Don Pearce wrote:



In another area of amplifier design, damping factors vary enormously from one model to another and yet rates no mention in advertising at all.

I am speaking of guitar amps, where the effective DF may be anything from 100 to 0.1 or lower - making for very audible differences.

Famous valve amps like Marshall and Fender have DFs of about 1 due to use of modest amounts of NFB. Early VOX amplifiers were class A and used no NFB at all resulting if very low DF numbers like 0.1. When VOX released their first SS models, the DF was even lower than the valve ones - due to using a combination of voltage and current feedback.

The same idea is still used in lot of modern SS guitar amps to get DFs of between 0.3 and 2, so mimicking the tonal character of popular valve models.

But makers keep it all a big secret.

How very odd.



Guitar amplifiers are a case apart.


** Sure - where wildly varying damping factors actually have a big effect on sound and makers studiously avoid any mention of it.

While the complete opposite occurs with hi-fi amps.



.... Phil