My homebuilt transistorized amplifier.

Built it back in 2004. I used a midrange speaker resulting in a most tinny sound.

Category:

Howto & Style

Tags:

• homemade
• homebrew
• built
• circuit
• electronics
• project
• electric
• transistor
• resistor
• capacitor
• solder

[soundtrap8]

how many watts does this put out?

[CassetteMaster]

The scamatic said 1.5 watt I believe.

[chrisw71]

Is there a schematic for this amp on the internet?

[CassetteMaster]

I remember I got the scematic for the main amp(not the preamp) off the Net, but I don't really remeber the name of it.

[coondogtheman1234]

ive made a mini amp out of a cheap mini autoscan radio its a tiny boombox but i hacked it into an amp for my ipod and mp3 players, it sounds tinny and its not the loudest amp ive hacked but im gonna do another one soon i have this fm auto scan lantern radio thats loud im gonna hack that one too the fm autoscan radios i think they suck they never stay on the station you want and they sound like crap you agree with me?

[CassetteMaster]

Those radios don't allow you to tune right.

[BadRabbit1776]

One of the best MacGyver Amps I've seen.

[KingCyrix]

Yeah brother! Your like Merle Haggard and George Jones and Elvis Presley and leather face without the mask all rolled into one! You even rap at one time... I don't feel safe...

That said I think many people are missing the point. He just assembled the most Borg like collection of technologies in the most archaic and convoluted way possible. I mean the tech is all nine inch nails looking all the while he's coming at us like strung out Bill Nye the Science Guy with all the product specs.

[drake1351]

lol more bass dude this sound horrible just give up

[lazzer408]

MUSHROOM!!!!!! :D

[Nivicoman]

@Sub40H The output line/Recording head driver transformers of my tape deck are huge for the amount of audio and dc power they deal with (Class A with small audio Germanium transistors) maybe 20 mW audio and 100 mW DC. The stand alone version of this deck has a headphone output which is taken from 10 ohm windings on the transformers. BW is reasonable but we all know the best amplifier is direct coupled all the way through. Even resistor/capacitor coupling introduces phase shift and coloration.

[Sub40H]

@Nivicoman: You are right. Large driver transformers are needed to get a sound quality which is barely "not bad". But still increased eddy currents will kill the high frequency quality. Since a ferrite core tweeter driver transformer plus an iron core woofer driver transformer in the same system is quite impractical, thats why they developed dual power supply amplifier designs I guess.

[Nivicoman]

@TheUncleDougger Because someone has a hobby having more fun building stuff than store brought does not a gay make.

[Nivicoman]

Lower efficiency but vastly better quality would be using a 2N3904 and 2N3055 in a Darlington arrangement. Use a 8 ohm noninductive 10 watt collector load resistor for the 3055 and couple it to the speaker with a 500 or 1000uF cap (collector/ground). Use a 1 Meg pot to set bias around 1/2 supply voltage at the 3055's collector (I used a 12 volt supply 2.5 amp-you know how inefficient Class A is).

[Nivicoman]

@chrisbx1975x The other side of the coin could be if the output Z were really low he could get more power by using a lower impedance speaker without using a higher voltage rail. Old school car stereos were made for 4 ohm speakers simply to get more power with the available 12 single rail supply.

My JVC Nivico stereo console uses single -28 volt rails to get 23 watts per channel into 8 ohms (all PNP transistors so positive is ground).