Paperw8 -
Voltage ratio in electronics is, and always has been 20log(v2/v1). Pretty much anything other than power is always 20dB(k2/k1) including sound pressure, sound level etc.
-3dB of voltage means 0.708 of a value. 12dB means ratio of 4, 20dB i ratio of 10 etc. All electronic equipment is scaled that way (oscilloscopes, multimeters, oscillators, dividers etc.). When you press +20dB button on the oscillator output will always jump tenfold. ALWAYS. I've never seen another definition and I'm long, long time in this business.
Also first order has always been 6dB/octave (20dB/decade). That's how every signal filter is defined etc.
As for power cord. What you describe is average value. Amplifier might take 10A on average but it will be taken in narrow spikes of 100A or more, causing 10V drop on your 0.1ohm power cord equivalent to 20% drop in max power.
Capacitor inside is not discharging faster. The problem is that it discharges very little. If voltage drops from one peak of 120Hz full wave to the next only 50mV (ripple voltage) and amplitude is 50V then charging will be done only in arccos((50V-50mV)/50V)=2.6deg. Charging pulse will be 16.6ms*2.6deg/360deg=0.12ms. Pulses will be a little wider because of all inductance in the circuit but as Atmasphere said - in millisecond range.
Width of the pulse depends on the ripple (voltage drop) and ripple depends on the load. It is in a sense fixed frequency switching power supply that is polluting mains. Current spikes have high frequency content that propagates thru voltage drops to every other component on the same mains. Shielding and filtering becomes extremely important.
Jeff Rowland talks a little about it here: http://jeffrowlandgroup.com/kb/questions.php?questionid=144
As for tubes - I built 100W EL34 amp when I was 15 but vaguely remember that tubes need to be heated. This is the double duty Almarg mentioned and can be demanding one - at this moment Atmasphere ears are getting red because his amps (one of the best in the world) waste 90% of power on filament of current hungry tubes (2.5A per tube and there is a lot of them). If not for that, I would buy this amp in a jiffy.
Voltage ratio in electronics is, and always has been 20log(v2/v1). Pretty much anything other than power is always 20dB(k2/k1) including sound pressure, sound level etc.
-3dB of voltage means 0.708 of a value. 12dB means ratio of 4, 20dB i ratio of 10 etc. All electronic equipment is scaled that way (oscilloscopes, multimeters, oscillators, dividers etc.). When you press +20dB button on the oscillator output will always jump tenfold. ALWAYS. I've never seen another definition and I'm long, long time in this business.
Also first order has always been 6dB/octave (20dB/decade). That's how every signal filter is defined etc.
As for power cord. What you describe is average value. Amplifier might take 10A on average but it will be taken in narrow spikes of 100A or more, causing 10V drop on your 0.1ohm power cord equivalent to 20% drop in max power.
Capacitor inside is not discharging faster. The problem is that it discharges very little. If voltage drops from one peak of 120Hz full wave to the next only 50mV (ripple voltage) and amplitude is 50V then charging will be done only in arccos((50V-50mV)/50V)=2.6deg. Charging pulse will be 16.6ms*2.6deg/360deg=0.12ms. Pulses will be a little wider because of all inductance in the circuit but as Atmasphere said - in millisecond range.
Width of the pulse depends on the ripple (voltage drop) and ripple depends on the load. It is in a sense fixed frequency switching power supply that is polluting mains. Current spikes have high frequency content that propagates thru voltage drops to every other component on the same mains. Shielding and filtering becomes extremely important.
Jeff Rowland talks a little about it here: http://jeffrowlandgroup.com/kb/questions.php?questionid=144
As for tubes - I built 100W EL34 amp when I was 15 but vaguely remember that tubes need to be heated. This is the double duty Almarg mentioned and can be demanding one - at this moment Atmasphere ears are getting red because his amps (one of the best in the world) waste 90% of power on filament of current hungry tubes (2.5A per tube and there is a lot of them). If not for that, I would buy this amp in a jiffy.