They are, and guitarists crank transistor amps when they use them. Having a speaker helps smooth out the tone, but still, power transistors lack the rubbery dynamics that power tubes have.

>Of course most of us would probably agree that a cranked ALL tube amp
>sounds better than a hybrid and I'm sure power tube saturation plays a


Craig Anderton reports that guitarists cannot identify a tube vs. solid state *preamp* in a blind A/B test. The difference is much more subtle than power tubes vs. power transistors. On the other hand, it would be very easy to identify the tube vs. solid state power amp in a blind A/B test, particularly with a blues tone rather than a Metal tone.

>>>Why not buy an amp like the Subway Rocket that has one channel of clean and one channel of distortion, and if you want to use pedals for more sounds, run them in front of that amp's clean channel.

fatsound at mindspring.com (Stuart V. Carter) wrote:

>This model of Boogie, like most Boogies, derives the vast majority of
>its "second channel" distortion from the preamp tubes. Preamp tube
>distortion does not offer the same level of dynamics afforded by
>distortion created by overdriving power tubes. For certain styles of
>music and for some players this is fine, but for other styles, blues
>in particular, it just doesn't work as well. Blues is a style that
>requires dynamic expressiveness, Experienced blues players know that
>one of the secrets of great tone isn't just the sound of an amp, but
>the feel.

>For all intents and purposes an amp that derives its distortion from
>the preamp tubes will have a very solid state like feel whereas the
>amp that utilizes power tube distortion will have a give and take with
>the player that is dependent on how softly or hard you play. This
>allow for a more emotive, expressive sound and feel which is vital to
>good blues tone.

>A great blues amp should allow you to go from talking sweet to your
>girlfriend, to screamin at your wife just by how hard you play. No
>channel switching required

>It's easy to understand how a player who has never experienced the
>feel of a great amp might have trouble grasping the concept, but
>having owned all manner of amp including several Boogies, I have found
>it to be a fundamental truth.

>Stu/Fat Sound

Different Types of Tubes and Distortion - By Guilherme Mello.

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