Help with a little project I'd like to do.

[unreal89]

Hi, I just signed up because I'm interested in getting my extra Klipsch 2.1 Promedia sub working.

Long story short I had a problem with my Klipsch 2.1 Promedia speakers for my computer. Now that they are fixed I am left with one extra satellite and one subwoofer with the box and a busted amp. I never liked how the subwoofer would distort at the higher levels. Now that I have an extra 8" woofer with a ported box I wanted to try and get an amplifier board that I can use with it to get more bass without added distortion. The subwoofer is rated for 130w RMS at 4ohms I believe. Can you guys suggest a simple chip amp that I can use with this. For input I'd like to use a headphone jack and just split my laptop's output into two and have my klipsch system plug into one of the outputs and the extra sub into the other.

I hope this all makes sense to you guys. At least enough to point me in the right direction.

Thanks.

[danielwritesbac]

It sounds like you would enjoy a very inexpensive subwoofer amplifier from Parts Express, to take care of that subwoofer.

For the main stereo amp, a Stereo Classic kit from Audiosector, sounds like a nice place to start.

[unreal89]

Well the 100W dayton amp is $100 and I do not want to spend that much. Since I have the blown klipsch amp I thought I can make a little project out of it. I could use the transformer that it has, and just build a cheap chip amp. I was thinking of maybe on of those LM4780 I believe they are 120w. I'm just not sure of everything I would need.

Can i build a chip amp using the power from my klipsch transformer and just plug it into my laptop? Or do i need a pre-amp?

Can a small car amplifier be used? I know it needs a 12v source, so maybe the klipsch transformer can provide that.

Thanks

[Nordic]

Got a transformer?

[unreal89]

Yes... or are you mocking me?

[sek]

Hi Unreal,

What amplifier did the Klipsch module use? E.g. what chip or transistor types?

What usable parts does the remainder consist of? E.g. what transformer, what capacitors, what cooling arrangement, etc.?

A car amp usually needs a stabilized supply of relativly high current capability, something your trafo certainly won't be the best for. But ripping up the PSU connection inside a car amplifier and injecting the PSU of the Klipsch module could be an option.

Cheers,
Sebastian.

[unreal89]

the only chip i see says:

TL074CN
GK60116U
V6 GK CHN

and the company logo is ST

also the transistors say:

1st one:
IRF9640
I R 608P
KK Q5

2nd one:
IRF640N
I R 535P
G4 F8

those are the transistors with the tiny heat sink on the back.

There are also two 63v 4700 uF caps and two 35v 4700 uF caps.

There is also a blue box thing thats says:
GOODSKY
UDH-SS-124D

let me know if i can use these things to build a little chip amp.
As you can probably know, I don't know much about this stuff, but I'd like to experiment.

Thanks for the help so far.

[MJL21193]

Hi,
TL074 is an opamp - input stage for the amp.

IRF9640 and IRF640 are mosfets - output stage for the amp.

These capacitors are most likely power supply smoothing. The 35V caps are most likely for a +/- 15 V supply for the op amp.
The 63V ones say the main power supply is probably in the 30-50 volts (+/-) range. This may be too much for a chip amp. You will need to measure the voltage, but first you need to educate yourself about power supplies, so that you don't get shocked.

Rod Elliot's ESP site has tons of useful information.

[sek]

The UDH-SS-124D is a relais for speaker protection.

I'd say almost all components - except for the mosfet transistors - can be reused, even for the lower power requirements of a chipamp.

But you forgot to mention the transformer.

Cheers,
Sebastian.

[unreal89]

just curious, why cant i reuse the mofset transistors?