Question about Class-A Amplifier.

[Brownstocker]

hi there
actually i have a class-A amp which is very popular in internet and it's some how i like it and with just some modifications it's gonna be hi-fi in addition to it's extraordinary low cost.
but the PROBLEM is the power dissipation is maximum when there is no signal so i wanted instead of using a complementry output or AB push pull and a way from crossover distortion i was thinking what if used a transistor as a switch for the supply controlled by the input signal where if the input is quite enough it's applied to a rectifier then it's used to either ON the transistor and connect the supply or OFF and no supply .

finally when there is a signal there is power and no signal no power.
so what do u think guys

2N3055 Power Amplifier

thanks for reading.

[Zen Mod]

you already have power switch on it

better use your energy to find everything about origin , and how to make it better

The Class-A Amplifier Site

[Brownstocker]

i'll give it a try.
but seems good to me.thanks

[CBS240]

Hi

Have you ever thought of using a tracking power supply? Something like cascoding the output stage with a class D amp.

[Brownstocker]

well...i don't know about it but gonna be happy if you show me how or lead me to know how ??

[tiefbassuebertr]

Originally Posted by Brownstocker

hi there
actually i have a class-A amp which is very popular in internet and it's some how i like it and with just some modifications it's gonna be hi-fi in addition to it's extraordinary low cost.
but the PROBLEM is the power dissipation is maximum when there is no signal so i wanted instead of using a complementry output or AB push pull and a way from crossover distortion i was thinking what if used a transistor as a switch for the supply controlled by the input signal where if the input is quite enough it's applied to a rectifier then it's used to either ON the transistor and connect the supply or OFF and no supply .

finally when there is a signal there is power and no signal no power.
so what do u think guys

2N3055 Power Amplifier

thanks for reading.

I would not prefer an intelligent and comfortable solution, because the cost is too high and also you have not easy design.
I would introduce a high quality switch for two values of idle current; one of 20-30 mA (class AB for Pop/Rock and background music), and one of pure Class A (the currently value) for nearest perfect sonic quality.
An another solution it could be, to introduce a separate power supply for the output stage; but variable through switching the transformer windings (e.g. 4 voltage levels). At low volume, the power loss can then be kept smaller and if you want louder to hear another voltage value you must select, which is higher.
For this one to perform automatic (depend of the peaks in your music program) I haven't a solution, because I must then develope Class G or Class H. I don't like such solutions, because you have still the possibility of bi-amping - pure class-A for the upper frequency range and Class AB (good used amp e. g.) for the lower aera. This is the royal way in most cases

[Brownstocker]

Nice solution too..
i think i may use the separate power supply solution because it's the simplest.
or to use the bi-amping that's good too.but here in bi-amping the problem is i never design an amplifier before so i may guess how it gonna be but not sure of that..??