Maxwell.Fourier, where have you gone?

**Ted Logan** · 12-08-2006, 04:17 PM

It was his only post, but it was golden.

Quote:

Originally Posted by Maxwell.Fourier

The discussion of tubes vs. transistors is interesting but looking at just the active amplifier portion of the system ignores the other 80% of what makes the sound. The designer's choice of capacitors, resistors, and in some cases inductors has a very dramatic impact on the nature of the sound and the frequency and amplitude responses of the amplifier. And last but not least the output transformer has the final say in what comes out of the speakers. Every transformer is a bandpass device and the number of windings, the core material, physical geometry, and percentage of rated capacity it is run out can make dramatic differences in the bandwidth of the transformer. If you construct an (pre- or power) amplifer using MOSFETs with the same relative bias point as whatever tube is in there now (a tube not biased exactly in the center of its linear region will exhibit asymmetrical clipping so the MOSFET needs to be biased at the same relative point on its characteristic curve) and use it to replace the tube section with the same filtering and output transformer you'll never be able to tell the difference. You might say you could hear the difference if you knew what had been done, but if you didn't know you'd never be able to tell, no matter how experienced an ear you have. It's all about the frequency response of the system and the harmonics introduced by the nonlinearities regardless of whether they are created by tube clipping or solid state clipping. I've had tube amps that sounded raspier and buzzier than any solid state stuff I've every had. You can get the wasps-in-a-paper-bag sound out of tubes just as easily as transistors if you're not careful, just like you can get those warm, fat, and responsive tones that clean up nicely out of transistors if you are careful with the rest of the circuitry. Tubes aren't a magic cure-all for bad sounds just like transistors don't automatically sound bad because they are transistors. There's so much more to it than tubes vs. transistors...

Just my 2(sin(pi/4)-cos(pi/4)) cents worth...

Maxwell.Fourier

Why do so many people post once and then leave us?