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Tube amps have a signature sound

Hi folks, this is a bit controversial issue. We all know that nowadays none of the tube amps exhibits the "typical tube sound" (what is the typical tube sound anyway?). If someone says: tube amps have a signature sound, others would say that this signature sound is not typical to tube amps. Well, imho there is something with many tube amps (pre and poweramps). They sound quite fluid, especially in the midrange. The midrange itself is often a bit bigger and more forward than the typical solid state amplifiers. This midrange has also a certain "natural" quality (harmonic richness?). Of course there are tube amps that sound like solid state and solid state amps that sound like tube amps, but in the end I have to admit that many (or most) tube pre and poweramps have a "signature" sound that is somehow related to implementation of tubes in the circuitry. I think that this is also the reason why some manufacturers prefer tube over solid state circuitries. What do you think?

Chris
dazzdax
atmasphere's avatar
atmasphere
11,760 posts
 
Rodman99999, the clipping of an amplifier does produce a square wave, and those 'corners' are where the odd harmonics reside.

If you compare a tube amp to a transistor amplifier when both are clipping, the much harder clip of the transistor amplifier is visible on any oscilloscope and the obviously higher quantity of odd-ordered harmonics is easy seen. This is why transistor amplifiers have a harsh overload character and also why most guitar players prefer the smooth overload of tube amplifiers.
rodman99999
6,109 posts
 
And that's why tube amps seem to play more loudly than SS of the same power rating(without giving the listener a headache)- soft clipping. You're preaching to the choir. One day(if I win the Lotto) perhaps I'll be able to afford to go OTL. Of course my listening room gets quite warm in the summer with no more tubes than I have in the system now. ALAS- champagne taste and a beer budget!!
amfibius
282 posts
 
Kurt Strain - love your reply and was hanging on to every word. Had to re-read your replies a couple of times before I finally got it.

Another factor worth mentioning is that the input impedance (Zin) of a typical valve power amplifier is usually about 100kOhm. A typical SS power amp is usually about 20kOhm.

This means that the valve amp will require less current to tickle the valve into action. Depending on the output impedance (Zout) of your preamp (the ratio of preamp ZOut / poweramp Zin determines current flow) - you will find that power amps with lower Zin are more resolving of low level signals. Which may be another explanation why I have observed that valve amplifiers seem to resolve more detail and create a better soundstage.
mingles
795 posts
 
Bigkidz, I've biamped with SS on bottom and tubes on top. The sound was nice, but in the end, it was more of a pain than it was worth... four PCs instead of two, two pairs of ICs instead of one, extra space, extra heat, clutter. I was glad to dismantle it. It was overkill with little sonic benefit. -Mark
rodman99999
6,109 posts
 
Bigkidz- If you bi-amp correctly, you'll never go back. For instance, read this: (http://www.avguide.com/products/product-1672/) Click on the review. I'd been using a Dahlquist DQLP-1(slightly modded over the years) since 1981 with great results. The time-alignment that the TacT provided took everything to a whole new level, and still proved as transparent as the Placette Passive Linestage I'd used last with the Dahlquist.
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