My homebuilt transistorized amplifier.

[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]

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]

Have you noticed cassette recorders prior to about late 70's often used a push pull arrangement with interstage transformer driving 2 germaniums in the 2SB series and a 2SB series on the primary of the interstage.Then a centertapped output transformer. Usually 80-8 KHz BW. Often the recording was also done through those transformers. I had an Emerson table top stereo with AM/FM/phono/8 track and it had RC coupling no transformers. Problem was it had noticeable crossover distortion at low volume.

[MrJasonnajman]

just love that dang music!

[dharn1]

he is probably very good with electronics but why did he build such crap

[Sub40H]

Dude, use a TDA 2040 instead. The size of the mains transformer does not look more than a 12-15VA one, which means the output power is in the range of 8-10W RMS. Transistor amplifiers are used only when power in excess of 100W RMS is needed.

Also that small driver transformer that you used in your preamp, ruined the quality of sound output just as the broken speaker. Now dont get angry, it was a nice first try though.

[Nivicoman]

@Sub40H Yeah that transformer is too small to be hi fi and having an output transformer degrades it even worse. Driver transformers can be good if they are large enough. My JVC Nivico stereo console has large driver xfmrs along with capacitors coupling the outputs to the speakers and sound quality is not bad. The driver xfmrs are twice the size of the output used here. Then the Reel to reel tape deck has line output/record head driver xfmrs even more massive and they only deal with maybe 50 mW.

[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]

@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.

[feketejani1]

WTF speaker hehehehehehe XD :PDXDXD

[Gangster88232]

Horrible construction.

[TheUncleDougger]

he is sooo gay

[Nivicoman]

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

[777Zuka777]

бля ещё оджин думает что он пиздец куртой типо )) динам наворн в первый раз видит )) думает нихуя какой огромный))

[handsupbud]

This will never catch on.

[minisoft1]

wow.. get an ipod or some sort of mp3 player... come on now..

[ThePhonograph]

what is the scamatic as im 14 ad intrested in eletrionics

[kami07860]

search for schametic over internet after you have choosen the IC..... to make amp

[SheldonStankevitz]

It's a blueprint of the IC (Integrated Circuit)

[TheBlankDeck]

@ThePhonograph wat a coinidence. me 2 except i turn 14 feb 4th

[lazzer408]

Infected Mushroom!!!!! WOOOOOOO

[maddfix]

this is total chaos:|...rebuild it....using regular pcb.

[chrisbx1975x]

your voltage rails will give you an idea of how loud it can go, or supply voltage if it's single... assuming you have enough gain, which you likely do using that preamp.

25v rails +/- total of 50volts will give you 25 watts into 8 ohms. with 10v rails or 20v total you can get about 4 watts into 8 ohms. yes the 3055s he's using can handle a lot, but it depends if the main supply voltage will allow the ac signal to swing that high.

awesome audio setup btw. crazy, messy, perfect.

[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).

[soundtrap8]

how many watts does this put out?

[CassetteMaster]

The scamatic said 1.5 watt I believe.

[soundtrap8]

cool. im building a 2 watt amplifier right now for a speaker im gonna put in my backpack. is it reasonably loud?

[rockymountainradio]

you diden;t mean to say 15 watts by chance did you? would have thought that with 2N3055's that might be more like it

[mrroby123]

this is the worst speaker ever but the amp could be cool, rebuild it with better compenets and PSU into a nice case, and make it stereo at least.

[grosteph58]

2N3055 are good and strong transistors ,really home made amplifier and it runs goodly .Many years ago i used a steréo professional amplifier ,it was made with two pairs of 2n3055 trans/channel and give 200 watts and never failed .

[monkeymcmartin]

Crikey, this is BONKERS. Put it back in the junk cupboard.

[LOOPKOOL205]

wow for a tiny speaker it still sounds good...

[400exkid]

micky mouse wall paper??

[TheLightningStalker]

Awesome. Where did you get the circuit? Did you come up with it yourself or was it online? I'd like to see it. It's not pretty but neither is any of the stuff l build, so l guess l can feel your pain there. I Iike to think that l can do some designing, but a lot of times l think I'm not smart enough. My site is hxxp;//kickme,to/Iightningstal­ker. There's some schematics and stuff there if you're interested. Cheers from a fellow electronics nut.

[pj10b]

it would sound better if you put a back on it.

[coolbluelights]

wow where did you get the plans to make that? that's pretty darn cool!

[Ricgen09]

you could realy make acareer out of this .

[432621]

wtf hitler speaker keejejee

[rys5227]

ha ha good jod dude

[ingej32]

good jod?

[kulugu]

let me ask something do I still have to put mica under the transistor to make it work?

[mavallarino]

Nice, open baffle, powered monitor! Nice point to point wiring.

[Haley8nowhere]

Haha, nice! and, good feel of a non-digital sound!

I got the feeling that you can simply stick another speekerto the free space on the sidewall of the box hooked in parallel to the first.

But just the way it is now may be very cool for a lead guitar cuz you have th mids emphasized & you have distortion when needed!

[thebna89]

Nice mickey mouse wall paper

[alphadore]

This thing sounds out of this world!!!! You could make boutique gear for people who want that gritty transistor overloaded sound. Sounds really good on electronic stuff like that.

[twirlywirly55]

hi

nice video

dose anyone no what i could use a toroidal transformer for because i have 2 of them 1 12v and 1 9v but no uses

[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]

actually not to ramble on about this but its cool i hacked this water resistant wireless speaker/radio and made an amp for my ipod its the first one i hacked its a little tinny but when you turn it up its loud and doesnt sound all that bad

[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.

[coondogtheman1234]

i dont know why the hell they made those but i buy them to hack them, only the ones that have built in speakers because i hack them into amps I know the pin out on the little FM chip inside

[FIcaraudioBTL]

cool cool man we all got passion you is the vintage stuff mee too but you it extreme we in 2007 soon 2008 so man

[raymondleeleggs]

Sounds like an OLD transistor radio! :D

[emersiveav]

Id love to hear that amp playing on a quality loudspeaker system to see just how good it sounds. It seems pretty powerfull for its size I bet its pretty warm soundign on a good speaker.

[damusician]

do you know the title of that techno song? i love it and i want to download it.

[tubeie07]

Great fun making home made stuff... Nice work!

[speedyc395]

Awesome rap!!

That was a really nice preamp/amp. Nice design.

About the only homemade amp I made was about 6 years ago: On a breadboard, I made an AM receiver, with a preamp and amp. This was for a lab in class. Mine was somehow the best sounding one, with lots of bass and treble, and the AM didn't even sound like AM. Our one instructor went around and began pulling in other instructors into our class just to show them my project, hehe. I really should build another one.

[damusician]

nice amp and awesome song! that midrange looks like it came out of a late 1950's or early 1960's magnavox stereo console. that rap was hilarious especially when mentioning are names. roflmao!