I was just having a bit of fun. If class a operation was an actual concern for me I’d likely need to know.
Amplifier Specification questions
I understand the differences between different classes of amplifiers. Most common amplifiers are Class A/B. Does this mean that all class A/B amplifiers operate in Class A to some point then switch over to Class B when they hit a predefined threshold by the design of the manufacturer. Do some so-called Class A/B amps only operate in Class B? My power amp is designed to operate up to 18 watts Class A before changing class of operation. I assume this number is in 8 ohms. My amp is rated at 150 watts into 8 ohms and 300 into 4 ohms. Does this mean that Class A rating will double to 36 watts in 4 ohms or will it stay at 18 watts regardless. What's funny is I was thinking I needed more power because my meters were always pretty well deflected but after looking closer, I realized the meters were on the 5-WATT scale instead of the 150-WATT scale. I can't believe I never noticed that before.
@steve59 If the bias point is properly set the transition is completely inaudible. I wouldn't worry about it :) |
The amplifier bias current determine the output power of class A operation. For example, an amplifier can provide up to 8 Watts of class A power @ 8 ohms load before it switch to class B operation, the current at the output is 1A (P = (I*R) * I ), if the output current over 1A it will switch to class B. Therefore @ 4 ohms load, the class A power is up to 4 Watts. |
@curiousjim You got to love the way Hegel answers our questions. 😆 |
I actually sent an EMAIL to my amp manufacturer earlier today and they already replied back. They claim my Coda #8 V1 does 18 watts class A into 8 ohms and around 12 watts Class A into 4 ohms. This corresponds to what @swede58 said with his Pass amp. Thanks for everyone's help on understanding this. |
@willywonka Wrote:
Yes! See article below: Mike |
So, my Cayin A88T, (8 ohms: 22 wpc triode/45wpc ultra-linear), using the 16 ohm taps yields ____? Class A amps. https://6moons.com/audioreviews/cayin/a88t.html btw: Only model 1 has 16 ohm taps, later versions are still the same 8 ohm rating, only 4 or 8 taps provided. thanks for any enlightenment Elliott |
@swede58 I know Ohms law but it doesn't address all my questions. I am a retired electronic tech by trade. |