Newbie to Auido

Micah

Member
2001-11-28 8:45 am
I have a 6 channel computer sound card and i am wanting to build an amp for it to goto my 5 speaker and 1 sub. dose anyone know where i can find a pcb design of an amp that runs on 12v and has 6 channel input and output? i am very new to audio stuff so i don't know if what i am wanting to do is possable. if there is no 6 channel amp out there could i rig 6 seperate mono amp together? any help would be great


Many thanks
 
Dear Micah,

*)I don't know any 6 channel amplifier on just one pcb, so I think you have to build 6 mono amplifiers (or 3 stereo versions)

*)I don't know what kind of speakers you want to drive
( ?? ohm; ?? Watt)

*)If you want to use a power supply of 12V, the power of the amplifier will be (very) low. If you have 2 supplies of 12V then you can realise a supply with +12V, 0V (GND), -12V wich allowes more output-power

*)I will look after a schematic, but can you tell us some more details of your expections and your speakers.


best regards,

HB.
 

Micah

Member
2001-11-28 8:45 am
ok the speakers i want to driver are 5*180 watt speakers and a 1000w sub running all @ 8 ohms. for my power supply i am going to use Computer PSU's, they give out +5v,12v i can rig these up so i can get +10v/24 or +15v/36v

hope this info helps :)
 

paulb

Member
2001-06-01 4:53 pm
Calgary
There was a previous discussion about trying to use computer power supplies for an audio amp:
http://www.diyaudio.com/forums/showthread.php?threadid=861

He gave up, it's not practical because computers use low voltage / very high current, while audio has to involve the 8 ohm impedance of the speaker - for high power, you need high voltage.

I'm building an amp right now of about 75 watts per channel, it uses an 84-volt DC power supply (+/- 42V).

A switching inverter could be used to transform DC voltages, but this would probably be more complex than the rest of your amplifier.

The power levels you're talking about would be a complicated and expensive project. Far cheaper to buy something. Except for unusual cases, DIY stuff is not cheaper (it just sounds better).
 
You can't get enough power from a PC power supply to run all your speakers at full volume, and PC power supplies don't have a high dual voltage that you would need for your amp(s). You would need a different supply for the amps. Other than that, it would be fine. Just have an amp for each speaker. http://epanorama.net has many schematics for mono amps. Go to "Audio" then "Circuits to Build."
 

Micah

Member
2001-11-28 8:45 am
i will make a board my self :D i find it a little diffcult to read those numbers, could and ony write them done for me please? along with what part they are (r1,r3,c1....) Many Many thanks to whoever dose it. also i am thinking of making 5 of them for each speaker, will i have to make 5 PS's for them or will one do and how many amps will the input of 240v ac pull for them all?? as i can only pull a max of 20amps off my power sockets
 
The power supply shown in figure 2 is the 'classic' unregulated supply that MOST of us use in power amps. Rod Elliott uggests using a 300va transformer, so the max current you will get out is around 5A befour the voltage falls significantly.
However, if you wanted to use one PS to power 5 or 6 amps, then i would suggest at least 700w to 1kw transformer and up the smoothing caps to around 20,000uF each. I know this does sound expensive, but when the beasty is finished, it will make a serious surround sound setup. Another thing is that the you may like to power the subwoofer off a amp with seprate supply due to the high current demands that subs need.
If you still want to stick to 12v or whatever, you could think about useing the IC amps (found in car radios) that will supply around 30watts per channel. A recent artical was publish (last month i think) in elektor electronics for a computer surround sound amp. It was only 3 watts per channel though, because is you start stealing power from your computer (which has a 200-300watt power supply) your computer can have problems (hard disk dropout etc). Having said that, you could get a 12V 30Amp power supply from a radio meet quite cheaply.