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?

I think that the sound is more dependant on the tube character that goes into them. I think tube amps tend to have a signature character rather than sound and that is what has been described here. Characteristics meaning lifelike mids, soundatsge, imaging and soft on the extremes.
Yes, tube amps sound different from SS amps Chris. The "Signature Sound" of tube amps to me is palpability, or the fuzz on the peach effect. Yes, SS is quieter and has better bass definition, and I've heard smooth SS, but I've never heard SS have the "fuzz on the peach" palbability of tubes.

Odd ordered harmonics have absolutely nothing to do with loudness or SPLs.( ( They WILL give you a massive headache however. Both of the above sites contain definitions of odd-order harmonics. The only correlation between them and loudness is that overdriving a solid state amp produces much more, and overdriving a speaker system can cause a lot of intermodulation and/or saturation of the crossover. One of the reasons amps sound more accurate now days is that the components(capacitors, resistors, even wire) used in manufacture have been vastly improved upon. Unfortunatly the TUBE manufacturers have not been keeping up. The tubes made in the 40's through the 60's are still the most lucid/transparent/accurate on the whole. As I stated earlier: Read what the experts that use LIVE MUSIC as a standard(both amplified and acoustic) have to say on the issue. Become very familiar with live music yourself, then judge the accuracy/staging/imaging/sound pressure levels of your system accordingly. Of course: everyone's goal isn't the same. Some folks are happy to have their eyes tickled. If everyone had the same tastes; this would be a very boring world. If I can't close my eyes and pretend I'm at the original recording venue(NOT the band playing in MY room, and not all recordings contain enough encoded info to allow this), it's hard for me to even tap my foot.
Different tubes have a basic signature sound, EL34, 84, KT 88, 6550, 6SN7, etc. You can characterize the sound of tubes versus SS but there are some manufacturers who have designed tube components to be faster, more dynamic, etc. The 6H tube comes to mind for me. That being said, go hear an old Eico with the EL84 tube and hear what a fluid mid-range really sounds like. I recently heard a modified Dynaco ST-70 and it was wonderful sounding. No SS amp that I have ever heard can do what these tube amps can do. I have an old Lafayette KY-550 and it is an outstanding sound amp in stock form. The closest I have heard to a tube amp that is not a tube amp is the Gilmore stereo power amp. Not as 3D sounding but very musical in the mids.

Happy Listening.

Rodman99999, it is easy enough to demonstrate that in fact odd-ordered harmonics are indeed what the human ear looks for as a loudness cue. Its an easy test.

Get a sine/squarewave generator, an amp, a speaker and a VU meter. Run the sine through the amp and speaker and set the level so the VU meter reads 0VU (the meter will be across the amp terminals, this is not a loud test but it can be if you want). Now run a squarewave, and set its level such that is sounds to be at about the same level as the sine wave. You will find that the equivalent level is in the neighborhood of -20 to -24 db to get the same effect of volume. That's at least 1/100th the level of the sine wave!

Try it!