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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
bigkidz
3,413 posts
 
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.

atmasphere's avatar
atmasphere
12,039 posts
 
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!
rodman99999
6,206 posts
 
My contention here would be that the square wave, being an irritant and obnoxious to the listener, might be PERCEIVED as louder. Same reason most people would get "listener fatigue" sitting in front of a system with a lot of IM distortion. Ah- OK: "loudness cue", not actual loudness?(just re-read your post) Not that the sine wave and square wave would deflect an SPL meter to different levels at the same power, but that the square wave would be perceived to be louder? Are we saying the same thing here? I'm REALLY not intentionally being obtuse....Honest!
atmasphere's avatar
atmasphere
12,039 posts
 
Rodman99999, its OK. Square waves are by definition made up exclusively of odd-ordered harmonics of the fundamental waveform (that's why they can sound so obnoxious). Maybe I should have mentioned that earlier.
rodman99999
6,206 posts
 
That's funny: I always thought of the top and bottom of the waveform being flat as DC(simplest terms), as in while a SS amplifier is clipping. Ya learn something new every day
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