Calling all amp builders!

[Green Machine Mowing]

has anyone incorperated a small amp into their computers?? you already have 5 and 12 VDc

thought of it earlyer and was wondering if anyone had done it.

[AJ]

Re: Calling all amp builders!

12vdc won't power much. If you had a supply that had high current + and -12vdc supplies you could power a small IC based amp, but most computer power supplies only have high current +12vdc lines and low current -12vdc supplies.

[ocool_15]

Re: Calling all amp builders!

Sonic Impact has a PCI card like that. The 12V supply, noise and space constraints would be issues.

[Green Machine Mowing]

Re: Calling all amp builders!

im not talking about a 1Kw sub amp maybe 15-20 wpc to run some small computer speakers, should beat the ones that come with computers!

[jgaustin]

Re: Calling all amp builders!

My son and I used a cheap-o microATX PSU to power a Pyramid car amp for his iPod jambox/portable speaker (his impression of clarkbradshaw's "Daytona"). Worked well. For around $15 we got 11 amps at +12VDC and a +5VDC line for a USB port to charge his iPod. I'll have a writeup of it sometime soon.

In retrospect, we probably should have done it differently, but I can't fault the PSU for that...

[ocool_15]

Re: Calling all amp builders!

15W into 4 ohms from 12V is often going to be a BTL amplifer like car decks use. A couple multimedia systems I've seen are like that.

[neildavis]

Re: Calling all amp builders!

Sonic Impact has a PCI card like that.

A card is probably the best solution for a low-powered amp. If you try to get power from any other place besides the motherboard, you end up getting noise into the input because the analog input gets referenced to the PC power supply rather than the analog ground. So it's really easy to pick up lots of switching noise whenever there is network activity or when disks spin up.

A much better solution is to build a separate power supply into the computer case, or to use an external supply. The picture shows an old case with a nice 50W stereo amp that I couldn't bear to throw away, so it's stashed up in the attic (any offers?). I've also got one of those 4-channel 100W Class D Sure amps mounted in a CDROM drive case. It uses a 24V external switching supply. I still need to finish off some wiring on it, but it would be available to a good home, also. I recently threw out a case which had 4 LM3886 circuit boards and a nice power supply. One of the amps had a problem and I didn't want to be tempted to fix it. The computer case on its side behind the one in the picture also has a 50W stereo amp--that's my measurement computer, although it doesn't get used much

Overall, it just makes more sense to me to mount the amplifiers in the speaker.

[jdclark]

Re: Calling all amp builders!

people have put chip amps in the 5.25 bays. But, there are issues with the power supple and feedback as mentioned above, I would rather integrate in to the speaker enclosures than the computer case.

[Adrian]

I used this kit. . .

. . . From electronics123.com : http://www.electronics123.com/s.nl/i...=8&category=33

It fired right up when i hooked it up to the 12V p/s lines on my computer. It really whoops azz too! Don't let the 6-10W power rating fool you it's real.

Adrian

[pres589]

Re: Calling all amp builders!

EMI make me nervous, pulling on the same power supply that drives a lot of other expensive hardware doesn't sweeten the deal. Get something external or build it into the housing of your speakers.

I like the idea of a chip amp per speaker.

[mike1234]

Re: Calling all amp builders!

Careful... many PC's are already pushed somewhat close to their PS limits especially if they've had updates such as extra HD's, high-end VC's, etc. If you REALLY want to share your PC's PS to power an amp you may want to upgrade the PC PS 1st. That's even if you go with an amp card.

[jdclark]

Re: Calling all amp builders!

Careful... many PC's are already pushed somewhat close to their PS limits especially if they've had updates such as extra HD's, high-end VC's, etc. If you REALLY want to share your PC's PS to power an amp you may want to upgrade the PC PS 1st. That's even if you go with an amp card.

For people who dont have a power hungry GPU and CPU (which is most), the PSU can be upgraded to something with WAY more power than needed for under $60.