Hi.....
I am new to this website. I have to design the Audio amplifier with transistor. pls give solution to the following specification.
sterio Amplifier.
Wattage: 50Wrms
Input resistance: 50K ohm
Amplification factor: 20
Output resistance: 4ohm.
signal to noise ratio:<1db
Powersupply:36VDC.

pls give immediate solution.

 

When you say "please give immediate solution," what exactly do you mean? Is this a homework assignment which is due right now?

 

Any limit on quantities of transistors used?

 

Another Q would be - what type of transistors to use?

US-spec transistors aren't available everywhere. Europe and Asia seem to have different kinds available.

 

The signal to noise figure is interesting - is this because the power supply is unfiltered, or is the signal source Edison wax cylinders?

 

The signal to noise figure is interesting - is this because the power supply is unfiltered, or is the signal source Edison wax cylinders?

Heh, agreed!

 

The output noise level must be almost as high as the signal output level.
I think a pink noise generator must be included for it. Then it needs an audio mixer at its input.

50W into 4 ohms is a sine-wave with 40V p-p. From a supply of only 36V then the volume must be turned up too high to make 50 Whats worth of square-waves.

I think the spec on another website says it must have a class-A heating output.

 

A single-ended supply of 36VDC would allow for 18V peak.

50 watts peak would be 14.1V, with enough left over for headroom.

14.1V * 0.707 = 10V = 25 watts RMS.

An S/N of >1dB would be a slightly better spec? Please provide immediate response.

 

I think the spec on another website says it must have a class-A heating output.

What website are you referring to?

 

Peak power is measured in Whats. I thought the amplifier has a rating of 50 Watts.

I chat on 6 electronics chat sites. This thread is on a couple or on a few of them like many NOOB threads are. Sometimes different students in a class have the same question on different websites.