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Transformless amplifier

jack121

New Member
Hi Thanks for reading.
I want to build a simple discrete amp with the absolutly lowest number of components possible, preferably a two stage with driver transistor and output transistor, as cheap as possible, i don't want to spend any serious money, just a few bucks.
As power supplies are expensive, do you know of any design that runs off the mains ac 240volts, just a bridge rectifier and smoothing capacitors, no transformer.
A cheap and cheerful amp for music reproduction that works and is stable, not concerned about hi-fi sound or super low distortion
Thanks
 

Papabravo

Well-Known Member
Hi Thanks for reading.
I want to build a simple discrete amp with the absolutly lowest number of components possible, preferably a two stage with driver transistor and output transistor, as cheap as possible, i don't want to spend any serious money, just a few bucks.
As power supplies are expensive, do you know of any design that runs off the mains ac 240volts, just a bridge rectifier and smoothing capacitors, no transformer.
A cheap and cheerful amp for music reproduction that works and is stable, not concerned about hi-fi sound or super low distortion
Thanks
The definition of insanity is asking the same question on multiple forums expecting more congenial results. Electronics is pretty much the same in all corners of the universe.
 

For The Popcorn

Active Member
But he used many of the KEY words!

>Cheap

>Simple

>Little

>Cheerful (new one on me)

>Quick

>Dirty

So it must be possible
 

danadak

Active Member
You can build a zero component amplifier, and it is pretty safe -

1657646768602.png


Regards, Dana.
 

gary350

Well-Known Member
1N34 diode radio plays music and very low number of parts. NO power supply. I received 1 of these for my birthday 1958. I built 1 in electronic class 1970. Diode is 1N34. I learned just from experimenting 2 diodes in parallel music is louder. Maybe diode resistance is less with 2 in parallel??? L1 & C1 are the resonance circuit for radio frequency that you want to receive. It will only power 1 ear plug type ear phone. Antenna is a 3 ft long wire with an alligator clip on the end. When I was 8 years old I had good hearing I could hear the music play fairly loud. I'm not sure what requirements are for the ear phone. When I was in high school stores had this same type radio that picked up TV sound no video but 6 months later no more for sale. Circuit drawing shows ground but factory radio had no ground and it works.

1N34-Radio.jpg


Here are a few bucks.

bucks.jpg
 
Last edited:

cooperhow

New Member
Hi! Could you explain more on your requirement? It would be helpful if you could let us know the voltage, ohms of the amplifier, power output, DI or AI, and terminal product. Good luck with the project!
 

Pommie

Well-Known Member
Most Helpful Member
1N34 diode radio plays music and very low number of parts. NO power supply. I received 1 of these for my birthday 1958. I built 1 in electronic class 1970. Diode is 1N34. I learned just from experimenting 2 diodes in parallel music is louder. Maybe diode resistance is less with 2 in parallel??? L1 & C1 are the resonance circuit for radio frequency that you want to receive. It will only power 1 ear plug type ear phone. Antenna is a 3 ft long wire with an alligator clip on the end. When I was 8 years old I had good hearing I could hear the music play fairly loud. I'm not sure what requirements are for the ear phone. When I was in high school stores had this same type radio that picked up TV sound no video but 6 months later no more for sale. Circuit drawing shows ground but factory radio had no ground and it works.

View attachment 137851

Here are a few bucks.

View attachment 137852
We called that a crystal set. I built one when I was 10 and listened to the moon landing on it.

Mike.
 

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