Electronically, tube components usually have different gains and transfer functions from transistors. However, as a designer, you usually take this into account and design around the characteristics of the devices you choose to use. Any competent engineer should be able to produce (within a given abstract specification) two amps of (say) the same output performance in terms of wattage, or THD, or RMS power figures. So in theory, you could have two amps back to back with the same spec, but using different technologies to build them

Would they sound different? I woud be inclined to say (given the above criteria) no, they shouldn't. I won't bet my shirt on it, though - as an example, I have always preferred the sound of a tube based guitar amp over transistor amps without being able to say why; in the house I have never listened to anything other than transistorised systems, so I can't comment.

I think there is an indefinable quality of tone to tube amps, and as an electronics engineer I should be able to explain why, and I can't. Maybe I'm not as hot as I thought I was...

This debate has actually been raging on and off in the pages of Wireless World (an influential semi-professional UK electronics magazine) for some 30 years, and nobody (to my knowledge) has come up with an irrefutable answer.

One of the few remaining Mk1 owners... #00015