[Tim Farrant]

Jeroleen,

I would say that slew rate only really effects the top end of the audio band where the speed of the amplifier has an effect on the ability of the device to reproduce transients.

The "warmth" you speak of is more to do with distortion artifacts. Transformers (depending upon their construction and the type of metal used in the core) can generate harmonic distortions at low frequencies. The effect to the ear is like hearing soft overtones to the fundamental note (given a pure tone). Obviously with a complex waveform such as "music" then the overtones become very complex too.

Tubes can also generate quite high harmonic distortions, depending on the circuit they are in so the combination of tubes and transformers can be VERY warming indeed.

Well that's my slant on it anyway.

Tim